Online Instructor’s Manual
to accompany
Introductory Circuit Analysis
Twelfth Edition
Robert L. Boylestad
Prentice Hall
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Contents
CHAPTER 1
1
CHAPTER 2
10
CHAPTER 3
15
CHAPTER 4
25
CHAPTER 5
32
CHAPTER 6
42
CHAPTER 7
56
CHAPTER 8
68
CHAPTER 9
92
CHAPTER 10
111
CHAPTER 11
130
CHAPTER 12
149
CHAPTER 13
156
CHAPTER 14
164
CHAPTER 15
174
CHAPTER 16
196
CHAPTER 17
203
CHAPTER 18
222
CHAPTER 19
252
CHAPTER 20
265
CHAPTER 21
279
CHAPTER 22
311
CHAPTER 23
318
CHAPTER 24
333
CHAPTER 25
342
CHAPTER 25
352
iii
___________________________________________________________________________________________
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10 9 8 7 6 5 4 3 2 1
ISBN-13: 978-0-13-504082-9
ISBN-10:
0-13-504082-5
Chapter 1
1.
2.
3.
4.
=
5.
6.
d 20,000 ft 1 mi 60 s 60 min
=
= 1363.64 mph
t
10 s 5,280 ft 1 min 1 h
1h
4 min
= 0.067 h
60 min
d
31 mi
=
= 29.05 mph
t 1.067 h
3 ft
100 yds
1 yd
1 mi
5,280 ft = 0.0568 mi
60 mi 1 h 1 min
= 0.0167 mi/s
h 60 min 60 s
t=
7.
a.
b.
c.
d
0.0568 mi
= 3.40 s
0.0167 mi/s
95 mi 5,280 ft 1 h 1 min
= 139.33 ft/s
h mi 60 min 60 s
d
60 ft
t=
= 0.431 s
139.33 ft/s
d 60 ft 60 s 60 min 1 mi
=
= 40.91 mph
t
1 s 1 min 1 h 5,280 ft
8.
9.
10.
11.
MKS, CGS, C =
12.
0.7378 ft - lb
1000 J
= 737.8 ft-lbs
1J
5
5
5
(F 32) (68 32) (36) = 20
9
9
9
SI: K = 273.15 + C = 273.15 + 20 = 293.15
Chapter 1
1
13.
3 ft 12 in. 2.54 cm
0.5 yd
= 45.72 cm
1 yd 1 ft 1 in.
14.
a.
°F = 2(°C) + 30° = 40° + 30° = 70°
b.
°F =
c.
very close
d.
30°C 90°F vs. 86°
5°C 40°F vs 41°
a.
14.6
b.
c.
1,046.1
d.
e.
3.14159 = 3.1
a.
14.60
b.
c.
1,046.06
d.
e.
3.14159 = 3.14
a.
14.603
b.
c.
1,046.060
d.
e.
3.14159 = 3.142
a.
104
15.
16.
17.
18.
9
9
(C) 32 (20) 32 = 68°
5
5
e. 100
b. 106
56.0
1
= 0.0625 = 0.1
16
56.04
1
= 0.0625 = 0.06
16
56.042
1
= 0.0625 = 0.063
16
c. 103
d. 103
c. 2.4 106
d. 60 103
f. 101
5 103
a.
15 103
e.
4.02 104 f. 2 1010
20.
a.
b.
c.
d.
4.2 103 + 48.0 103 = 52.2 103 = 5.22 104
90 103 + 360 103 = 450 103 = 4.50 105
50 105 6 105 = 44 105 = 4.4 104
1.2 103 + 0.05 103 0.4 103 = 0.85 103 = 850
21.
a.
b.
c.
d.
e.
f.
(102)(103) = 105 = 100 103
(102)(103) = 101 = 10
(103)(106) = 1 109
(102)(105) = 1 103
(106)(10 106) = 10
(104)(108)(1028) = 1 1024
19.
2
b.
Chapter 1
22.
a.
b.
c.
d.
(50 103)(2 103) = 100 100 = 100
(2.2 103)(2 103) = 4.4 100 = 4.4
(82 106)(1.2 106) = 98.4
(30 104)(4 103)(7 108) = 840 101 = 8.40 103
23.
a.
b.
c.
d.
e.
f.
102/104 = 102 = 10 103
102/103 = 105 = 10 106
104/103 = 107 = 10 106
107/102 = 1.0 109
1038/104 = 1.0 1042
100 / 10 2 = 101/102 = 1 103
24.
a.
b.
c.
d.
(2 103)/(8 105) = 0.25 108 = 2.50 107
(4 103)/(4 106) = 4/4 109 = 1 109
(22 105)/(5 105) = 22/5 100 = 4.4
(78 1018)/(4 106) = 1.95 1025
25.
a.
c.
(102)3 = 1.0 106
(104)8 = 100.0 1030
26.
a.
b.
c.
d.
27.
a.
(2 102)2 = 4 104
(5 103)3 = 125 109
(4 103)(3 103)2 = (4 103)(9 104) = 36 101 = 360
((2 103)(0.8 104)(0.003 105))3 = (4.8 103)3 = (4.8)3 (103)3
= 110.6 109 = 1.11 1011
(103)2 = 1.0 106
(10 2 )(10 4 )
= 102/103 = 1.0 105
3
10
3 2
(10 ) (10 2 ) (10 6 )(10 2 ) 10 4
4 = 1.0 108
4
4
10
10
10
3
4
(10 )(10 )
= 107/104 = 1.0 1011
4
10
b.
c.
d.
e.
(10 )(10 )
(10 ) 10
2 2
28.
a.
b.
c.
Chapter 1
(104)1/2 = 10.0 103
(107)9 = 1.0 1063
(1 104)3(102)/106 = (1012)(102)/106 = 1010/106 = 1.0 1016
2
f.
b.
d.
2
3
3
1
1
= 1.0 101
3
(10 )(10 ) 10
4
(3 10 2 ) 2 (10 2 )
= (9 104)(102)/(3 104) = (9 106)/(3 104) = 3 102 = 300
4
3 10
(4 10 4 ) 2 16 10 8
= 2 105
3
3
(20)
8 10
(6 104 ) 2
36 108
= 9.0 1012
2 2
4
(2 10 )
4 10
3
d.
(27 10 6 )1 / 3 3 10 2
= 1.5 107 = 150.0 109
5
5
2 10
2 10
e.
(4 10 3 ) 2 (3 10 2 ) (16 10 6 )(3 10 2 ) 48 10 8
= 24.0 1012
2 10 4
2 10 4
2 10 4
f.
(16 106)1/2(105)5(2 102) = (4 103)(1025)(2 102) = 8 1020 = 800.0 1018
g.
(3 103 )3 1.60 102 (2 102 )(8 104 )
5 2
(7 10 )
2
1/ 2
(27 109 )(2.56 104 )(16 102 )1/ 2
49 1010
(69.12 105 )(4 101 ) 276.48 106
49 1010
49 1010
4
3
= 5.64 10 = 56.4 10
29.
Scientific:
Engineering:
30.
Scientific
Engineering:
4
a.
b.
2.05 × 101
5.04 × 104
c.
6.74 × 104
d.
4.60 × 102
a.
b.
20.46 × 100
50.42 × 103
c.
674.00 × 106
d.
46.00 × 103
a.
b.
5.0 × 102
4.5 × 101
c.
d.
1/32 = 0.03125 = 3.125 × 102
3.14159 = 3.142 × 100
a.
b.
50.0 × 103
0.045 × 103
c.
d.
31.25 × 103
3.142 × 100
Chapter 1
+2
31.
a.
6 104 = 0.06 10+6 = 0.06 × 10+6
3
3
b.
0.4 103 = 400 106 = 400 × 106
+3
2
c.
+3
50 105 = 5000 103 = 5 106 = 0.005 109 = 0.005 × 109
3
+2
3
3
+4
d.
+3
3
12 107 = 0.0012 103 = 1.2 106 = 1200 109 = 1200 × 109
4
+3
+3
3
32.
a.
0.05 100 s = 50 103 s = 50 ms
+3
+3
b.
2000 106 s = 2 103 s = 2 ms
3
3
c.
0.04 103 s = 40 106 s = 40 s
+3
+6
d.
8400 1012 s 0.0084 106 s = 0.0084 s
6
Chapter 1
5
+3
increase by 3
100
e.
100 103 103 m = 0.1 103 m = 0.1 km
3
33.
34.
35.
6
a.
60 s
1.5 min
= 90 s
1 min
b.
60 min 60 s
2 × 102 h
= 72 s
1 h 1 min
c.
1 s
0.05 s 6 = 0.05 106 s = 50 103 s
10 s
d.
1 mm
0.16 m 3 = 0.16 103 mm = 160 mm
10 m
e.
1 ns
1.2 107 s 9 = 1.2 102 ns = 120 ns
10 s
f.
1 min 1 h 1 day
4 108 s
= 4629.63 days
60 s 60 min 24 h
a.
100 cm
= 8000 103 cm = 8 cm
80 103 m
1m
b.
1 m 1 km
60 cm
= 60 105 km
100 cm 1000 m
c.
1 m
12 × 103 m 6 = 12 103 × 10+6 m = 12 × 103 m
10 m
d.
1m 1m
4
2
60 cm2
= 60 10 m
100 cm 100 cm
a.
1m
100 in.
= 2.54 m
39.37 in.
b.
12 in.
4 ft
1 ft
1m
39.37 in. = 1.22 m
Chapter 1
c.
d.
36.
37.
38.
39.
40.
41.
4.45 N
6 lb
= 26.7 N
1 lb
1 N 1 lb
60 103 dynes 5
= 0.13 lb
10 dynes 4.45 N
e.
1 in. 1 ft
150,000 cm
= 4921.26 ft
2.54 cm 12 in.
f.
5280 ft 12 in. 1 m
0.002 mi
= 3.22 m
1 mi 1 ft 39.37 in.
1 yd
5280 ft
= 1760 yds
3 ft
12 in. 1 m
5280 ft
= 1609.35 m, 1.61 km
1 ft 39.37 in.
5280 ft,
60 mi 5280 ft
h
1 mi
12 in.
1 ft
1m
39.37 in.
1h
60 min
1000 m 39.37 in. 1 ft 1 mi
10 km
1 km 1 m 12 in. 5280 ft
d 6.214 mi
1 mi
=
= 40.39 min
,t=
1 mi
6.5 min
6.5 min
1 min
60 s
= 26.82 m/s
= 6.214 mi
3 ft 12 in.
100 yds
= 3600 in 3600 quarters
1 yd 1 ft
500 mi
= 8.33 h = 8 h:19.8 min
60 mi/h
d 500 mi
= 6.67 h = 6h:40.2 min
75 mph: t =
75 mi/h
difference = 1h:28.6 minutes
60 mph:
t=
d
cm
0.016 h 60 min 60 s 1 m = 345.6 m
d = t = 600
s
1 h 1 min 100 cm
Chapter 1
7
42.
14 ft
d = 86 stories
story
d
d 1605 steps
1 minute
t
802.5 seconds
= 13.38 minutes
2
steps
t
60 seconds
second
=
43.
44.
14 ft
1 mile
d = (86 stories)
1204 ft
= 0.228 miles
5,280 ft
story
min 10.22 min
= 44.82 min/mile
mile 0.228 miles
5 min
1 mile 5,280 ft 1056 ft
,
mile
5 min 1mile minute
a.
1 Btu
5 J
= 4.74 103 Btu
1054.35 J
b.
1 m3
1 gallon
4 3
24 ounces
= 7.1 10 m
128 ounces 264.172 gallons
c.
86,400 s
5
1.4 days
= 1.21 10 s
1
day
d.
264.172 gallons
1 m3
1 m3
46.
6(4 × 2 + 8) = 96
47.
(42 + 6/5)/3 = 14.4
48.
2
5
3
8 pints
= 2113.38 pints
1 gallon
2
2
= 5.044
49.
MODE = DEGREES: cos 21.87 = 0.928
50.
MODE = DEGREES: tan1(3/4) = 36.87
51.
8
14 ft
distance = 86 stories
= 1204 ft
story
d
d
1204 ft
= 1.14 minutes
t
t
1056 ft
min
=
45.
1 step
9 = 1605 steps
ft
12
400 /(6
2
10 / 5) = 7.071
Chapter 1
52.
205 106
53.
1.20 1012
54.
6.667 106 + 0.5 106 = 7.17 106
Chapter 1
9
Chapter 2
1.
2.
a.
F= k
Q1Q2 (9 109 )(1 C)(2 C)
= 18 109 N
r2
(1 m) 2
b.
F=k
Q1Q2
(9 109 )(1 C)2 C
=
= 2 109 N
(3 m) 2
r2
c.
F= k
Q1Q2 (9 109 )(1 C)(2 C)
= 0.18 109 N
2
2
r
(10 m)
d.
Exponentially,
a.
r = 1 mi:
3.
r3 10 m
F
18 109 N
= 10 while 1
= 100
r1 1 m
F2 0.18 109 N
5280 ft 12 in. 1 m
1 mi
= 1609.35 m
1 mi 1 ft 39.37 in.
kQ1Q2 (9 109 )(8 106 C)(40 10-6 C) 2880 103
F=
r2
(1609.35 m)2
2.59 106
= 1.11 N
b.
r =10 ft:
12 in. 1 m
10 ft
= 3.05 m
1 ft 39.37 in.
kQ1Q2 2880 103 2880 103
= 0.31 N
F=
9.30
r2
(3.05 m) 2
c.
1 in. 1 m
= 1.59 mm
16 39.37 in.
kQ1Q2
2880 103
2880 103
1138.34 103 N
r2
(1.59 103 m) 2 2.53 106
= 1138.34 kN
F=
4.
5.
Q1 = Q2 = Q; F1
6.
F=
10
kQ1Q2
r
r2
F1r12
kQ 2
kQ 2 k
2
;
Q
F
2
2
k
r12
r22
r2
kQ1Q2
F
F1r12
r12
and
F1
F
2
r22
k
(9 109 )(20 106 ) 2
= 10 mm
3.6 104
Chapter 2
7.
F=
a.
b.
kQ1Q2
kQ Q
1.8 1 22 kQ1Q2 = 4(1.8) = 7.2
2
r
(2 m)
kQ1Q2
7.2
= 72 mN
2
r
(10) 2
Q1/Q2 = 1/2 Q2 = 2Q1
7.2 = kQ1Q2 = (9 109)(Q1)(2Q1) = 9 109 2Q12
F=
7 .2
7 .2
Q12 Q1
= 20 C
9
18 10
18 109
Q2 = 2Q1 = 2(2 105 C) = 40 C
W
1.2 J
= 60 kV
Q 20 C
8.
V=
9.
W = VQ = (60 V)(8 mC) = 0.48 J
10.
Q=
6.242 1018 electrons
W 120 J
15
= 6 mC
= 37.45 × 10 electrons
V
20 mV
1C
11.
Q=
W 72 J
=8C
V
9V
12.
a.
b.
W = QV = (1 × 1012 electrons)(40 V) = 40 × 1012 eV
1C
40 × 1012 eV
18
= 6.41 μJ
6.242
10
electrons
13.
I=
Q 12 mC
= 4.29 mA
t
2.8 s
14.
I =
Q
312 C
= 2.60 A
t (2)(60 s)
15.
Q = It = (40 mA)(0.8)(60 s) = 1.92 C
16.
Q = It = (250 mA)(1.2)(60 s) = 18.0 C
17.
t=
18.
Q 6 mC
=3s
I
2 mA
1C
21.847 1018 electrons
18
= 3.5 C
6.242 10 electrons
Q 3.5 C
I=
= 0.29 A
t
12 s
Chapter 2
11
19.
Q = It = (4 mA)(90 s) = 360 mC
6.242 1018 electrons
18
360 mC
= 2.25 10 electrons
1
C
20.
I=
21.
22.
Q
86 C
= 1.194 A > 1 A (yes)
(1.2)(60 s)
t
1C
0.84 1016 electrons
18
= 1.346 mC
6.242
10
electrons
Q 1.346 mC
I=
= 22.43 mA
t
60 ms
a.
Q = It = (2 mA)(0.01 s) = 2 1011 C
6.242 1018 electrons 1 ¢
2 1011 C
1C
electron
= 1.25 108 ¢ = $1.25 106 = 1.25 million
Q = It = (100 A)(1.5 ns) = 1.5 1013 C
6.242 1018 electrons $1
1.5 1013 C
= 0.94 million
1C
electron
(a) > (b)
b.
23.
24.
Q = It = (200 103 A)(30 s) = 6 C
W 40 J
V=
= 6.67 V
Q 6C
420 C
Q = It =
(0.5 min) = 210 C
min
W
742 J
= 3.53 V
V=
Q 210 C
W 0.4 J
= 0.0167 C
V
24 V
Q 0.0167 C
I=
= 3.34 A
t 5 103 s
25.
Q=
26.
I=
27.
Ah = (0.8 A)(75 h) = 60.0 Ah
28.
t(hours) =
12
Ah rating 200 Ah
=5A
40 h
t (hours)
Ah rating 32 Ah
= 25 h
I
1.28 A
Chapter 2
29.
60 min 60 s
6
40 Ah(for 1 h): W1 = VQ = VIt = (12 V)(40 A)(1 h)
1 min = 1.728 10 J
1
h
60
min
60
s
6
60 Ah(for 1 h): W2 = (12 V)(60 A)(1 h)
1 min = 2.592 10 J
1
h
Ratio W2/W1 = 1.5 or 50% more energy available with 60 Ah rating.
1 min 1 h
= I(16.67 103 h)
For 60 s discharge: 40 Ah = It = I 60 s
60 s 60 min
40 Ah
= 2400 A
and I =
16.67 10-3 h
1 min 1 h
60 Ah = It = I 60 s
= I(16.67 103 h)
60 s 60 min
60 Ah
= 3600 A
and I =
16.67 10-3 h
I2/I1 = 1.5 or 50 % more starting current available at 60 Ah
30.
0.75(18 Ah) = 13.5 Ah 250 mA
31.
(18 Ah 15.5 Ah)/18 Ah × 100% = 13.89%
32.
At 100 mA, discharge time 120 H; At 25 mA, discharge time 425 h;
300 h more at 25 mA
33.
I=
3 Ah
= 500 mA
6.0 h
60 min 60 s
Q = It = (500 mA)(6 h)
= 10.80 kC
1 h 1 min
W = QV = (10.8 kC)(12 V) 129.6 kJ
34.
35.
36.
37.
a.
b.
c.
Chapter 2
2.54 cm
= 1.27 cm
0.5 in
1 in
30 kV
= 38.1 kV
1.27 cm
cm
270 kV
1.27 cm
= 342.9 kV
cm
342.9 kV:38.1 kV = 9:1
13
38.
39.
40.
41.
14
Chapter 2
Chapter 3
1.
a.
0.5 in. = 500 mils
b.
1000 mils
0.02 in.
= 20 mils
1 in.
c.
1
1000 mils
in. = 0.25 in.
= 250 mils
4
1 in.
d.
e.
2.
3.
39.37 in 1000 mils
10 mm = 10 × 103 m
= 393.7 mils
1 m 1 in
3
12 in. 10 mils
0.01 ft
= 120 mils
1 ft 1 in.
f.
1 in. 1000 mils
0.1 cm
= 39.37 mils
2.54 cm 1 in.
a.
ACM = (30 mils)2 = 900 CM
b.
0.016 in. = 16 mils, ACM = (16 mils)2 = 256 CM
c.
1"
= 0.125" = 125 mils, ACM = (125 mils)2 = 15.63 103 CM
8
d.
1 in.
1 cm
2.54 cm
e.
12 in. 1000 mils
2
3
0.02 ft
1 in. = 240 mils, ACM = (240 mils) = 57.60 10 CM
1
ft
f.
39.37 in. 1000 mils
= 157.48 mils, ACM = (157.48 mils)2 = 24.8 × 103 CM
4 × 103 m
1 m 1 in
1000 mils
2
3
1 in. = 393.7 mils, ACM = (393.7 mils) = 155 10 CM
ACM = (dmils )2 dmils =
ACM
a.
d = 1600 CM = 40 mils = 0.04 in.
b.
d=
820 CM = 28.64 mils = 0.029 in.
c.
d=
40,000 CM = 200 mils = 0.2 in.
Chapter 3
15
d.
d=
625 CM = 25 mils = 0.025 in.
e.
d=
6.25 CM = 2.5 mils = 0.0025 in.
f.
d=
3 103 CM = 54.77 mils = 0.055 in.
4.
0.02 in. = 20 mils, ACM = (20 mils)2 = 400 CM
(200 )
l
= 5.19
R = = (10.37)
400 CM
A
5.
a.
A=
80
l
= 544 CM
17
R
2 .5
b.
d=
ACM 544 CM = 23.32 mils = 23.3 103 in.
6.
7.
1 "
= 0.03125" = 31.25 mils, ACM = (31.25 mils)2 = 976.56 CM
32
l
RA (2.2 )(976.56 CM)
= 3.58 ft
R= l=
R
600
a.
ACM =
d=
larger
c.
smaller
=
9.
a.
b.
c.
16
942.73 CM = 30.70 mils = 30.7 103 in.
b.
8.
l
(10.37)(300)
=
= 942.73 CM
3.3
A
RA (500 )(94 CM)
= 47 nickel
l
1000
1/32 = 0.03125 = 31.25 mils, ACM = (31.25 mils)2 = 976.56 CM
l
RA (3.12 )(976.56 CM)
R=
l
= 293.82 ft
A
10.37
293.82 1000
(5)(293.82)
x
= 1.47 lbs
x
5 lb
1000
9
9
C 32 (40) 32 = 40°
5
5
9
9
105° C: F = C 32 (105) 32 = 221°
5
5
F° = 40° 221°
40° C: F =
Chapter 3
10.
a.
3
0.375 = 375 mils
8
4.8 = 4800 mils
4 / CM
6
A = (375 mils)(4800 mils) = 1.8 × 106 sq. mils
= 2.29 × 10 CM
1
sq
mil
b.
11.
a.
1
= 0.083 in. = 83 mils
12
ACM = = (83 mils)2 = 6.89 × 103 CM
2.29 106 CM
(#12)
= 332.37 wires
6.89 103 CM
3" = 3000 mils, 1/2" = 0.5 in. = 500 mils
Area = (3 103 mils)(5 102 mils) = 15 105 sq. mils
4 / CM
5
15 105 sq mils
= 19.108 10 CM
1 sq mil
R=
b.
l
(10.37)(4)
= 21.71
=
A 19.108 105 CM
l
(17)(4)
=
= 35.59
A 19.108 105 CM
Aluminum bus-bar has almost 64% higher resistance.
R=
12.
l2 = 2l1, A2 = A1/4, 2 = 1
2l2
R2
2l A
l A
A
2 22 1 1 1 =8
1l1
R1
1l1 A2 l1 A1 / 4
A1
and R2 = 8R1 = 8(0.2 ) = 1.6
R = 1.6 0.2 = 1.4
13.
A=
d 2
4
d=
4A
4(0.04 in.2 )
= 0.2257 in.
dmils = 225.7 mils
ACM = (225.7 mils)2 = 50,940.49 CM
l
1 1
R1
lA
lA
A1
11 2 1 2
(1 = 2)
R2 l2
2l2 A1 l2 A1
2
A2
R l A (800 m)(300 ft)(40,000 CM)
= 942.28 m
and R2 = 1 2 1
(200 ft)(50,940.49 CM)
l1 A2
Chapter 3
17
14.
a.
b.
15.
#12 = 6,529.9 CM, #14 = 4,106.8 CM
6,529.9 CM 4,106.8 CM
100% = 59% larger
4,106.8 CM
#12 20 A
#12 6,529.9 CM
= 1.33,
= 1.59
#14 4,106.8 CM
#14 15 A
Imax ratio = 1.33 vs Area ratio = 1.59
1.59 1.33
100% = 19.55% higher ratio for area
1.33
a.
#9 13,094 CM
= 2 yes
#12 6,529.9 CM
b.
#0 105,530 CM
= 16.16 yes
#12 6,529.9 CM
#0 150 A
= 7.5
#12 20 A
16.
a.
b.
17.
18.
18
#10 10,381 CM
10.16 10 yes
# 20 1,021.5 CM
# 20 1,021.5 CM
= 103.28
# 40
9.89 CM
yes 100
l (10.37)(30) 311.1 CM
= 51,850 CM #3
R
6 m
6 103
but 110 A #2
a.
A=
b.
A=
a.
A/CM = 230 A/211,600 CM = 1.09 mA/CM
b.
1.09 mA 1 CM 1000 mils 1000 mils
= 1.39 kA/in.2
CM sq mils 1 in. 1 in.
4
c.
1 in.2
2
5 kA
= 3.6 in.
1.39 kA
l (10.37)(30) 311.1 CM
= 103,700 CM #0
R
3 m
3 10 3
Chapter 3
19.
20.
234.5 10 234.5 80
,
2
R2
R2 =
(314.5)(2 )
= 2.57
244.5
236 0 236 100
R2
0.02
(0.02 )(336)
= 0.028
R2 =
236
5
5
(F 32) (32 32) = 0 (=32F)
9
9
5
C = (68 32) 20 (=68F)
9
234.5 20 234.5 0
4
R2
(234.5)(4 )
= 3.69
R2 =
254.5
21.
C=
22.
a.
b.
c.
d.
Chapter 3
5
5
F 32 (70 32) = 21.11°
9
9
5
°C = (60 32) = 15.56°
9
234.5 21.11 234.5 15.56
0.025
R2
(250.06)(0.025 )
= 24.46 mΩ
R2 =
255.61
°C =
5
(50 32) = 10°
9
234.5 21.11 234.5 10
0.025
R2
(244.5)(0.025 )
= 23.91 mΩ
R2 =
255.61
°C =
Part a: 25 mΩ 24.46 mΩ = 0.54 mΩ
Part b: 24.45 mΩ 23.91 mΩ = 0.55 mΩ
Linear 40°F 23.91 mΩ 0.55 mΩ = 23.36 mΩ
5
(30 32) = 34.44°
9
234.5 21.11 234.5 34.44
25 m
R2
(25 m)(200.06)
R2 =
= 19.57 mΩ
255.61
Yes, 25 mΩ 19.57 mΩ = 5.43 mΩ
°C =
19
e.
23.
a.
b.
24.
5
(120 32) = 48.89°
9
234.5 21.11 234.5 48.89
25 m
R2
(25 m)(283.39)
= 27.72 mΩ
R2 =
255.61
Yes, 2.72 mΩ
°C =
234.5 4 234.5 t2
,
1
1 .1
234.5 4 234.5 t2
,
1
0.1
t2 = 27.85C
t2 = 210.65C
68F 20C
a.
234.5+20 234.5 T2
1
2
2(254.5)
234.5 T2
1
T2 274.5C
b.
#10 = 0.9989 /1000
c.
d mils ACM 10,381 CM 101.89 mils
din = 0.102 in
25.
26.
20
1
10
1
1
1
= 0.003929 0.00393
Ti 20C 234.5 20 254.5
a.
20 =
b.
R = R20[1 + 20(t 20C)]
1 = 0.8 [1 + 0.00393(t 20)]
1.25 = 1 + 0.00393t 0.0786
1.25 0.9214 = 0.00393t
0.3286 = 0.00393t
0.3286
= 83.61C
t=
0.00393
R = R20[1 + 20(t 20C)]
= 0.4 [1 + 0.00393(16 20)] = 0.4 [1 0.01572] = 0.39
Chapter 3
27.
Table: 1000 of #12 copper wire = 1.588 @ 20C
5
5
C = (F 32) = (115 32) = 46.11C
9
9
R = R20[1 + 20(t 20C)]
= 1.588 [1 + 0.00393(46.11 20)]
= 1.75
28.
R =
29.
R =
30.
a.
31.
10 k 3.5 k = 6.5 k
32.
6.25 k and 18.75 k
33.
34.
a.
b.
c.
d.
e.
820 5%, 820 41 , 779 861
220 10%, 220 22 , 198 242
91 k 20%, 91 k 18.2 k, 77.8 k 109.2 k
9.1 k 5%, 9100 455 , 8,645 9,555 k
3.9 MΩ 20%, 3.9 MΩ 0.78 MΩ, 3.12 MΩ 4.68 M
35.
a.
b.
c.
d.
68 = Blue, Gray, Black, Silver
0.33 = Orange, Orange, Silver, Silver
22 k = Red, Red, Orange, Silver
5.6 M = Green, Blue, Green, Silver
36.
a.
10 20%
8
15 Ω ± 20%
12
10 Ω ± 10%
9
15 Ω ± 10%
13.5
Rnominal
22
(PPM)( T) =
(200)(65 20) = 0.198
6
10
106
R = Rnominal + R = 22.198
Rnominal
100
(PPM)( T) =
(100)(50 20) = 0.30
6
10
106
R = Rnominal + R = 100 + 0.30 = 100.30
b.
37.
38.
2 times larger
b.
4 times larger
no overlap, continuance
12
18
no overlap
11
16.5
470 Ω ± 10% = 470 Ω ± 47 Ω
= 423 Ω 517 Ω
Yes
No change
Chapter 3
21
39.
a.
b.
c.
d.
621 = 62 101 = 620 = 0.62 k
333 = 33 103 = 33 k
Q2 = 3.9 102 = 390
C6 = 1.2 106 = 1.2 M
40.
a.
G=
1
1
= 8.33 mS
R 120
b.
G=
1
= 0.25 mS
4 k
c.
G=
a.
Table 3.2, /1000 = 1.588
1
1
G=
= 629.72 mS
R 1.588
A 6529.9 CM (Table 3.2)
= 629.69 mS (Cu)
or G =
l
(10.37)(1000)
b.
G=
6529.9 CM
= 384.11 mS (Al)
(17)(1000)
a.
G1 =
1
1
1
= 100 mS, G2 =
= 50 mS, G3 =
= 10 mS
10
20
100
b.
G2:G1 = 50 mS: 100 mS = 1:2 whereas R2:R1 = 20 Ω:10 Ω = 2:1. The rate of change is
the same although one is increasing and the other decreasing.
c.
inverse linear
41.
42.
43.
1
= 0.46 S
2.2 M
Ga > Gb > Gc vs. Rc > Rb > Ra
l
2
5
2
A1 = A1, l2 = 1 l1 1 , 2 = 1
3
3
3
3
A
l1
1 1
3 A1 1
G1
l1
l A
22 1
A2 1l1 A2
5 5
G2
2
l1 A1
l2
3
A2 = 1
G2 = 5G1 = 5(100 S) = 500 S
44.
45.
46.
22
Chapter 3
47.
48.
1
2.54 cm
in. = 0.083 in.
= 0.21 cm
12
1 in.
d2
(3.14)(0.21 cm) 2
= 0.035 cm2
4
4
RA (2 )(0.035 cm 2 )
= 40,603 cm = 406.03 m
l=
1.724 106
A=
49.
a.
1 " 2.54 cm
2.54 cm
= 1.27 cm, 3 in.
= 7.62 cm
2 1"
1 in .
12 in. 2.54 cm
4 ft
= 121.92 cm
1 ft 1 in.
l (1.724 x 10 -6)(121.92 cm)
R=
= 21.71 Ω
A
(1.27 cm)(7.62 cm)
(2.825 106 )(121.92 cm)
= 35.59 Ω
A
(1.27 cm)(7.62 cm)
b.
R=
c.
increases
d.
decreases
= 100 d =
=
250 106
= 2.5 cm
100
50.
Rs =
51.
R l (150 )(1/ 2 in.)
R = Rs l w = s =
= 0.15 in.
R
500
w
52.
a.
d = 1 in. = 1000 mils
ACM = (103 mils)2 = 106 CM
RA (1 m)(106 CM)
1 =
= 1 CM-/ft
l
103 ft
b.
1 in. = 2.54 cm
d 2 (2.54 cm)2
A=
= 5.067 cm2
4
4
12 in. 2.54 cm
l = 1000 ft
= 30,480 cm
1 ft 1 in.
d
2 =
Chapter 3
100
RA (1 m)(5.067 cm 2 )
= 1.66 107 -cm
l
30,480 cm
23
c.
k=
2 1.66 107 -cm
= 1.66 107
1 CM- / ft
1
53.
54.
55.
56.
57.
58.
a.
50C specific resistance 105 -cm
50C specific resistance 500 -cm
200C specific resistance 7 -cm
b.
negative
c.
No
d.
=
a.
Log scale:
10 fc 3 k
100 fc 0.4 k
b.
negative
c.
no—log scales imply linearity
d.
1 k 30 fc
10 k 2 fc
R
10 k 1 k
=
= 321.43 /fc
fc
30 fc 2 fc
59.
cm 300 30 270 cm
3.6 -cm/C
125 50
75 C
T
and
60.
24
a.
@ 0.5 mA, V 195 V
@ 1 mA, V 200 V
@ 5 mA, V 215 V
b.
Vtotal = 215 V 195 V = 20 V
c.
5 mA:0.5 mA = 10:1
compared to
215 V: 200 V = 1.08:1
R
= 321.43 /fc
fc
Chapter 3
Chapter 4
1.
V = IR = (5.6 mA)(220 ) = 1.23 V
2.
I=
V 24 V
= 3.53 A
R 6.8
3.
R=
V
24 V
= 16 k
=
I 1.5 mA
4.
I=
12 V
V
= 300 A
R 40 103
5.
V = IR = (3.6 A)(0.02 M) = 0.072 V = 72 mV
6.
I=
V 120 V
= 2.4 mA
R 50 k
7.
R=
V 120 V
= 54.55
=
I 2.2 A
8.
I=
V 120 V
= 15 mA
R 8 k
9.
R=
V 120 V
=
= 28.57
I 4.2 A
10.
R=
V
4.5 V
= 36
=
I 125 m A
11.
R=
V 24 mV
= 1.2 k
=
I 20 A
12.
V = IR = (12 A)(0.5 ) = 6 V
13.
a.
R=
V 120 V
= 12.63
=
I 9.5 A
b.
60 min 60 s
t = 2 h
= 7200 s
1 h 1 min
W = Pt = VIt
= (120 V)(9.5 A)(7200 s)
= 8.21 106 J
14.
V = IR = (2.4 A)(3.3 M) = 7.92 V
15.
Chapter 4
25
16.
b.
17.
18.
19.
20.
P=
21.
t=
22.
a.
b.
(0.13 mA)(500 h) = 65 mAh
W
t
540 J
540 J
= 2.25 W
60 s
240 s
4 min
1 min
W 640 J
= 16 s
P 40 J/s
60 min 60 s
8 h
= 28,800 s
1 h 1 min
W = Pt = (2 W)(28,000 s) = 57.6 kJ
kWh =
(2 W)(8 h)
= 16 103 kWh
1000
23.
P = VI = (3 V)(1.4 A) = 4.20 W
W
12 J
= 2.86 s
t=
P 4.2 W
24.
P = EI = (6 V)(750 mA) = 4.5 W
25.
P = I2R = (7.2 mA)2 4 k = 207.36 mW
26.
P = I2R I =
27.
I=
28.
I=
29.
E=
26
P
R
240 mW
= 10.44 mA
2.2 k
P
2W
= 129.10 mA
R
120
V = IR = (129.10 mA)(120 ) = 15.49 V
E
22 V
= 1.31 mA
R 16.8 k
P = I2R = (1.31 mA)2 16.8 k = 28.83 mW
60 min 60 s
W = Pt = (28.83 mW) 1 h
= 103.79 J
1 h 1 min
P 324 W
= 120 V
I
2.7 A
Chapter 4
30.
I=
P
R
1W
= 461.27 A
4.7 M
no
PR (42 mW)(2.2 k) 92.40 = 9.61 V
31.
V=
32.
P = VI, I =
33.
V=
34.
a.
P = EI and I =
b.
Ah rating = (0.13 mA)(500 h) = 66.5 mAh
P 100 W
= 0.833 A
V 120 V
V
120 V
R=
= 144.06
I 0.833 A
P 450 W
= 120 V
I 3.75 A
V 120 V
R=
= 32
I 3.75 A
P 0.4 103 W
= 0.13 mA
E
3V
P
100 W
5 103 = 70.71 mA
R
20 k
V = PR (100 W)(20 k) = 1.42 kV
35.
I=
36.
P = EI = (220 V)(30 A) = 6.6 kW
6.6 kW
= 8.85 HP
PHP =
746 W/HP
37.
a.
V 2 12 V 2
W = Pt =
t
60 s = 86.4 J
R 10
b.
Energy doubles, power the same
39.
40.
1
4 weeks
12 h 3
[5 months] = 260 h
week 1 month
(230 W)(260 h)
kWh =
= 59.80 kWh
1000
a.
Chapter 4
60 min 60 s
W = Pt = (60 W)(10 h)
= 2.16 × 106 Ws
1 h 1 min
27
41.
42.
b.
1 Ws = 1 J 2.16 × 106 J
c.
W = Pt = (60 W)(10 h) = 600 Wh
d.
600 Wh
= 0.6 kWh
1000 W/1 kWh
e.
Cost = (0.6 kWh)(11 ¢/kWh) = 6.6 ¢
a.
kWh =
b.
I=
c.
Plost = Pi Po = Pi Pi = Pi(1 ) = 120 kW(1 0.82) = 21.6 kW
Pt
(21.6 kW)(10 h)
= 216 kWh
kWhlost =
1000
1000
44.
28
P 120 103 W
= 576.92 A
E
208 V
$1.00
= 9.09
11¢
Pt
(kWh)(1000) (9.09)(1000)
kWh =
= 36.36 h
t
1000
P
250 W
#kWh =
t=
43.
Pt
(1000)(kWh) (1000)(1200 kWh)
P
= 120 kW
1000
P
10 h
(kWh)(1000) (11.11)(1000)
= 2.32 h
P
4800
a.
$74
= $2.39/day
31 days
b.
$2.39 / day
= 16¢/h
15 h/day
c.
16¢
= 1.45 kWh
11¢/kWh
d.
1.45 kWh
= 24.16 24 bulbs
60 W
e.
no
$1.00
= 9.09 kWh
11¢/kWh
9.09 kWh
= 48.61 h
187 W
Chapter 4
45.
46.
47.
t = 5 h/day(365 days) = 1825 h
P t (339 W)(1825 h)
= 618.68 kWh
kWh =
1000
1000
Cost = (618.68 kWh)(11¢/kWh) = $68.05
P t (213 W)(1825 h)
= 388.73 kWh
kWh =
1000
1000
Cost = (388.73 kWh)(11¢/kWh) = $42.76
Cost Savings = $68.05 $42.76 = $25.29
P t (78 W)(4 h/day)(31 days)
= 9.67 kWh
1000
1000
Cost = (11¢/kWh)(9.67 kWh) = $1.06
kWh =
a.
P = EI = (120 V)(100 A) = 12 kW
b.
746 W
PT = 5 hp
+ 3000 W + 2400 W + 1000 W
hp
= 10,130 < 12,000 W (Yes)
c.
W = Pt = (10.13 kW)(2 h) = 20.26 kWh
(1600 W)(6 h) (1200 W)(1/4 h) (4800 W)
48.
kWh =
1h
1
h (900 W) 10 min
2
60 min)
(200 W)(2 h) (50 W)(3.5 h)
1000
9600 Wh +300 Wh 2400 Wh + 150 Wh 400 Wh + 175 Wh
=
= 13.025 kWh
1000
(13.025 kWh)(11¢/kWh) = 1.43¢
(200 W)(4 h) (6)(60 W)(6 h) + (1200 W) 20 min
49.
kWh =
1h
60 min
1
6
(175 W)(3.5 h) + (250 W) 2 h (30 W)(8 h)
1000
800 Wh 2160 Wh + 400 Wh + 612.5 Wh + 541.67 Wh + 240 Wh
=
= 4.754 kWh
1000
(4.754 kWh)(11¢/kWh) = 52.29¢
50.
=
51.
=
Po
100%
Pi
746 W
hp
373
100%
100% = 90.98%
410 W
410
(0.5 hp)
P (1.8 hp)(746 W/hp)
Po
, Pi = o
= 1960.29 W
Pi
0.685
P 1960.29 W
Pi = EI, I = i
= 16.34 A
E
120 V
Chapter 4
29
52.
=
Po
(0.8 hp)(746 W/hp)
596.8
100%
100%
100% = 67.82%
Pi
(4 A)(220 V)
880
53.
a.
Pi = EI = (120 V)(1.8 A) = 216 W
Pi = Po + Plost, Plost = Pi Po = 216 W 50 W = 166 W
b.
% =
54.
Pi = EI =
55.
a.
b.
c.
Po
Po
50 W
100% =
100% = 23.15%
216 W
Pi
I=
Po (3.6 hp)(746 W/hp)
= 16.06 A
=
E
(0.76)(220 V)
(2 hp)(746 W/hp)
Pi = P o =
= 1657.78 W
0.9
Pi = EI = 1657.78 W
(110 V)I = 1657.78 W
1657.78 W
= 15.07 A
I=
110 V
Po
(2 hp)(746 W/hp)
= 2131.43 W
0.7
Pi = EI = 2131.43 W
(110 V)I = 2131.43 W
2131.43 W
= 19.38 A
I=
110 V
Pi =
Po
=
(15 hp)(746 W/hp)
= 12,433.33 W
0.9
12, 433.33 W
I = Pi =
= 56.52 A
E
220 V
56.
Pi =
57.
T = 1 2
=
0.75 = 0.85 2
2 = 0.88
58.
T = 1 2 = (0.87)(0.75) = 0.6525 65.25%
59.
T = 1 2 = 0.78 = 0.92
2 =
30
0.78
= 0.867 86.7%
0.9
Chapter 4
60.
61.
a.
T = 1 2 3 = (0.93)(0.87)(0.21) = 0.170 17%
b.
T = 1 2 3 = (0.93)(0.87)(0.80) = 0.647 64.7%
64.7% 17%
100% = 280.59%
17%
T =
Po
= 1 2 = 1 21 = 212
Pi
12
Po
1 =
2 Pi
Po
128 W
= 0.4
2 Pi
2(400 W)
2 = 21 = 2(0.4) = 0.8
2 = 40%, 2 = 80%
Chapter 4
31
Chapter 5
1.
a.
b.
c.
d.
e.
f.
E and R1
R1 and R2
E1, E2, and R1
E1 and R1; E2, R3 and R4
R3, R4 and R5; E and R1
R2 and R3
2.
a.
b.
c.
d.
RT = 0.1 k + 0.39 k + 1.2 k + 6.8 kΩ = 8.49 k
RT = 1.2 + 2.7 + 8.2 = 12.1
RT = 8.2 k + 10 k + 9.1 k + 1.8 k + 2.7 k = 31.8 k
RT = 47 + 820 + 91 + 1.2 k = 2158.0
3.
a.
b.
RT = 1.2 k + 1 k + 2.2 k + 3.3 k = 7.7 k
RT = 1 k + 2 k + 3 k + 4.7 k + 6.8 k = 17.5 k
4.
a.
b.
c.
1 M
100 , 1 k
RT = 100 + 1 k + 1 M + 200 k = 1.2011 M vs. 1.2 M for part b.
5.
a.
b.
RT = 10 + 33 + 56 Ω, Reading = 99
RT = 2.2 k + 0.82 kΩ + 1.2 k + 3.3 k, Reading = 7.52 k
6.
a.
b.
RT = 129 k = R + 56 k + 22 k + 33 k, Reading = 18 k
RT = 103 k = 24 k + R1 + 43 k + 2R1 = 67 k + 3R1, R1 = 12 k
R2 = 24 k
7.
a.
b.
c.
1.2 k
0
8.
a.
RT = 10 + 12 + 18 = 40
E 72 V
Is =
= 1.8 A
RT 40
V1 = I1R1 = (1.8 A)(10 ) = 18 V, V2 = I2R2 = (1.8 A)(12 ) = 21.6 V,
V3 = I3R3 = (1.8 A)(18 ) = 32.4 V
Ps = EIs = (72 V)(1.8 A) = 129.6 W
P18 = V3I3 = (32.4 V)(1.8 A) = 58.32 W
b.
c.
d.
e.
9.
a.
b.
c.
32
the most: R3, the least: R1
R3, RT = 1.2 k + 6.8 k + 82 k = 90 k
45 V
E
Is =
= 0.5 mA
RT 90 k
V1 = I1R1 = (0.5 mA)(1.2 k) = 0.6 V, V2 = I2R2 = (0.5 mA)(6.8 k) = 3.4 V,
V3 = I3R3 = (0.5 mA)(82 k) = 41 V, results agree with part (a)
Chapter 5
10.
d.
e.
Ps = EIs = (72 V)(1.8 A) = 129.6 W
P18Ω = V3I3 = (32.4 V)(1.8 A) = 58.32 W
a.
RT = 12 k + 4 k + 6 k = 22 k
E = IRT = (4 mA)(22 k) = 88 V
RT = 12 + 22 + 82 + 10 = 126
E = IRT = (500 mA)(126 ) = 63 V
b.
11.
a.
a.
b.
c.
d.
b.
a.
b.
c.
d.
12.
13.
V 5.2 V
=4A
R 1.3
E = IRT = (4 A)(9 ) = 36 V
RT = 9 = 4.7 + 1.3 + R,
V4.7 = (4 A)(4.7 ) = 18.8 V
V1.3 = (4 A)(1.3 ) = 5.2 V
V3 = (4 A)(3 ) = 12 V
I=
R=3
V
6.6 V
= 3 mA
R 2.2 k
V3.3 k = (3 mA)(3.3 k) = 9.9 V
I=
E = 6.6 V + 9 V + 9.9 V = 25.5 V
V
9V
= 3 k
R=
I 3 mA
V2.2 k = 6.6 V, V3 k = 9 V, V3.3 k = 9.9 V
1
1
36 V
E
= 8.18 mA, Vm = E (36 V) = 18 V
2
2
RT 4.4 k
a.
Im =
b.
RT = 1 k + 2.4 k + 5.6 k = 9 k
22.5 V
E
Im =
= 2.5 mA, Vm = 2.5 mA(2.4 k + 5.6 k) = 20 V
9 k
RT
c.
V3.3kΩ =
a.
RT = 3 k + 1 k + 2 k = 6 k
E 120 V
= 20 mA
Is =
6 k
RT
VR1 = (20 mA)(3 k) = 60 V
3.3 k(12 V)
= 8.8 V
4.5 k
Vm = 12 V 8.8 V = 3.2 V
12 V
Im =
= 2.67 mA
4.5 k
VR2 = (20 mA)(1 k) = 20 V
VR3 = (20 mA)(2 k) = 40 V
Chapter 5
33
b.
PR1 = I12 R1 = (20 mA)2 3 k = 1.2 W
PR2 = I 22 R2 = (20 mA)2 1 k = 0.4 W
PR3 = I 32 R3 = (20 mA)2 2 k = 0.8 W
c.
PT = PR1 PR2 PR3 = 1.2 W + 0.4 W + 0.8 W = 2.4 W
d.
PT = EIs = (120 V)(20 mA) = 2.4 W
e.
the same
f.
R1 the largest
g.
dissipated
h.
R1: 2 W, R2 : 1/2 W, R3: 1 W
14.
P = 21 W = (1 A)2R, R = 21
V1 = I1R1 = (1 A)(2 ) = 2 V, V2 = I2R2 = (1 A)(1 ) = 1 V
V3 = I3R3 = (1 A)(21 ) = 21 V
E = V1 + V2 + V3 = 2 V + 1 V + 21 V = 24 V
15
P = 8 W = I21 , I = 8 = 2.828 A
P = 16 W = I2R1 = (2 .828 A)2R1, R1 = 2
RT = 32 = 2 + R2 + 1 = 3 + R2, R2 = 29
E = IRT = (2.828 A)(32 ) = 90.5 V
16.
a.
34
1
RT = NR1 = 8 28 = 225
8
120 V
E
= 0.53 A
I=
RT 225
2
b.
8
P = I 2R = A
15
c.
8 225
V = IR = A
= 15 V
15 8
d.
All go out!
1 64 225
28
=8W
8 225 8
Chapter 5
17.
Ps = PR1 PR2 PR3
EI = I2R1 + I2R2 + 24
(R1 + R2)I2 EI + 24 = 0
6I2 24 I + 24 = 0
I2 4 I + 4 = 0
(4) (4) 2 4(1)(4) 4 16 16 4
=2A
2(1)
2
2
24
=6
P = 24 W = (2 A)2R, R =
4
I=
18.
a.
b.
c.
Vab + 4 V + 24 V 12 V = 0, Vab = 28 V + 12 V = 16 V
Vab + 4 V + 8 V 16 V = 0, Vab = 16 V 12 V = 4 V
Vab + 12 V 18 V + 6 V 12 V = 0, Vab = 30 V 18 V = 12 V
19.
a.
ET = 8 V 16 V + 20 V = 12 V, I =
b.
20.
a.
12 V
= 1.17 A
10.3
2V
= 173.91 mA
ET = 4 V + 18 V 12 V = 2 V, I
11.5
P = 8 mW = I2R, R =
I=
21.
22.
8 mW
8 mW
= 2 k
2
(2 mA)2
I
E
20 V E
= 2 mA (CW),
RT 3 k 2 k
16 V
V
12 V
= 8 mA, R =
= 1.5 k
2 k
I 8 mA
E
E 4 V 10 V E 14 V
= 8 mA (CCW)
I=
RT
2 k 1 .5 k
3.5 k
E = 42 V
b.
I=
a.
+10 V + 4 V 12 V V = 0
V = 14 V 12 V = 2 V
b.
+30 V + 20 V 8 V V = 0
V = 50 V 8 V = 42 V
c.
6 V 22 V V1 + 36 V = 0
V = 36 V 28 V = 8 V
a.
I=
b.
V2 = IR = (1.5 A)(2 Ω) = 3 V
c.
Chapter 5
E = 10 V
12 V
= 1.5 A
8
60 V 12 V V1 3 V = 0
V1 = 60 V 15 V = 45 V
35
23.
a.
b.
24.
a.
b.
25.
26.
a.
b.
d.
+ 10 V V1 + 6 V 2 V 3 V = 0, V1 = 11 V
+10 V V2 3 V = 0, V2 = 7 V
10 k
V3: V2 = 10 k:1 k = 10:1
V3: V1 = 10 k:100 = 100:1
RE
(10 k)(60 V)
V3 = 3
= 54.05 V
0.1 k 1 k 10 k
RT
( R R3 ) E (1 k 10 k)(60 V)
V = 2
= 59.46 V
11.1 k
RT
a.
V=
40 (30 V)
= 20 V
40 20
b.
V=
(2 k 3 k)(40 V)
(5 k)(40 V)
= 20 V
4 k 1 k 2 k 3 k
10 k
c.
36
V1.8Ω = IR = (3 A)(1.8 Ω) = 5.4 V
24 V V1 10 V 5.4 V = 0, V1 = 24 V 15.4 V = 8.6 V
V2.7Ω = IR = (3 A)(2.7 Ω) = 8.1 V
10 V 8.1 V V2 = 0
V2 = 10 V 8.1 V = 1.9 V
(50 V)(2 )
1 V 50 V
, R2 =
= 100
1V
2
R2
(100 V)(2 )
1 V 100 V
, R3 =
= 200
2
1V
R3
c.
27.
+10 V V2 = 0
V2 = 10 V
+10 V 6 V V1 = 0
V1 = 4 V
+24 V 10 V V1 = 0
V1 = 14 V
+10 V V2 + 8 V = 0
V2 = 18 V
(1.5 0.6 0.9 )(0.72 V)
(3 )(0.72 V)
= 0.36 V
(2.5 1.5 0.6 0.9 0.5 )
6 k
Chapter 5
28.
a.
V1
20 V
(1.2 )(20 V)
= 12 V
, V1 =
1.2 2
2
V2
20 V
(6.8 )(20 V)
, V2 =
= 68 V
6.8 2
2
E = V1 + 20 V + V2 = 12 V + 20 V + 68 V = 100 V
b.
c.
d.
29.
120 V V1 80 V = 0, V1 = 40 V
80 V 10 V V3 = 0, V3 = 70 V
V
1000 V
68 (1000 V)
= 680 V
2 , V2 =
100 68
100
1000 V V1
2 (1000 V)
= 20 V
, V1 =
100 2
100
E = V1 + V2 + 1000 V
= 20 V + 680 V + 1000 V
= 1700 V
V1 = 0 V
10 k(50 V 30 V)
V2 =
10 k 3.3 k 4.7 k
10 k(20 V)
= 11.11 V
=
18 k
Vx = E1 V3.3kΩ
3.3 k(20 V)
V3.3kΩ =
18 k
= 3.67 V
Vx = 50 V 3.67 V = 46.33 V
2V
V
2 k(2 V)
2 , V2 =
=4V
1 k 2 k
1 k
2V
V
3 k(2 V)
4 , V4 =
=6V
1 k 3 k
1 k
2V
= 2 mA
1 k
E = 2 V + 4 V + 12 V + 6 V = 24 V
I=
Chapter 5
37
30.
a.
b.
31.
a.
b.
32.
R (20 V)
2.2 k 1.8 k R
4(4 kΩ + R) = 20R
16 kΩ + 4R = 20R
16R = 16 kΩ
16
R=
k = 1 kΩ
16
4V=
(6 M R )(140 V)
6 M R 3 M
100(9 MΩ + R) = 840 MΩ + 140R
900 MΩ + 100R = 840 MΩ + 140R
40R = 60 MΩ
60
R=
M = 1.5 MΩ
40
100 V =
8V
= 160
50 mA
R (12 V) 160 (12 V)
, Rx = 80 in series with the bulb
Vbulb = 8 V = bulb
160 Rx
Rbulb Rx
Rbulb =
VR = 12 V 8 V = 4 V, P =
V 2 (4 V) 2
= 0.2 W, 1/4 W okay
R
80
VR1 VR2 = 72 V
1
VR VR2 = 72 V
5 2
72 V
1
= 60 V
VR2 1 = 72 V, VR2
1.2
5
VR
VR
60 V
72 V 60 V 12 V
R2 = 2
= 15 k, R1 = 1
= 3 k
I R2
I R1
4 mA
4 mA
4 mA
33.
RT = R1 + R2 + R3 = 2R3 + 7R3 + R3 = 10R3
R (60 V)
VR3 = 3
= 6 V, VR1 = 2VR3 = 2 (6 V) = 12 V, VR2 7VR3 = 7(6 V) = 42 V
10 R3
34.
a.
VR3 4VR2 = 4(3VR1 ) 12VR1
E = VR1 3VR1 12VR1 RT = R1 + 3R1 + 12R1 = 16R1 =
R1 =
38
64 V
= 6.4 k
10 mA
6.4 k
= 400 , R2 = 3R1 = 1.2 k, R3 = 12R1 = 4.8 k
16
Chapter 5
35.
36.
6.4 M
64 V
= 400 k, R2 = 1.2 M, R3 = 4.8 M
= 6.4 M, R1 =
10 A
16
I1 10 mA
R 400 k
= 103 also
= 103 and 1
I 10 A
R1
400
b.
RT =
a.
Va = 12 V + 5 V = 17 V
Vb = 5 V + 16 V = 21 V
Vab = 17 V 21 V = 4 V
b.
Va = 14 V
Vb = 14 V + 6 V + 10 V = 30 V
Vab = 14 V 30 V = 16 V
c.
Va = 10 V + 3 V = 13 V
Vb = 8 V
Vab = 13 V (8 V) = 21 V
a.
60 V + 20 V 80 V
= 0.8 A
18 82 100
Va = 60 V I(18 Ω) = 60 V (0.8 A)(18 Ω) = 60 V 14.4 V = 45.6 V
I =
I =
100 V + 60 V
160 V
= 20 mA
2 k 2 k 2 k 2 k 8 k
Va = 10 V I(2 kΩ) = 100 V (20 mA)(2 kΩ) = 100 V 40 V = 60 V
37.
38.
47 V 20 V
27 V
=
= 3 mA (CCW)
2k +3k + 4k 9k
V2k = 6 V, V3k = 9 V, V4k = 12 V
I=
a.
Va = 20 V, Vb = 20 V + 6 V = 26 V, Vc = 20 V + 6 V + 9 V = 35 V
Vd = 12 V, Ve = 0 V
b.
Vab = 6 V, Vdc = 47 V, Vcb = 9 V
c.
Vac = 15 V, Vdb = 47 V + 9 V = 38 V
VR
4 V + 4 V 8V
12 V 4 V 8 V
= 1 A, R1 = 1 =
= 8 Ω,
8
8
I
1A
1A
VR
8V 4V 4V
=4Ω
R3 = 3 =
I
1A
1A
I R2 =
Chapter 5
39
39.
VR2 = 48 V 12 V = 36 V
VR3
=
VR3
12 V
= 0.75 k
=
I
16 mA
= 20 V
R3 =
VR4
VR2
36 V
= 2.25 k
I
16 mA
= 12 V 0 V = 12 V
R2 =
VR4
20 V
= 1.25 k
I
16 mA
VR1 E VR2 VR3 VR4
R4 =
=
= 100 V 36 V 12 V 20 V = 32 V
VR
32 V
= 2 k
R1 = 1 =
I
16 mA
40.
41.
42.
40
a.
Va = 8 V + 14 V = +6 V, Vb = 14 V
Vc = +I(10 Ω) 6 V with
14 V + 6 V 20 V
=1A
I=
10 10 20
Therefore, Vc = (1 A)(10 Ω) 6 V = 10 V 6 V = 4 V
Vd = 0 V
b.
Vab = Va Vb = 6 V 14 V = 8 V
Vcb= Vc Vb = 4 V 14 V = 10 V
Vcd = Vc Vd = 4 V 0 V = 4 V
c.
Vad = Va Vd = 6 V 0 V = 6 V
Vca = Vc Va = 4 V 6 V = 2 V
V0 = 0 V, V4 = (2 kΩ)(6 mA) + 3 V = 12 V + 3 V = 15 V, V7 = 4 V
V10 = V1 V0 = 12 V 0 V = 12 V, V23 = V2 V3 = 4 V (8 V) = 4 V + 8 V = 12 V
V30 = V3 V0 = 8 V 0 V = 8 V, V67 = V6 V7 = 4 V 4 V = 0 V
4 V + 8 V 12 V
=3A
V56 = V5 V6 = 3 V 4 V = 1 V, I =
4
4
V0 = 0 V, V03 = V0 V3 = 0 V 0 V = 0 V, V2 = (3 mA)(3.3 kΩ) = 9.9 V
V23 = V2 V3 = 9.9 V 0 V = 9.9 V, V12 = V1 V2 = 20 V 9.9 V = 10.1 V
Ii Io
Ii = 4 mA + 3 mA + 10 mA = 17 mA
Chapter 5
43.
44.
45.
a.
VL = ILRL = (2 A)(28 ) = 56 V
Vint = 60 V 56 V = 4 V
V
4V
=2
Rint = int
I
2A
b.
VR =
60 V 56 V
VNL VFL
100% = 7.14%
100% =
VFL
56 V
a.
VL =
3.3 (12 V)
39.6 V
= 11.85 V
3.3 43 m 3.343
b.
VR =
12 V 11.85 V
VNL VFL
100% = 1.27%
100% =
11.85 V
VFL
c.
Is = IL =
a.
I=
E
12 V
12 V
= 1.36 mA
RT 2 k 6.8 k 8.8 k
b.
I=
E
12 V
12 V
= 1.33 mA
RT 8.8 k 0.25 k 9.05 k
c.
not for most applications.
Chapter 5
11.85 V
= 3.59 A
3.3
Ps = EIs = (12 V)(3.59 A) = 43.08 W
Pint = I2Rint = (3.59 A)2 43 = 0.554 W
41
Chapter 6
1.
a.
b.
c.
d.
e.
f.
g.
R2 and R3
E and R3
R2 and R3
R2 and R3
E, R1, R2, R3, and R4
E, R1, R2, and R3
E2, R2 and R3
2.
a.
b.
R3 and R4, R5 and R6
E and R1, R6 and R7
3.
a.
RT =
b.
RT =
c.
RT =
d.
e.
4.
42
(36 )(18 )
= 12
36 18
1
1
3
1
1
1
1 10 S 0.5 103 S 33.33 106 S
1 k 2 k 30 k
1
=
= 0.652 k
1.533 103 S
1
1
1
6
3
3
1
1
1
833.33 10 S 8.33 10 S 83.33 10 S 92.49 103 S
1.2 120 k 12 k
= 10.81
18 k
= 6 k
3
(6 k)(6 k)
= 3 k
RT =
6 k 6 k
RT =
22
10
= 5.5 , RT =
=5
4
2
(5.5 )(5 )
= 2.62
RT =
5.5 5
RT =
1
1
3
1
1
1
1000 10 S 1 10 3 S 0.001 103 S
1 1 k 1 M
1
=
= 0.99
1001.001 10 3 S
f.
RT =
a.
RT =
1
1
3
1
1
1
1 10 S 0.833 103 S 3.333 10 3 S
1 k 1 .2 k 0 .3 k
1
=
= 193.57
5.166 10 3 S
Chapter 6
5.
1
1
1 10 S 0.833 10 S 0.455 10 3 S 1 103 S
b.
RT =
a.
RT = 3 6 = 2
(2 )( R )
, R=8
RT = 1.6 =
2R
6 k
= 2 k
RT =
3
(2 k)( R)
, R = 18 k
RT = 1.8 k =
2 k R
(20 k)( R )
, R = 6.8 k
RT = 5.08 k =
20 k R
1
1
RT = 1.02 =
1
1
1
1
416.67 10 6 S + 147.06 10 6 S
2.4 k R 6.8 k
R
1
1.02 kΩ =
1
563.73 106
R
1.020
k
=1
575 × 103 +
R
1.020 k
R=
= 2.4 kΩ
425 103
b.
c.
d.
e.
1
1
1
1
1 k 1.2 k 2.2 k 1 k
1
= 304.14
=
3.288 103 S
RT = 6 kΩ =
3
3
R1
4
R1 = 24 kΩ
6.
a.
b.
1.2 k
about 1 k
c.
RT =
d.
e.
Chapter 6
1
1
1
1
1
1.2 k 22 k 220 k 2.2 M
1
=
6
6
833.333 10 S 45.455 10 S 4.545 10 6 S 0.455 10 6 S
1
= 1.131 k
=
883.788 10 6 S
(1.2 k)(22 k)
220 k, 2.2 M: RT =
= 1.138 k
1.2 k 22 k
RT reduced.
43
7.
1
1
1
= 1.18
1
1
1
0.25 S + 0.50 S 0.10 S 0.85 S
4 2 10
a.
RT =
b.
c.
RT = 3 Ω 6 Ω = 2
8.
24 24 = 12
1
1
1
1
RT R1 12 120
1
+ 0.08333 S + 0.00833 S
0.1 S =
R1
1
+ 0.09167 S
0.1 S =
R1
1
= 0.1 S 0.09167 S = 0.00833 S
R1
1
= 120
R1 =
0.00833 S
9.
a.
RT =
b.
VR1 VR2 = 36 V
c.
Is =
d.
Is = I1 + I2
6 A = 4.5 A + 1.5 A = 6 A (checks)
a.
I1 =
b.
RT =
c.
Is =
10.
44
(8 )(24 )
=6
8 24
E 36 V
=6A
6
RT
VR 36 V
= 4.5 A
I1 1
8
R1
VR
36 V
= 1.5 A
I2 2
R2 24
VR1
R1
VR 18 V
VR 18 V
18 V
= 0.5 A
= 6 A, I2 = 2
= 2 A, I3 = 3
3
9
R3 36
R2
1
1
1
1
1
0
.
333
S
0
.
111
S 0.028 S
3 9 36
1
= 2.12
=
472 103 S
E
18 V
= 8.5 A
RT 2.12
Chapter 6
11.
d.
Is = I1 + I2 + I3 = 6 A + 2 A + 0.5 A = 8.5 A
e.
they match
a.
I R1
I R3
12.
VR1
R1
VR3
R3
VR
24 V
24 V
= 2.4 mA, I R2 2
= 20 mA,
10 k
R 2 1.2 k
24 V
= 3.53 mA
6.8 k
1
1
6
1
1
1
100 10 S 833.333 106 S 147.06 106 S
10 k 1.2 k 6.8 k
1
= 925.93
=
1.08 103 S
b.
RT =
c.
Is =
d.
Is = I1 + I2 + I3 = 2.4 mA + 20 mA + 3.53 mA = 25.93 mA
e.
they match
a.
RT 900
b.
RT =
c.
I3 the most, I4 the least
d.
I R1
24 V
E
= 25.92 mA
RT 925.93
1
1
1
1
1
20 k 10 k 1 k 91 k
1
=
6
6
50 10 S 100 10 S 1 103 S 10.99 106 S
1
=
= 862.07 , very close
1.16 103 S
I R3
VR1
VR
60 V
60 V
= 3.0 mA, I R2 2
= 6 mA
R1 20 k
R2 10 k
VR
VR
60 V
60 V
= 60.0 mA, I R4 4
= 0.659 mA
3
R3 1 k
R4 91 k
60 V
E
= 69.6 mA
RT 862.07 k
Is = 3 mA + 6 mA + 60 mA + 0.659 mA = 69.66 mA (checks)
e.
Is =
f.
always greater
Chapter 6
45
13.
14.
RT = 6 Ω =
b.
P = 81 W =
a.
P=
b.
R2 =
c.
I1 =
d.
Is = I1 + I2 + I3 = 2 A + 2 A +
e.
Ps = EIs = (20 V)(9 A) = 180 W
f.
g.
15.
(18 )( R2 )
18 R2
108 Ω + 6R2 = 18R2
12R2 = 108 Ω
108
=9Ω
R2 =
12
a.
V 2 E2 E2
R
R 9
and E2 = (9)(81)
or E = 729 = 27 V
V 2 E2
and E =
R
R
PR (100 W)(4 ) 400 = 20 V
E 20 V
= 10 Ω
I2
2A
V1 E 20 V
=2A
R1 R1 10
20 V
=4A+5A=9A
4
E 2 (20 V) 2 400 W
E 2 (20 V) 2
= 40 W, PR2
= 40 W,
PR1
10
R2 20 V
R1
10
2A
Ps = P1 + P2 + P3
180 W = 40 W + 40 W + 100 W = 180 W (checks)
(20 )(10.8 A)
=9A
20 4
E = VR3 I 3 R3 (9 A)(4 ) = 36 V
I3 =
I R1 = 12.3 A 10.8 A = 1.5 A
R1 =
16.
46
VR1
I R1
36 V
= 24
1.5 A
a.
V = 48 V
b.
I2 =
48 V
= 2.67 mA
18 k
Chapter 6
17.
c.
Is =
48 V 48 V
I 2 = 16 mA + 4 mA + 2.67 mA = 22.67 mA
3 k 12 k
d.
P=
V 2 E 2 (48 V)2
= 192 mW
R
R
12 k
a.
I R2 = 4 A 1 A = 3 A, R2 =
b.
R3 =
c.
I1
18.
19.
a.
VR3
I2
E 12 V
=4Ω
I2 3 A
E 12 V
= 12 Ω
I3 1 A
12 V
= 6 A, Is = I1 + 4 A = 6 A + 4 A = 10 A
2
1
1
6
1
1
1
1000 10 S 212.77 106 S 100 106 S
1 k 4.7 k 10 k
1
=
= 761.61
1.313 103 S
VR 60 V
VR
60 V
= 60 mA, I R2 2
= 12.77 mA
I R1 1
R1 1 k
R2 4.7 k
RT =
I R3
b.
I3
VR2
VR3
R3
60 V
= 6 mA
10 k
PR1 VR1 I R1 = (60 V)(60 mA) = 3.6 W
PR2 VR2 I R2 = (60 V)(12.77 mA) = 766.2 mW
PR3 VR3 I R3 = (60 V)(6 mA) = 360 W
c.
d.
e.
20.
a.
b.
c.
Chapter 6
E
60 V
= 78.78 mA
RT 761.61
Ps = EsIs = (60 V)(78.78 mA) = 4.73 W
Ps = 4.73 W = 3.6 W + 766.2 mW + 360 mW = 4.73 W (checks)
R1 = the smallest parallel resistor
Is =
120 V
E
= 66.667 mA
Rbulb 1.8 k
R 1.8 k
RT =
= 225
N
8
E 120 V
= 0.533 A
Is =
RT 225
Ibulb =
47
21.
V 2 (120 V)2
=8W
R
1.8 k
d.
P=
e.
Ps = 8(8 W) = 64 W
f.
none, Is drops by 66.667 mA
Network redrawn:
RT = 3.33 Ω 7.5 Ω = 2.31 Ω
E 2 (60 V)2
= 1.56 kW
Ps =
RT
2.31
22.
48
a.
5 × 60 W = 300 W
300 W
= 2.5 A
Ibulbs =
120 V
1200 W
Imicro =
= 10 A
120 V
320 W
ITV =
= 2.67 A
120 V
25 W
= 208.33 mA
IDVD =
120 V
b.
Is = I = 2.5 A + 10 A + 2.67 A + 208.33 mA = 15.38 A
No
c.
RT =
d.
Ps = E Is = (120 V)(15.38 A) = 1,845.60 W
e.
Ps = 1845.60 W = 300 W + 1200 W + 320 W + 25 W = 1845 W (checks)
E
120 V
= 7.8 Ω
I s 15.38 A
Chapter 6
23.
a.
b.
c.
8 12 = 4.8 , 4.8 4 = 2.182
24 V 8 V
= 14.67 A
I1 =
2.182
V 2 (24 V 8 V) 2
P4 =
= 256 W
R
4
I2 = I1 = 14.67 A
24.
Is = 8 mA + 6 mA = 14 mA
I2 = 6 mA 2 mA = 4 mA
25.
a.
Ii Io
2A+3A+9A=6A+I
14 A = 6 A + I
I = 14 A 6 A = 8 A
b.
Ii Io
8 mA = 2 mA + I1
I1 = 8 mA 2 m A = 6 mA
Ii Io
I1 + 9 mA = I2
I2 = 6 mA + 9 mA = 15 mA
Ii Io
I2 = 10 mA + I3
I3 = 15 mA 10 mA = 5 mA
a.
Ii Io
8 A = 3 A + I2
I2 = 8 A 3 A = 5 A, I3 = 3 A
Ii Io
I2 + I3 = I4
I4 = 5 A + 3 A = 8 A
b.
Ii Io
Is = 36 mA + 4 mA = 40 mA
Ii Io
36 mA = I3 + 20 mA
I3 = 36 mA 20 mA = 16 mA
Ii Io
4 mA + 20 mA = I4
I4 = 24 mA
I5 = Is = 40 mA
26.
Chapter 6
49
27.
I R2 = 5 mA 2 mA = 3 mA
E = VR2 = (3 mA)(4 k) = 12 V
R1 =
R3 =
28.
VR1
I R1
VR3
I R3
12 V
12 V
= 3 k
(9 mA 5 mA) 4 mA
12 V
= 6 k
2 mA
RT =
12 V
E
= 1.33 k
I T 9 mA
a.
R1 =
b.
E = I1R1 = (2 A)(6 ) = 12 V
E 12 V
= 1.33 A
I2 =
9
R2
E 10 V
=5
I1 2 A
I2 = I I1 = 3 A 2 A = 1 A
E 10 V
= 10
R=
1A
I2
P 12 W
=1A
V 12 V
E 12 V
= 12
R3 =
1A
I3
I = I1 + I2 + I3 = 2 A + 1.33A + 1 A = 4.33 A
I3 =
29.
50
a.
64 V
= 64 mA
1 k
64 V
I3 =
= 16 mA
4 k
Is = I1 + I2 + I3
I2 = Is I1 I3 = 100 mA 64 mA 16 mA = 20 mA
64 V
E
R=
= 3.2 k
I 2 20 mA
I = I2 + I3 = 20 mA + 16 mA = 36 mA
I1 =
Chapter 6
b.
V12
V1 PR1 (30 W)(30 ) = 30 V
R1
E = V1 = 30 V
E 30 V
=1A
I1 =
R1 30
Because R3 = R2, I3 = I2 , and Is = I1 + I2 + I3 = I1 + 2I2
2 A = 1 A + 2I2
1
I2 = (1 A) = 0.5 A
2
I3 = 0.5 A
E 30 V
= 60
R2 = R3 =
I 2 0.5 A
P=
PR2 I 22 R2 = (0.5 A)2 60 = 15 W
30.
31.
32.
6
1
1
I1 I1 = (9 A) = 4.5 A
12
2
2
6
I3 =
I1 3I1 = 3(9 A) = 27 A
2
6
1
1
I4 =
I1 I1 = (9 A) = 3 A
18
3
3
IT = I1 + I2 + I3 + I4 = 9 A + 4.5 A + 27 A + 3 A = 43.5 A
I2 =
8 k(20 mA )
= 16 mA
2 k 8 k
I2 = 20 mA 16 mA = 4 mA
a.
I1 =
b.
I2.4kΩ = 2.5 A =
a.
1 k( IT )
1 k( IT )
1 k 2.4 k
3.4 k
3.4 k(2.5 A)
and IT =
= 8.5 A
1 k
I1 = IT 2.5 A = 8.5 A 2.5 A = 6 A
1
1
=
3
1
1
1
250 10 S 125 103 S 83.333 10 3 S
4 8 12
1
=
= 2.18
458.333 103
R
2.18
(6 A) = 3.27 A
I1 =
Ix = T I,
4
Rx
RT =
2.18
(6 A) = 1.64 A
8
2.18
I3 =
(6 A) = 1.09 A
12
I4 = 6 A
I2 =
Chapter 6
51
b.
33.
9
(10 A) = 9 A
10
a.
I1
b.
I1/I2 = 10 /1 = 10,
c.
I1/I3 = 1 k/1 = 1000, I3 = I1/1000 = 9 A/1000 9 mA
d.
I1/I4 = 100 k/1 = 100,000, I4 = I1/100,000 = 9 A/100,000 90 A
e.
very little effect, 1/100,000
1
RT =
1
1
1
1
1 10 1 k 100 k
1
=
1 S 0.1 S 1 10 3 S 10 10 6 S
1
=
= 0.91
1.10 S
R
0.91
(10 A) = 9.1 A excellent (9 A)
Ix = T I , I1 =
1
Rx
f.
I2 =
I1 9 A
0.9 A
10 10
g.
I2 =
0.91
(10 A) = 0.91 A excellent (0.9 A)
10
h.
I3 =
0.91
(10 A) = 9.1 mA excellent (9 mA)
1 k
i.
34.
4 Ω 4 Ω = 2 Ω
20 (8 A)
20 (8 A)
= 5.33 A
I2 =
20 2 8
30
I
5.33 A
I1 = 2
= 2.67 A
2
2
I3 = 8 A I2 = 8 A 5.33 A = 2.67 A
I4 = 8 A
a.
0.91
(10 A) = 91 A excellent (90 A)
100 k
3 I
(39 )(1 A)
CDR: I36 =
= 1 A, I =
= 13 A = I2
3 36
3
I4 =
I1 = I 1 A = 13 A 1 A = 12 A
b.
52
I3 = I = 24 mA, V12kΩ = IR = (4 mA)(12 kΩ) = 48 V
V 48 V
= 12 mA
I2 =
R 4 k
I1 = I 4 mA I2
= 24 mA 4 mA 12 mA
= 8 mA
Chapter 6
35.
a.
b.
36.
84 mA = I1 + I2 + I3 = I1 + 2I1 + 2I2 = I1 + 2I1 + 2(2I1)
84 mA = I1 + 2I1 + 4I1 = 7I1
84 mA
and I1 =
= 12 mA
7
I2 = 2I1 = 2(12 mA) = 24 mA
I3 = 2I2 = 2(24 mA) = 48 mA
VR
24 V
R1 = 1
= 2 k
I1 12 mA
R2 =
R3 =
37.
38.
39.
R = 3(2 k) = 6 k
6 k(32 mA)
= 24 mA
I1 =
6 k 2 k
I
24 mA
= 8 mA
I2 = 1
3
3
VR2
I2
VR3
I3
24 V
= 1 k
24 mA
24 V
= 0.5 k
48 mA
b.
c.
PL = VLIL
72 W = 12 V IL
72 W
=6A
IL =
12 V
6A
I
I1 = I2 = L
=3A
2
2
Psource = EI = (12 V)(3 A) = 36 W
Ps1 Ps2 = 36 W + 36 W = 72 W (the same)
d.
Idrain = 6 A (twice as much)
a.
RT = 8 56 = 7
E 12 V
I2 = I3 =
= 1.71 A
7
RT
1
1
I1 = I 2 (1.71 A) = 0.86 A
2
2
16 V
= 2 A, I = 5 A 2 A = 3 A
8
16 V
V
=2
IR = 5 A + 3 A = 8 A, R = R
8A
IR
I8 =
Chapter 6
53
40.
a.
b.
c.
41.
a.
b.
c.
42.
43.
4.7 k(9 V)
42.3V
= 6.13 V
4.7 k 2.2 k
6.9
VL = E = 9 V
VL = E = 9 V
VL =
b.
c.
20 V
= 5 A, I2 = 0 A
4
V1 = 0 V, V2 = 20 V
Is = I1 = 5 A
a.
V2 =
b.
RT = 11 M 22 k = 21.956 k
21.956 k(20 V)
= 16.47 V (very close to ideal)
V2 =
21.956 k 4.7 k
c.
Rm = 20 V[20,000 /V] = 400 k
RT = 400 k 22 k = 20.853 k
20.853 k(20 V)
= 16.32 V (still very close to ideal)
V2 =
20.853 k 4.7 k
d:
a.
V2 =
b.
RT = 200 k 11 M = 196.429 k
(196.429 k)(20 V)
= 13.25 V (very close to ideal)
V2 =
196.429 k 100 k
c.
Rm = 400 k
RT = 400 k 200 k = 133.333 k
(133.333 k)(20 V)
= 11.43 V (a 1.824 V drop from Rint = 11 M level)
V2 =
133.333 k 100 k
a.
e.
54
E
12 V
12 V
= 1.188 mA
RT 0.1 k 10 k 10.1 k
VL = IsRL = (1.19 mA)(10 k) = 11.90 V
12 V
= 120 mA
Is =
100
VL = E = 12 V
Is =
I1 =
22 k(20 V)
= 16.48 V
22 k 4.7 k
200 k(20 V)
= 13.33 V
200 k 100 k
DMM level of 11 M not a problem for most situations
VOM level of 400 k can be a problem for some situations.
Chapter 6
44.
a.
Vab = 20 V
b.
Vab =
c.
Rm = 200 V[20,000 /V] = 4 M
4 M(20 V)
= 16.0 V (significant drop from ideal)
Vab =
4 M 1 M
Rm = 20 V[20,000 /V] = 400 k
400 k(20 V)
= 5.71 V (significant error)
Vab =
400 k 1 M
11 M(20 V)
= 18.33 V
11 M 1 M
45.
not operating properly, 6 k not connected at both ends
6V
= 1.71 k
RT =
3.5 mA
RT = 3 k 4 k = 1.71 k
46.
Vab = E + I4 k R4 k
12 V 4 V
8V
= 1.6 mA
I4 k =
1 k 4 k 5 k
Vab = 4 V + (1.6 mA)(4 k) = 4 V + 6.4 V = 10.4 V
4 V supply connected in reverse so that
12 V 4 V 16 V
= 3.2 mA
I=
1 k 4 k 5 k
and Vab = 12 V (3.2 mA)(1 k) = 12 V 3.2 V = 8.8 V obtained
Chapter 6
55
Chapter 7
1.
a.
b.
c.
d.
e.
f.
2.
a.
b.
c.
d.
R1, R2,. and E are in series; R3, R4 and R5 are in parallel
E and R1 are in series; R2, R3 and R4 are in parallel.
E and R1 are in series; R2, R3 and R4 are in parallel.
E1 and R1 are in series; E2 and R4 in parallel.
E and R1 are in series, R2 and R3 are in parallel.
E, R1, R4 and R6 are in parallel; R2 and R5 are in parallel.
RT = 4 + 10 (4 + 4 ) + 4 = 4 Ω + 10 8 + 4
= 4 + 4.44 + 4 = 12.44
10
= 10 + 5 = 15
RT = 10 +
2
4
+ 10 = 2 + 10 = 12
RT =
2
RT = 10
3.
2.2 k 10 k = 1.8 k
RT = 2 × 1.8 kΩ = 3.6 kΩ
RT = 1 Ω (1 Ω + 1 Ω + RT) = 1 Ω (2 Ω + RT)
2 RT
2 RT
=
1 2 RT 3 RT
RT(3 Ω + RT) = 2 Ω + RT
3RT + RT2 = 2 Ω + RT
4.
RT2 + 2RT 2 Ω = 0
2 (2) 2 4(1)(2)
2
2 4 8 2 12 2 3.464
=
2
2
2
RT = 1 1.732 = 0.732 Ω or 2.732 Ω
Since RT < 1 Ω and positive choose RT = 0.732 Ω
RT =
56
Chapter 7
5.
R
RT = 7.2 kΩ = R1 R1 1 = R1 1.5R1
2
( R1 )(1.5R1 ) 1.5 R12 1.5 R1
2.5 R1
2.5
R1 1.5 R1
2.5(7.2 k)
1.2 kΩ
and R1 =
1.5
so that 7.2 kΩ =
6.
a.
b.
c.
d.
e.
f.
g.
7.
a.
b.
c.
8.
yes
I2 = Is I1 = 10 A 4 A = 6 A
yes
V3 = E V2 = 14 V 8 V = 6 V
RT = 4 2 = 1.33 , RT = 4 6 = 2.4
RT = RT RT = 1.33 + 2.4 = 3.73
20
= 10 , RT = RT RT = 10 + 10 = 20
RT RT =
2
20 V
E
=1A
Is =
RT 20
Ps = EIs = Pabsorbed = (20 V)(1 A) = 20 W
RT = R1 R2 = 10 15 = 6
RT = RT (R3 + R4) = 6 (10 + 2 ) = 6 12 = 4
E
E 36 V
36 V
=
=6A
= 9 A, I1 =
Is =
RT
4
6
RT
36 V
36 V
E
=3A
I2 =
R3 R4 10 2 12
I1 = Is I2 = 6 A 3 A = 3 A
Va = I2R4 = (3 A)(2 ) = 6 V
Redrawn:
a.
b.
Va = 32 V
8 Ω 24 Ω = 6 Ω
6 (32 V)
= 10.67 V
Vb =
6 12
32 V
32 V
= 1.78 A
12 +6 18
RT = 72 Ω 18 Ω 18 Ω = 8.12 Ω
I1 =
9Ω
Chapter 7
57
Is =
9.
a.
b.
32 V
E
= 3.94 A
RT 8.12
Va = 36 V, Vb = 60 V Vc =
5 k(60 V)
= 20 V
5 k 10 k
60 V 36 V
= 24 mA,
I1
1 k
60 V
60 V
I8kΩ = 8 k = 7.5 mA, I10kΩ =
= 4 mA
15 k
24 mA
I 24 mA + 7.5 mA = 31.5 mA
I 2 31.5 mA + 4 mA = 35.5 mA
10.
11.
a.
RT = 1.2 k + 6.8 k = 8 k, RT = 2 k RT = 2 k 8 k = 1.6 k
RT = RT + 2.4 k = 1.6 k + 2.4 k = 4 k
RT = 1 k RT = 1 k 4 k = 0.8 k
b.
Is =
48 V
E
= 60 mA
RT 0.8 k
c.
V=
(1.6 k)(48 V)
RTE
= 19.2 V
RT 2.4 k 1.6 k 2.4 k
RT = 2 R 2 R (R + R) = 2 R 2R 2 R =
2R
3
E 120 V
= 15 Ω
I
8A
2R
3
15 Ω =
and R = (15 ) = 22.5 Ω
3
2
2 R = 45 Ω
RT =
12.
58
a.
RT = (R1 R2 R3) (R6 + R4 R5)
= (12 k 12 k 3 k) (10.4 k + 9 k 6 k)
= (6 k 3 k) (10.4 k + 3.6 k)
= 2 k 14 k = 1.75 k
28 V
28 V
E
E
= 16 mA, I2 =
= 2.33 mA
Is =
RT 1.75 k
R2 12 k
R = R1 R2 R3 = 2 k
R = R6 + R4 R5 = 14 k
Chapter 7
I6 =
Chapter 7
2 k(16 mA)
R( I s )
= 2 mA
R R 2 k 14 k
59
b.
V1 = E = 28 V
R = R4 R5 = 6 k 9 k = 3.6 k
V5 = I6 R = (2 mA)(3.6 k) = 7.2 V
VR23
c.
P=
13.
a.
I1
14.
I1 =
15.
a.
60
(28 V)2
= 261.33 mW
3 k
24 V
= 6 A; VR2 24 V 8 V = 16 V, I 2 VR2 / R2 = 16 V/2 Ω = 8 A
4
8V
I 3
= 0.8 A, I = I1 + I2 = 6 A + 8 A = 14 A
10
20 V
= 425.5 mA
47
14 V
14 V
I2 =
= 139.35 mA
160 270 100.47
b.
16.
R3
a.
R = R4 + R5 = 14 Ω + 6 Ω = 20 Ω
R = R2 R = 20 Ω 20 Ω = 10 Ω
R = R + R1 = 10 Ω + 10 Ω = 20 Ω
RT = R3 R = 5 Ω 20 Ω = 4 Ω
E 20 V
=5A
=
Is =
RT 4
20 V
20 V
20 V
=1A
I1 =
=
=
R1 R 10 + 10 20
20 V
=4A
I3 =
5
I
1A
I4 = 1 = (since R = R2) =
= 0.5 A
2
2
Va = I3R3 I4R5 = (4 A)(5 Ω) (0.5 A)(6 Ω) = 20 V 3 V = 17 V
I
Vbc = 1 R2 = (0.5 A)(20 Ω) = 10 V
2
20 V
E
R1 R4 ( R2 R3 R5 ) 3 3 (3 6 6 )
20 V
20 V
20 V
=
=
=
3 + 3 (3 + 3 ) 3 + 3 6 3 + 2
=4A
I1 =
Chapter 7
17.
R4 ( I1 )
3 (4 A)
R4 R2 R3 R5 3 3 6 6
12 A
= 1.33 A
=
6+3
I
I3 = 2 = 0.67 A
2
b.
CDR: I2 =
c.
I4 = I1 I2 = 4 A 1.33 A = 2.67 A
Va = I4R4 = (2.67 A)(3 Ω) = 8 V
Vb = I3R3 = (0.67 A)(6 Ω) = 4 V
a.
IE =
b.
IB =
c.
VB = VBE + VE = 2.7 V
VC = VCC ICRC = 8 V (2 mA)(2.2 kΩ) = 8 V 4.4 V = 3.6 V
d.
VCE = VC VE = 3.6 V 2 V = 1.6 V
VE
2V
= 2 mA
RE 1 k
IC = IE = 2 mA
VCC (VBE VE ) 8 V (0.7 V + 2 V)
=
RB
RB
220 k
8 V 2.7 V
5.3 V
=
=
= 24 μA
220 k
220 k
VRB
=
VBC = VB VC = 2.7 V 3.6 V = 0.9 V
18.
19.
22 V
22 V
=1A
4 18 22
a.
I=
b.
22 V + Vi 22 V = 0, V1 = 44 V
a.
All resistors in parallel (between terminals a & b)
RT = 16 Ω 16 Ω 8 Ω 4 Ω 32 Ω
8 Ω 8 Ω 4 Ω 32 Ω
4 Ω 4 Ω 32 Ω
2 Ω 32 Ω = 1.88
Chapter 7
61
b.
All in parallel. Therefore, V1 = V4 = E = 32 V
c.
I3 = V3/R3 = 32 V/4 Ω = 8 A
d.
12 V
= 1.2 mA
10 k
V ab = Va Vb = 12 V (18 V) = 30 V
20.
I=
21.
a.
b.
22.
Is = I1 + I2 + I3 + I4 + I5
32 V 32 V 32 V 32 V 32 V
+
+
+
+
=
16 8
4 32 16
=2A+4A+8A+1A+2A
= 17 A
E 32 V
RT =
= 1.88 Ω as above
=
I s 17 A
a.
Va = 6 V, Vb = 20 V
Vab = Va Vb = (6 V) (20 V) = 6 V + 20 V = +14 V
20 V
=4A
5
V
14 V
I 2 ab
=7A
2 2
6V
I 3
=2A
3
I3Ω = I2Ω + I 6V , I6V = I3Ω I2Ω = 2 A 7 A = 5 A
I + I6V = I5Ω, I = I5Ω I6V = 4 A (5A) = 9 A
I 5
Applying Kirchoff's voltage law in the CCW direction in the upper "window":
+18 V + 20 V V8Ω = 0
V8Ω = 38 V
38 V
= 4.75 A
8
18 V
18 V
=2A
I3Ω =
=
3 + 6 9
I8Ω =
KCL: I18V = 4.75 A + 2 A = 6.75 A
b.
62
V = (I3Ω)(6 Ω) + 20 V = (2 A)(6 Ω) + 20 V = 12 V + 20 V = 32 V
Chapter 7
23.
I2R2 = I3R3 and I2 =
I1 = I2 + I3 =
I 3 R3 2 R3 R3
(since the voltage across parallel elements is the same)
20 10
R2
R3
+2
10
R
KVL: 120 = I112 + I3R3 = 3 2 12 + 2R3
10
and 120 = 1.2R3 + 24 + 2R3
3.2R3 = 96
96
= 30
R3 =
3.2
24.
Assuming Is = 1 A, the current Is will divide as determined by the load appearing in each
branch. Since balanced Is will split equally between all three branches.
10
1
V1 = A (10 ) = V
3
3
10
1
V2 = A (10 ) = V
6
6
10
1
V3 = A (10 ) = V
3
3
10
10
10
E = V1 + V2 + V3 =
V + V + V = 8.33 V
3
6
3
E 8.33 V
= 8.33
RT = =
I
1A
25.
36 kΩ 6 kΩ 12 kΩ = 3.6 kΩ
3.6 k (45 V)
V=
= 16.88 V 27 V. Therefore, not operating properly!
3.6 k + 6 k
6 kΩ resistor "open"
R (45V)
9 k(45 V)
= 27 V
R = 12 k 36 k = 9 k, V =
R 6 k 9 k 6 k
Chapter 7
63
26.
a.
RT = R5 (R6 + R7) = 6 3 = 2
RT = R3 (R4 + RT) = 4 (2 + 2 ) = 2
RT = R1 + R2 + RT = 3 + 5 + 2 = 10
240 V
= 24 A
I=
10
b.
I4 =
c.
d.
27.
28.
a.
4 ( I )
4 (24 A)
= 12 A
44
8
6 (12 A) 72 A
=8A
I7 =
6 3
9
V3 = I3R3 = (I I4)R3 = (24 A 12 A)4 Ω = 48 V
V5 = I5R5 = (I4 I7)R5 = (4 A)6 Ω = 24 V
V7 = I7R7 = (8 A)2 Ω = 16 V
P = I 72 R7 = (8 A)22 Ω = 128 W
P = EI = (240 V)(24 A) = 5760 W
RT = R4 (R6 + R7 + R8) = 2 Ω 7 Ω = 1.56 Ω
RT = R2 (R3 + R5 + RT) = 2 Ω (4 Ω + 1 Ω + 1.56 Ω) = 1.53 Ω
RT = R1 + RT = 4 Ω + 1.53 Ω = 5.53 Ω
b.
I = 40 V/5.53 Ω = 7.23 A
c.
I3 =
2 ( I )
2 (7.23 A)
= 1.69 A
2 6.56 2 6.56
2 (1.69 A)
= 0.375 mA
I7 =
2+7
PR7 I 2 R = (0.375 A)2 2 Ω = 0.281 W
Network redrawn:
24 V
=3A
8
P6Ω = I2R = (3 A)2 6 Ω = 54 W
I 8Ω = I 6Ω =
64
Chapter 7
29.
a.
b.
30.
R10 + R11 R12 = 1 Ω + 2 Ω 2 Ω = 2 Ω
R4 (R5 + R6) = 10 Ω 10 Ω = 5 Ω
R1 + R2 (R3 + 5 Ω) = 3 Ω + 6 Ω 6 Ω = 6 Ω
RT = 2 Ω 3 Ω 6 Ω = 2 Ω 2 Ω = 1 Ω
I = 12 V/1 Ω = 12 A
I1 = 12 V/6 Ω = 2 A
6 (2 A)
=1A
I3 =
6+6
1A
I4 =
= 0.5 A
2
c.
I6 = I4 = 0.5 A
12 A
=6A
2
d.
I10 =
a.
E = (40 mA)(1.6 k) = 64 V
b.
RL2 =
c.
I R1 = 72 mA 40 mA = 32 mA
48 V
= 4 k
12 mA
24 V
RL3 =
= 3 k
8 mA
I R2 = 32 mA 12 mA = 20 mA
I R3 = 20 mA 8 mA = 12 mA
R1 =
R2 =
R3 =
31.
VR1
I R1
VR2
I R2
VR3
I R3
=
64 V 48 V 16 V
=
= 0.5 k
32 mA
32 mA
=
48 V 24 V
24 V
=
= 1.2 k
20 mA
20 mA
=
24 V
= 2 k
12 mA
I R1 = 40 mA
I R2 = 40 mA 10 mA = 30 mA
I R3 = 30 mA 20 mA = 10 mA
I R5 = 40 mA
I R4 = 40 mA 4 mA = 36 mA
R1 =
R2 =
Chapter 7
VR1
I R1
VR2
I R2
=
120 V 100 V
20 V
= 0.5 k
=
40 mA
40 mA
=
100 V 40 V
60 V
=
= 2 k
30 mA
30 mA
65
R3 =
R4 =
R5 =
VR3
I R3
VR4
I R4
VR5
I R5
=
40 V
= 4 k
10 mA
=
36 V
= 1 k
36 mA
=
60 V 36 V
24 V
= 0.6 k
=
40 mA
40 mA
P1 = I12 R1 = (40 mA)20.5 k = 0.8 W (1 watt resistor)
P2 = I 22 R2 = (30 mA)22 k = 1.8 W (2 watt resistor)
P3 = I 32 R3 = (10 mA)24 k = 0.4 W (1/2 watt or 1 watt resistor)
P4 = I 42 R4 = (36 mA)21 k = 1.3 W (2 watt resistor)
P5 = I 52 R5 = (40 mA)20.6 k = 0.96 W (1 watt resistor)
All power levels less than 2 W. Four less than 1 W.
32.
80 V
= 400 Ω 390 Ω
200 mA
40 V
R2 =
= 266.67 Ω 270 Ω
150 mA
R1 =
33.
a.
yes, RL Rmax (potentiometer)
b.
VDR: VR2 = 3 V =
c.
VR1 = E VL = 12 V 3 V = 9 V (Chose VR1 rather than VR2 RL since numerator of VDR
R2 (12 V) R2 (12 V)
=
R1 R2
1k
3 V(1 k )
= 0.25 k = 250
R2 =
12 V
R1 = 1 k 0.25 k = 0.75 k = 750
equation "cleaner")
R1 (12 V)
R1 ( R2 RL )
9R1 + 9(R2 RL) = 12R1
R1 3( R2 RL )
2 eq. 2 unk( RL = 10 k)
R1 R2 1 k
3R2 10 k
3R2 RL
R1 =
R2 RL
R2 10 k
and R1(R2 + 10 k) = 30 k R2
VR1 = 9 V =
66
Chapter 7
R1R2 + 10 k R1 = 30 k R2
R1 + R2 = 1 k: (1 k R2)R2 + 10 k (1 k R2) = 30 k R2
R22 + 39 k R2 10 k2 = 0
R2 = 0.255 k, 39.255 k
R2 = 255
R1 = 1 k R2 = 745
34.
a.
b.
80 1 k = 74.07
20 10 k = 19.96
74.07 (40 V)
= 31.51 V
Vab =
74.07 + 19.96
Vbc = 40 V 31.51 V = 8.49 V
c.
P=
d.
35.
36.
37.
38.
80 (40 V)
= 32 V
100
Vbc = 40 V 32 V = 8 V
Vab =
(31.51 V ) 2 (8.49 V ) 2
+
= 12.411 W + 3.604 W = 16.02 W
80
20
(32 V ) 2 (8 V ) 2
+
= 12.8 W + 3.2 W = 16 W
80
20
The applied loads dissipate less than 20 mW of power.
P=
a.
ICS = 1 mA
b.
Rshunt =
Rm I CS
(100 )(1 mA) 0.1
=
20 A 1 mA
20
I max I CS
Ω = 5 mΩ
(1 k )(50 A)
2Ω
25 mA 0.05 mA
(1 k )(50 A)
=1Ω
50 mA: Rshunt =
50 mA 0.05 mA
100 mA: Rshunt 0.5 Ω
25 mA: Rshunt =
Vmax VVS 15 V (50 A)(1 k)
= 300 kΩ
=
I CS
50 A
a.
Rs =
b.
Ω/V = 1/ICS = 1/50 µA = 20,000
5 V (1 mA)(1000 )
= 4 kΩ
1 mA
50 V 1 V
50 V: Rs =
= 49 kΩ
1 mA
500 V 1 V
= 499 kΩ
500 V: Rs =
1 mA
5 V: Rs =
Chapter 7
67
39.
40.
10 MΩ = (0.5 V)(Ω/V) Ω/V = 20 106
1
= 0.05 μA
ICS = 1/(Ω/V) =
20 106
a.
Rs =
b.
xIm =
2 k
zero adjust
3V
E
1 kΩ
= 28 kΩ
Rm
=
2
100 A
2
Im
Runk =
E
Rseries
+ Rm +
zero adjust
+ Runk
2
zero adjust
E
Rseries Rm +
2
xI m
3V
30 103
30 103
30 kΩ
x100 A
x
3
1
1
x = , Runk = 10 kΩ; x = , Runk = 30 kΩ; x = , Runk = 90 kΩ
4
2
4
=
41.
40.
a.
Carefully redrawing the network will reveal that all three resistors are in parallel
R 12
and RT =
=4Ω
N
3
b.
Again, all three resistors are in parallel and RT =
a.
Network redrawn:
42.
R 18
=6Ω
N
3
Rohmmeter = 1.2 kΩ (3.1 kΩ + 1.2 kΩ + 1.65 kΩ)
= 1.2 kΩ 5.95 kΩ
= 1 kΩ
b.
All three resistors are in parallel
Rohmmeter =
68
R 18
=6Ω
N
3
Chapter 7
Chapter 8
1.
2.
3.
8 (6 A)
= 4.8 A
8 2
I2 = 6 A I1 = 6 A 4.8 A = 1.2 A
a.
I1 =
b.
Vs = I1R1 = (4.8 A)(2 Ω) = 9.6 V
a.
I1 = I2 = 20 mA
b.
V2 = I2R2 = (20 mA)(3.3 kΩ) = 66 V
Vs = IRT = (20 mA)((1.2 kΩ + 3.3 kΩ) = 20 mA(4.5 kΩ) = 90 V
E + VR1 Vs = 0, VR1 = (8 mA)(2.7 kΩ) = 21.6 V
Vs = E + VR1 = 10 V + 21.6 V = 31.6 V
4.
a.
b.
c.
Vs = E = 24 V
24 V
24 V
E
I2 =
=6A
4
R1 R2 1 3
I + Is = I2, Is = I2 I = 6 A 2 A = 4 A
5.
V1 = V2 = Vs = IRT = 0.6 A[6 24 24 ] = 0.6 A[6 12 ] = 2.4 V
2.4 V
V
= 0.1 A
I2 = 2
R2 24
16 (2.4 V )
R3Vs
= 1.6 V
V3 =
24
R3 R4
6.
a.
E 24 V
24 V
24
E
= 12 A, I R2 =
=3A
=
=
=
R1 2
R2 R3 6 + 2 8
KCL: I + Is I1 I R2 = 0
I1 =
I s = I1 + I R2 I = 12 A + 3 A 4 A = 11 A
b.
Vs = E = 24 V
VDR: V3 =
7.
68
R3 E
2 (24 V) 48 V
=6V
=
=
R2 R3 6 + 2 8
a.
I=
E 22 V
= 4.68 A, Rp = Rs = 4.7 Ω
=
Rs 4.7
b.
I=
9V
E
= 4.09 mA, Rp = Rs = 2.2 kΩ
=
Rs 2.2 k
CHAPTER 8
8.
9.
a.
E = IRs = (6 A)(12 Ω) = 72 V, Rs = 12 Ω
b.
E = IRs = (18 mA)(5.6 kΩ) = 100.8 V, Rs = 5.6 kΩ
a.
CDR: IL =
Es = IR = (20 A)(100 Ω) = 2 kV
Rs = 100 Ω
Es
2 kV
= 18.18 A
I=
=
Rs + RL 100 + 10
b.
10.
11.
Rs ( I )
100 (20 A)
= 18.18 A, IL I
=
Rs RL 100 + 10
a.
E = IR2 = (2 A)(5.6 Ω) = 11.2 V, R = 5.6 Ω
b.
ET = 12 V + 11.2 V = 23.2 V, RT = 10 Ω + 5.6 Ω = 15.6 Ω
c.
I3 =
a.
IT = 6.2 A 1.2 A 0.8 A = 4.2 A
b.
Vs = IT R = (4.2 A)(4 ) = 16.8 V
ET
23.2 V
= 217.64 mA
RT 91 15.6 91
12.
IT = 7 A 3 A = 4 A
R ( I ) 6 (4 A)
= 2.4 A
CDR: I1 = 2 T =
R1 R2 4 + 6
V2 = I1R1 = (2.4 A)(4 ) = 9.6 V
13.
a.
b.
Conversions: I1 = E1/R1 = 9 V/3 Ω = 3 A, R1 = 3 Ω
I2 = E2/R2 = 20 V/2 Ω = 10 A, R2 = 2 Ω
IT = 10 A 3A = 7 A, RT = 3 Ω 6 Ω 2 Ω
= 2 Ω 2 Ω
=1Ω
V ab = IT RT = (7 A)(1 Ω) = 7 V
14.
7V
= 1.17 A
6
c.
I 3 =
a.
I=
b.
IT = 8 mA + 5.45 mA 3 mA = 10.45 mA
R = 6.8 k 2.2 k = 1.66 k
V1 = ITR = (10.45 mA)(1.66 k) = 17.35 V
CHAPTER 8
E
12 V
= 5.45 mA, Rp = 2.2 kΩ
=
R2 2.2 k
69
15.
c.
V1 = V2 + 12 V V2 = V1 12 V = 17.35 V 12 V
= 5.35 V
d.
I2 =
V2 5.35 V
= 2.43 mA
=
R2 2.2 k
a.
1
7
4 4I1 8I3 = 0
6 2I2 8I3 = 0
I1 + I2 = I3
────────────
5
4
A, I 3 A
7
7
1
5
4
I1 A, I R2 I 2 A, I R3 I3 A
7
7
7
I1 = A , I 2
I R1
b.
16.
4
Va = I3R3 = A (8 ) = 4.57 V
7
10 + 12 3I3 4I1 = 0
12 3I3 12I2 = 0
I1 + I2 = I3
───────────────
a.
I1 = 3.06 A
I2 = 0.19 A
I3 = 3.25 A
I R1 I1 = 3.06 A, I R3 I 2 = 0.19 A = I12Ω
I R2 I 3 = 3.25 A
b.
I12Ω =
c.
17.
1.714 )(1.5 A)
= 0.19 A
1.714 12
the same
10 I1 5.6 kΩ I3 2.2 kΩ + 20 = 0
20 + I3 2.2 kΩ + I2 3.3 kΩ 30 = 0
I1 + I2 = I3
─────────────────────────
I1 = I R1 = 1.45 mA, I2 = I R2 = 8.51 mA, I3 = I R3 = 9.96 mA
70
CHAPTER 8
18.
1.2 kΩ I1 + 9 8.2 kΩ I3 = 0
10.2 kΩ I2 + 8.2 kΩ I3 + 6 = 0
I2 + I3 = I1
──────────────────────
a.
I1 = 2.03 mA, I2 = 1.23 mA, I3 = 0.8 mA
I R1 = I1 = 2.03 mA
I R2 = I3 = 0.8 mA
I R3 I R4 = I2 = 1.23 mA = I9.1kΩ
b.
V4 = I2R4 = (1.23 mA)(1.1 kΩ) = 1.35 V
Va = 6 V V4 = 6 V 1.35 V = 4.65 V
19.
I1 = I R1 (CW), I2 = I R2 (down), I3 = I R3 (CW), I4 = I R4 (down)
I5 = I R5 (CW)
a.
E1 I1R1 I2R2 = 0
I2R2 I3R3 I4R4 = 0
I4R4 I5R5 E2 = 0
I1 = I2 + I3
I3 = I4 + I5
────────────────
c.
I2(R1 + R2) + I3R1
+ 0
= E1
I2(R2)
I3(R3 + R4) + I5R4
=0
I5(R4 + R5) = E2
0
+ I3R4
───────────────────────────
3I2 + 2I3 + 0 = 10
1I2 9I3 + 5I5 = 0
0 + 5I3 8I5 = 6
─────────────
d.
I3 = I R 3 = 63.69 mA (CW)
CHAPTER 8
b.
E1 I2(R1 + R2) I3R1 = 0
I2R2 I3(R3 + R4) + I5R4 = 0
I3R4 I5(R4 + R5) E2 = 0
───────────────────
71
20.
a.
b.
21
a.
4 4I1 8(I1 I2) = 0
8(I2 I1) 2I2 6 = 0
───────────────
5
1
I1 = A , I2 = A
7
7
1
I R1 = I1 = A
7
5
I R2 = I2 = A
7
4
1 5
I R3 = I1 I2 = A A =
A (dir. of I1 )
7
7 7
4
Va = I R3 R3 A (8 ) = 4.57 V
7
10 4I1 3(I1 I2) 12 = 0
12 3(I2 I1) 12I2 = 0
─────────────────
I1 = 3.06 A, I2 = 0.19 A
I E1 = 3.06 A (CCW)
I E2 = 3.06 A + 0.19 A = 3.25 A (up)
I R2 = I1 I2 = (3.06 A) (0.19 A) = 3.25 A
b.
PE2 I E2 E2 = (3.25 A)(12 V) = 39 W
PR3 I R23 R3 = (0.19 A)2 12 Ω = 433.2 mW
22.
a.
10 I1(5.6 kΩ) 2.2 kΩ(I1 I2) + 20 = 0
20 2.2 kΩ(I2 I1) I2 3.3 kΩ 30 = 0
────────────────────────────
I1 = 1.45 mA, I2 = 8.51 mA
I R1 = I1 = 1.45 mA, I R2 = I2 = 8.51 mA
I R3 = I2 I1 = 7.06 mA (direction of I2)
b.
23.
a.
V3.3kΩ = I2R2 = (8.51 mA)(3.3 kΩ) = 28.1 V
I1(1.2 kΩ) + 9 8.2 kΩ(I1 I2) = 0
I2(1.1 kΩ) + 6 I2 (9.1 kΩ) 8.2 kΩ(I2 I1) = 0
──────────────────────────────────
I1 = 2.03 mA, I2 = 1.23 mA
I R1 = I1 = 2.03 mA, I R3 I R4 I 2 = 1.23 mA
I R2 I1 I 2 = 2.03 mA 1.23 mA = 0.80 mA (direction of I1)
b.
72
Va = 6 V I2(1.1 kΩ) = 6 V (1.23 mA)(1.1 kΩ) = 6 V 1.35 V = 4.65 V
CHAPTER 8
24.
10 I12 1(I1 I2) = 0
1(I2 I1) I2 4 5(I2 I3) = 0
5(I3 I2) I3 3 6 = 0
──────────────────────
3I1 1I 2 0 10
a.
1I1 10 I 2 5 I 3 0
0 5I 2 8I 3 6
I1 = 3.31 A, I2 = 63.69 mA, I3 = 789.8 mA
b, c. Ignore
d.
I10V = I1 = 3.31 A
I 6V = I3 = (789.8 mA) = 789.8 mA
25.
a.
with
or
I1 2.2 kΩ (I1 I2)9.1 kΩ + 18 V = 0
18 V (I2 I1)9.1 kΩ 7.5 kΩ I2 (I2 I3)6.8 kΩ = 0
6.8 kΩ(I3 I2) 3 V 3.3 kΩ I3 = 0
──────────────────────
11.3 kΩ I1 9.1 kΩI2 = 18 V
23.4 kΩ I2 9.1 kΩI1 6.8 kΩ I3 = 18 V
10.1 kΩ I3 6.8 kΩ I2 = 3 V
──────────────────────
11.3 kΩ I1 9.1 kΩ I2
= 18 V
9.1 kΩ I2 + 23.4 kΩ I2 6.8 kΩ I3 = 18 V
6.8 kΩ I2 + 10.1 kΩ I3 = 3 V
─────────────────────────────
b.
I1 = 1.21 mA, I2 = 0.48 mA, I3 = 0.62 mA
c.
I E1 = I1 I2 = 1.21 mA (0.48 mA) = 1.69 mA
I E2 = I3 = (0.62 mA) = 0.62 mA
26.
a.
16 4I1 3(I1 I2) 12 4(I1 I3) = 0
12 3(I2 I1) 10 I2 15 4(I2 I3) = 0
16 4(I3 I1) 4(I3 I2) 7I3 = 0
─────────────────────────────
b.
I1 = 0.24 A, I2 = 0.52 A, I3 = 1.28 A
c.
I R5 = I1 = 0.24 A
CHAPTER 8
73
27.
28.
d.
a.
6.8 k I1 4.7 k(I1 I2) + 6 2.2 k(I1 I4) = 0
6 4.7 k(I2 I1) 2.7 k I2 8.2 k (I2 I3) = 0
1.1 k I3 22 k(I3 I4) 8.2 k(I3 I2) 9 = 0
5 1.2 k I4 2.2 k(I4 I1) 22 k(I4 I3) = 0
────────────────────────────────────
b.
I1 = 0.03 mA, I2 = 0.88 mA, I3 = 0.97 mA, I4 = 0.64 mA
c.
I6V = I1 I2 = 0.03 mA (0.88 mA) = 0.91 mA,
P6V = E I6V = (6 V)(0.91 mA) = 5.46 mW
a.
Network redrawn:
b.
2I1 6 4I1 + 4I2 = 0
4I2 + 4I1 1I2 + 1I3 6 = 0
1I3 + 1I2 + 6 8I3 = 0
c.
I1 = 3.8 A, I2 = 4.20 A, I3 = 0.20 A
PE2 E2 I 3 = (6 V)(0.2 A) = 1.2 W
PE1 E1 I 2 = (6 V)(4.2 A) = 25.2 W
PT PE1 PE2 = 1.2 W + 25.2 W = 26.4 W
29.
74
a.
20 V IB(270 kΩ) 0.7 V IE(0.51 kΩ) = 0
IE(0.51 kΩ) + 8 V + IC(2.2 kΩ) 20 V = 0
IE = IB + IC
──────────────────────────────
IB = 63.02 μA, IC = 4.42 mA, IE = 4.48 mA
b.
VB = 20 V IB(270 k) = 20 V (63.02 A)(270 k) = 20 V 17.02 V = 2.98 V
VE = IERE = (4.48 mA)(510 ) = 2.28 V
VC = 20 V IC(2.2 k) = 20 V (4.42 mA)(2.2 k) = 20 V 9.72 V = 10.28 V
c.
IC/IB = 4.42 mA/63.02 A = 70.14
CHAPTER 8
30.
24 V 6I1 4I2 10I1 + 12 V = 0
and 16I1 + 4I2 = 36
I1 I2 = 6 A
───────────────────
I1 = I2 + 6 A
16[I2 + 6 A] + 4I2 = 36
16I2 + 96 + 4I2 = 36
20I2 = 60
I2 = 3 A
I1 = I2 + 6 A = 3 A + 6 A = 3 A
I24V = I6 = I10 = I12V = 3 A (CW)
I4 = 3 A (CCW)
31.
20 V 4I1 6(I1 I2) 8(I3 I2) 1I3 = 0
10I1 14I2 + 9I3 = 20
I3 I1 = 3 A
I2 = 8 A
────────────────────────
10I1 14(8 A) + 9[I1 + 3 A] = 20
19I1 = 105
I1 = 5.526 A
I3 = I1 + 3 A = 5.526 A + 3 A = 8.526 A
I2 = 8 A
I20V = I4Ω = 5.53 A (dir. of I1)
I6 = I2 I1 = 2.47 A (dir. of I2)
I8 = I3 I2 = 0.53 A (dir. of I3)
I1 = 8.53 A (dir. of I3)
CHAPTER 8
75
32.
a.
b.
33.
a.
b.
34.
(4 + 8)I1 8I2 = 4
(8 + 2)I2 8I1 = 6
─────────────
1 5 4
I8 I1 I 2 A A A
7 7 7
(4 + 3)I1 3I2 = 10 12
(3 + 12)I2 3I1 = 12
─────────────────
I 3 I 2 I1 0.19 A (3.06 A) = 3.25 A
a.
a.
I1(5.6 k + 2.2 k) 2.2 k (I2) = 10 + 20
I2(2.2 k + 3.3 k) 2.2 k (I1) = 20 30
──────────────────────────────
b.
I E1 = I1 = 1.45 mA, I E2 = 8.51 mA,
I E3 = I1 I2 = (1.45 mA) (8.5 mA) = 9.96 mA
35.
36.
a.
b.
I1(2 + 1) 1I2 = 10
I2(1 + 4 + 5) 1I1 5I3 = 0
I3(5 + 3) 5I2 = 6
───────────────────
I1 = 3.31 A, I2 = 63.69 mA, I3 = 789.8 mA
c.
I R2 I1 I 2 = (3.31 A) (63.69 mA) = 3.37 A
a.
b.
(2.2 k + 9.1 k)I1 9.1 kI2 = 18
(9.1 k + 7.5 k + 6.8 k)I2 9.1 k I1 6.8 kI3 = 18
(6.8 k + 3.3 k)I3 6.8 kI2 = 3
───────────────────────────
I1 = 1.21 mA, I2 = 0.48 mA, I3 = 0.62 mA
c.
I E1 = I1 I2 = 1.21 mA (0.48 mA) = 1.69 mA
I E2 = I3 = (0.62 mA) = 0.62 mA
76
CHAPTER 8
37.
(3 Ω + 6 Ω)I1 6 Ω I2 = 9 V
(6 Ω + 2 Ω)I2 6 Ω I1 = 20 V
────────────────────
a.
9 Ω I1 6 Ω I2 = 9 V
6 Ω I1 + 8 Ω I2 = 20 V
────────────────────
I1 = 5.33 A, I2 = 6.5 A
b.
38.
39.
Vab = 2 Ω (I2) 20 V = 2 Ω = 2 Ω(6.5 A) 20 V = 13 V 20 V = 7 V
a.
I1(6.8 k + 4.7 k + 2.2 k) 4.7 k I2 2.2 k I4 = 6
I2(2.7 k + 8.2 k + 4.7 k) 4.7 k I1 8.2 k I3 = 6
I3(8.2 k + 1.1 k + 22 k) 22 k I4 8.2 k I2 = 9
I4(2.2 k + 22 k + 1.2 k) 2.2 k I1 22 k I3 = 5
───────────────────────────
b.
I1 = 0.03 mA, I2 = 0.88 mA, I3 = 0.97 mA, I4 = 0.64 mA
c.
I 22k = I4 I3 = (0.64 mA) (0.97 mA) = 0.33 mA
V22kΩ = I22kΩ 22 kΩ = (0.33 mA)(22 kΩ) = 7.26 V
a.
(1 Ω + 2 Ω + 4 Ω)I1 2 ΩI2 4 ΩI3 = 12 V
(2 Ω + 2 Ω + 10 Ω)I2 2 ΩI1 10 ΩI3 = 20 V
(4 Ω + 10 Ω + 8 Ω)I3 10 ΩI2 4 ΩI1 = 20 V
───────────────────────────
7I1 2I2 4I3 = 12
2I1 14I2 + 10I3 = 20
4I1 + 10I2 22I3 = 20
────────────────
b.
I1 = 2.38 A, I2 = 0.195 A, I3 = 1.25 A
c.
Va = (I1 I3)4 Ω = (2.38 A 1.25 A)4 Ω = 4.5 V
Vb = I38 Ω = (1.25 A)(8 Ω) = 10 V
d.
Vab = Va Vb = 4.5 V 10 V = 5.5 V
CHAPTER 8
77
40.
a.
At V1: I i I o
0
V1
V V
5A 1 2
2
8
Ii Io
At V2:
V1 V2
V
3A 2
8
4
and
41.
1 1
1
V1 V2 5
2 8
8
1
1 1
V1 V2 3
8
8 4
───────────────────────────
b.
V1 = 10.27 V, V2 = 11.36 V
c.
V8Ω = V1 V2 = 10.27 V (11.36 V) = 1.09 V
d.
I 2 =
a.
V1 10.27 V
= 5.14 A
2
2
V
11.36 V
I 4 = 2
= 2.84 A
4
4
At V1: I i I o
V1
12 A I 6 and V1 I 6 54 V V2 0
8
V V 54 V V1
V
or I = 1 2
2 9 A
6
6 6
V1
V1
V2
12 A
9A
so that 0 =
8
6 6
1
1
1
or V1
V2
= 12 A + 9 A = 3 A
8 6
6
0
At V2: I i I o
V2
V
2
20 5
V1
V2
V
V
9 A 2 2
6 6
20 5
I
or
1
1
1
1
and V2
V1
= 9 A
6
6 20 5
78
CHAPTER 8
42.
b.
1
1
1
resulting in V1
V2
= 3 A
6
8 6
1
1
1
1
= 9 A
V1
V2
6
6 20 5
──────────────────────────────
V1 = 29.29 V, V2 = 33.34 V
c.
I 20
a.
V2
33.34 V
= 1.67 A
20
20
At V1: I i I o
V1 V1 V2
2A
2
4
4A
Ar V2: I i I o
2A
or
43.
V1 V2
V
V
2 2
4
20 5
1 1
1
V1 V2 2
2 4
4
1
1 1 1
V1 V2
2
4
4 20 5
b.
V1 = 4.8 V, V2 = 6.4 V
c.
I1: P = V1I1 = (4.8 V)(4 A) = 19.2 W
I2: P = (V1 V2 ) I 2 (4.8 V 6.4 V)(2 A) = 3.2 W
a.
At V1: I i I o
0 6A
V1 V1 V2 V1 V2
5
3
2
At V2: I i I o
7A
V1 V2 V1 V2 V2
V
2
3
2
4 8
1
1
1
1
1
so that V1
= 6 A
V2
3 2
5 3 2
1
1
1
1
1
1
=7A
V2
V1
3 2
4 8 3 2
────────────────────────────────────
or 1.03V1 0.833V2 = 6
0.833V1 + 1.21V2 = 7
───────────────────
CHAPTER 8
79
44.
b.
V1 = 2.59 V, V2 = 4 V
c.
V2Ω = V3Ω = V2 V1 = 4 V (2.59 V) = 6.59 V
V5Ω = V1 = 2.59 V
V4Ω = V8Ω = V2 = 4 V
a.
Source conversion: I3 =
12 V
= 3 A, Rp = R3 = 4 Ω
4
At V1: I i I o
0
V1
V
V V
1 5 A 1 2 + 3 A
3 6
4
At V2: I i I o
3A
V1 V2 V2
4A
4
8
Rewritten:
b.
c.
45.
1
1 V2
1
V1
= 5 A 3 A
3 6 4 4
1
1
1
V1
V2
= 4 A + 3A
4 8
4
V1 = 14.86 V, V2 = 12.57 V
14.86 V
I 6
= 2.48 A
6
a.
Source Conversion: I2 =
At V1: I i I o
5A
15 V
= 5 A, Rp = R1 = 3 Ω
3
V1 V1 V2 V1 V3
3
6
6
At V2: I i I o
V V3
V1 V2 V2
3 A 2
6
4
5
At V3: I i I o
V1 V3 V2 V3 V3
6
5
7
80
CHAPTER 8
Rewritten:
1
1
1
1
1
V1
V2
V3 = 5 A
3
6
6
6
6
1
1
1
1
1
V2
V1
V3 = 3 A
6
4
5
6
5
1
1
1
1
1
V3
V2
V1 = 0
6
5
7
5
6
────────────────────────────────────
46.
b.
V1 = 7.24 V, V2 = 2.45 V, V3 = 1.41 V
c.
V5 = V3 V2 = 1.41 V (2.45 V) = 3.86 V
+
a.
Source Conversion: I2 =
16 V
= 4 A, Rp = R2 = 4 Ω
4
At V1: I i I o
02 A+
V1 V1 V3 V1 V2
9 20
20
At V2: I i I o
V1 V2 V2 V3
V
2
20
20 18
At V3: I i I o
V1 V3 V2 V3
V
4A 3
20
20
4
Rewritten:
1
1
1
1
1
V1
V2
V3 = 2 A
20
9 20 20 20
1
1
1
1
1
V2
V1
V3 = 0
20
20 20 18 20
1
1
1
1
1
V3
V2
V1 = 4A
20
20 20 4 20
────────────────────────────────────
CHAPTER 8
b.
V1 = 6.64 V, V2 = 1.29 V, V3 = 10.66 V
c.
VR6 = V3 V1 = 10.66 V (6.64 V) = 17.30 V
+
81
47.
a.
At V1: I i I o
05 A
V1 V1 V2
2
2
At V2: I i I o
V V3
V1 V2 V2
V
2 2
2
9 7
2
At V3: I i I o
V2 V3
V
V
5 A 3 3
2
2 4
Rewritten:
1
1
1
2 2 V1 2 V2 0 = 5 A
1
1
1
1
1
1
2 9 7 2 V2 2 V1 2 V3 = 0
1
1
1
1
V3
V3
V2 = 5A
2
2 2 4
────────────────────────────────────
48.
b.
V1 = 5.31 V, V2 = 0.62 V, V3 = 3.75 V
c.
I9
V2
0.62 V
= 68.9 mA
9
9
a.
At V1: I i I o
05 A+
V1 V1 V3
2
6
At V2: I i I o
5A2 A
V2
4
At V3: I i I o
V1 V3
V
2A 3
6
5
82
CHAPTER 8
Rewritten:
1
1
1
V1
V3 = 5 A
2
6
6
1
V2
=5A2A
4
1
1
1
V3
V1 = 2A
6
5
6
───────────────────────
49.
b.
V1 = 6.92 V, V2 = 12 V, V3 = 2.3 V
c.
I 4Ω =
V2 12 V
=3A
4 4
a.
Ii Io
Node V1:
2A=
V1 V1 V2
6 10
Supernode V2, V3:
V
V V
V
0= 2 1 2 3
10
4 12
Independent source:
V2 V3 = 24 V or V3 = V2 24 V
2 eq. 2 unknowns:
V1 V1 V2
=2A
6 10
V2 V1 V2 V2 24 V
=0
10
4
12
─────────────────────
0.267V1 0.1V2 = 2
+0.1V1 0.433V2 = 2
────────────────
V1 = 10.08 V, V2 = 6.94 V
V3 = V2 24 V = 17.06 V
CHAPTER 8
83
50.
Ii Io
Supernode:
3A+4A=3A+
V1
V
2
20 40
V1
V
2
4 A
2 eq. 2 unk.
20 40
V2 V1 16 V
Subt. V2 = 16 V + V1
V
(16 V V1 )
4A= 1
20
40
and V1 = 48 V
V2 = 16 V + V1 = 64 V
──────────────────
51.
a.
1 1
1
V1 V2 = 5
2 8
8
1
1 1
V1 V2 = 3
8
8 4
────────────────────
V1 = 10.27 V, V2 = 11.36 V
b.
52.
VI1 = V1 = 10.27 V, VI 2 = V2 = 11.36 V
a.
1 1
1
V1 V2 = 12 A + 9 A = 3 A
8
6
6
1 1 1
1
V2 V1 = 9 A
20
5
6
6
──────────────────────────────
V1 = 29.29 V, V2 = 33.34 V
84
CHAPTER 8
b.
53.
V1 V6Ω 54 V V2 = 0
V6 = V1 V2 54 V = 29.29 V (33.34 V) 54 V = 49.95 V
+
a.
1
1
1
1
1
V1
V2
V3 = 2 A
20
9 20 20 20
1
1
1
1
1
V2
V1
V3 = 0
20
20 20 18 20
1
1
1
1
1
V3
V2
V1 = 4A
20
20 20 4 20
V1 = 6.64 V, V2 = 1.29 V, V3 = 10.66 V
b.
54.
Original Network:
V4Ω = 16 V V3 = 16 V 10.66 V = 5.34 V
5.34 V
I 4Ω =
= 1.34 A
4
a.
1
1
1
2 2 V1 2 V2 0 = 5 A
1
1
1
1
1
1
2 9 7 2 V2 2 V1 2 V3 = 0
1
1
1
1
2 2 4 V3 2 V2 = 5A
────────────────────────────────────
CHAPTER 8
b.
V1 = 5.31 V, V2 = 0.62 V, V3 = 3.75 V
c.
I9
V2
0.62 V
= 68.89 mA
9
9
85
55.
56.
1
1
1
V1
V3 = 5 A
2 6 6
1
V2
=5A2A
4
1
1
1
V3
V1 = 2A
6 5 6
───────────────────────
a.
b.
V1 = 6.92 V, V2 = 12 V, V3 = 2.3 V
c.
I 2Ω =
V2
6.92 V
= 3.46 A
2
2
a.
1
1
1
1
1
V1
V2
V3 = 12 A
2
1 2 2 2
1
1
1
1
1
V2
V1
V3 = 2 A
10
2 4 10 2
1
1
1
1
1
V3
V1
V2 = 2A
10
2 10 8 2
────────────────────────────────────
and
2V1 0.5V2 0.5V3 = 12
0.5V1 + 0.85V2 0.1V3 = 2
0.5V1 0.1V2 + 0.725V3 = 2
───────────────────────
V1 = 9.63 V, V2 = 4.49 V, V3 = 10.02 V
b.
57.
Vab = V2 V3 = 4.49 V 10.02 V = 5.53 V
a.
I1(6 Ω + 2 Ω + 10 Ω) 2 ΩI2 10 ΩI3 = 12 V
I2(2 Ω + 5 Ω + 5 Ω) 2 ΩI1 5 ΩI3 = 0
I3(5 Ω + 20 Ω + 10 Ω) 10 ΩI1 5 ΩI2 = 0
or
18I1 2I2 10I3 = 12
2I1 + 12I2 5I3 = 0
10I1 5I2 + 35I3 = 0
───────────────
I1 = 850.99 mA, I2 = 258.53 mA, I3 = 280.07 mA
86
CHAPTER 8
58.
b.
I R5 = I3 I2 = 280.07 mA 258.53 mA = 21.54 mA
c.
no
d.
no 2 Ω/10 Ω =
1
1
5 Ω/20 Ω =
5
4
a.
1
1
1
1
1
V1
V2
V3 = 2 A
5
6 2 5 2
1
1
1
1
1
V2
V1
V3 = 0
5
2 5 10 2
1
1
1
1
1
V3
V2
V1 = 0
5
5 5 20 5
────────────────────────────────────
or 0.867V1 0.5V2 0.2V3 = 12
0.5V1 + 0.8V2 0.2V3 = 0
0.2V1 0.2V2 + 0.45V3 = 0
───────────────────────
V2 = 5.7 V, V3 = 5.6 V
59.
b.
V5Ω = V2 V3 = 5.7 V 5.6 V = 0.1 V
c.
no
d.
no 2 Ω/10 Ω =
1
1
5 Ω/20 Ω =
5
4
a.
Source conversion: E = IR = (12 m)(2 kΩ) = 24 V
Rs = 2 kΩ
I1(2 kΩ + 33 kΩ + 3.3 kΩ) 33 kΩI2 3.3 kΩI3 = 24 V
I2(33 kΩ + 56 kΩ + 36 kΩ) 33 kΩI1 36 kΩI3 = 0
I3(36 kΩ + 3.3 kΩ + 5.6 kΩ) 3.3 kΩI1 36 kΩI2 = 0
────────────────────────────────────
I1 = 0.97 mA, I2 = I3 = 0.36 mA
b.
I5 = I2 I3 = 0.36 mA 0.36 mA = 0 mA
c, d. yes
CHAPTER 8
87
60.
a.
1
1
1
1
1
V1
V2
V3 = 12 mA
56 k
2 k 33 k 56 k 33 k
1
1
1
1
1
V2
V1
V3 = 0
36 k
33 k 3.3 k 36 k 33 k
1
1
1
1
1
V3
V2
V1 = 0
56 k
56 k 36 k 5.6 k 36 k
────────────────────────────────────
Rewritten:
548.16V1 30.3V2 17.86V3 = 12 × 103
30.3V1 + 361.11V1 27.78V3 = 0
17.86V1 27.78V2 + 224.21V3 = 0
────────────────────────────
V2 = 2.01 V, V3 = 2.01 V
b.
VR5 = V2 V3 = 2.01 V 2.01 V = 0 V
c, d. yes
61.
Mesh Analysis
(1 k + 2 k + 2 k)I1 2 k I2 2 k I3 = 10
(2 k + 2 k + 2 k)I2 2 k I1 2 k I3 = 0
(2 k + 2 k + 2 k)I3 2 k I1 2 k I2 = 0
─────────────────────────────────
I1 = I10V = 3.33 mA
Nodal Analysis:
Source conversion: I = 10 V/1 kΩ = 10 mA, R = 1 kΩ
1
1
1
1
1
V1
V2
V3 = 10 mA
+
+
2 k
1 k 2 k 2 k 2 k
1
1
1
1
1
V2
V1
V3 = 0
+
+
2 k
2 k 2 k 2 k 2 k
1
1
1
1
1
V3
V2
V1 = 0
+
+
2
k
2
k
2
k
2
k
2
k
──────────────────────────────────────
V1 = 6.67 V = E IRs = 10 V I(1 k)
10 6.67 V
= 3.33 mA
I=
1k
88
CHAPTER 8
62.
Mesh Analysis
Source conversion: E = 20 V, R = 10
(10 + 10 + 20)I1 10I2 20I3 = 20
(10 + 20 + 20)I2 10I1 20I3 = 0
(20 + 20 + 10)I3 20I1 20I2 = 0
──────────────────────
I1 = I20V = 0.83 A
V 20 V 8.3 V
= 11.7 V
Is =
V 11.70 V
= 1.17A
10
Rs
Nodal Analysis:
1
1 1
1
1
V1 V2 V3 2
10 10 20 20
10
1
1 1
1
1
V2
V1 V3 0
20 20 10 20
20
1
1 1
1
1
V3
V1 V2 0
10 20 20 10
20
───────────────────────
V
I Rs = 1 = 1.17 A
Rs
63.
I=
=
20 V
4
2
2
+ + 3 + 4
5
5
5
20 V
4
+ (3.14 ) (4.4 )
5
= 7.36 A
CHAPTER 8
89
64.
RT = 2.27 k + [4.7 k + 2.27 k] [1.1 k + 2.27 k]
= 2.27 k + [6.97 k] [3.37 k]
= 2.27 k + 2.27 k
= 4.54 k
8V
= 1.76 mA
I=
4.54 k
(Y-Δ conversion)
400 V
400 V
I=
12 k 12 k 6 k
3 k
= 133.33 mA
65.
66.
a.
I=
42 V
42 V
(18 18 ) (18 18 ) (18 18 ) 9 9 9
= 7 A (YΔ conversion)
b.
Y conversion
I s1 =
10 V
5V
15 V
= 0.83 mA
+
=
18 k 18 k 18 k
67.
90
CHAPTER 8
68.
a.
b.
69.
R = R1 + 1 k = 3 k
R = R2 + 1 k = 3 k
3k
= 1.5 k
RT =
2
RT = 1 k + 1.5 k + 1 k = 3.5 k
E
20 V
= 5.71 mA
Is =
=
RT 3.5 k
Using two Y conversions:
c g: 27 9 27 = 5.4
a h: 27 9 27 = 5.4
RT = 5.4 (13.5 + 5.4 )
= 5.4 18.9
= 4.2
CHAPTER 8
91
Chapter 9
1.
a.
RT (from source) = 4 Ω + 2 Ω 12 Ω
= 4 Ω + 1.71 Ω
= 5.71 Ω
E1
16 V
Is
2.8 A
RT 5.71 V
2 (2.8 A)
0.4 A
I12
2 12
E1:
RT (from source) = 2 Ω + 4 Ω 12 Ω
=2Ω+3Ω
=5Ω
E2 10 V
Is
2A
RT
5
4 (2 A)
0.5 A
I12
4 12
E2:
I12Ω = 0.5 A 0.4 A = 0.1 A
b.
I12
c.
2.
1.333 (1A)
= 0.1 A
1.333 12
the same
a.
24 (3 A)
= 2.25 A
24 8
V I R = (2.25)(4.7 Ω) = 10.575 V
I
V
4.7 (12 V)
= 1.763 V
4.7 3.3 24
V 10.575 V 1.763 V = 8.81 V
92
CHAPTER 9
b.
c.
3.
V 2 (10.575 V)2
= 23.79 W
R
4.7
V 2 (1.763 V) 2
P=
= 0.661 W
R
4.7
P=
V 2 (8.81 V) 2
= 16.51 W
R
4.7
d.
P=
e.
23.79 W + 0.661 W 16.51 W
24.45 W 16.51 W
E:
RT = 12 24 56 28.8
24 V
E
Is =
= 0.833 A
RT 28.8
24 (0.833 A)
I 56
= 0.25 A
24 56
I:
24 56 16.8
12 (8 A)
I
= 3.33 A
12 16.8
24 (3.33 A)
I 56
=1A
24 56
I 56 I I 0.25 A+1 A = 1.25 A
4.
E1:
42 V
= 1.944 A
18 + 3.6
9 ( IT ) 9 (1.944 A)
I1 =
96
15
= 1.17 A
IT =
E2:
IT =
E2 24 V
=2A
RT 12
I24V = IT + I1 = 2 A + 1.17 A = 3.17 A (dir. of I1)
CHAPTER 9
93
5.
E:
V2 =
6.8 k(36 V)
= 13.02 V
6.8 k 12 k
I:
I2 =
12 k(9 mA)
= 5.75 mA
12 k 6.8 k
V2 I 2 R2 = (5.75 mA)(6.8 k) = 39.10 V
V2 = V2 V2 = 13.02 V + 39.10 V = 52.12 V
6.
1.2 k 4.7 k 0.956 k
3.3 kΩ + 0.956 kΩ = 4.256 kΩ
4.256 k(5 mA)
I
2.2 k 4.256 k
3.3mA
I:
E:
I I I = 3.3 mA + 0.986 mA = 4.286 mA
7.
E1:
I1 =
94
2.2 kΩ + 3.3 kΩ = 5.5 k Ω
5.5 k 4.7 k 2.53 k
RT = 2.54 kΩ + 1.2 kΩ = 3.73 kΩ
8V
Is
= 2.14 mA
3.73 k
4.7 k(21.4 mA)
I
= 0.986 mA
4.7 k 5.5 k
E1
12 V
= 1.03 A
RT 6 5.88
CHAPTER 9
30 ( I1 )
30 (1.03 A)
30 7
37
835.14 mA
Vs = I(4 ) = (835.14 mA)(4 )
= 3.34 V
I
I:
8 (6 A)
=4A
8 4
Vs = I(4 ) = 4 A(4 ) = 16 V
I =
E2:
RT = 12 (4 + 5 ) = 12 9 = 5.14
E
8V
I = 2
0.875 A
RT 4 5.14
12 ( I )
12 (0.875 A)
I =
0.5 A
12 9
21
Vs I (4 ) = 0.5 A(4 ) = 2 V
Vs = Vs Vs Vs = 16 V 3.34 V 2 V = 10.66 V
8.
a.
RTh = R3 + R1 R2 = 4 Ω + 6 Ω 3 Ω = 4 Ω + 2 Ω = 6 Ω
R2 E
3 (18 V)
ETh =
6V
R2 R1 3 6
CHAPTER 9
95
9.
b.
I1 =
a.
RTh:
ETh
6V
= 0.75 A
=
RTh R 6 + 2
6V
= 166.67 mA
I2 =
6 + 30
6V
I3 =
= 56.60 mA
6 + 100
RTh 3.3 k 1.2 k 2.4 k
3.3 k 0.8 k
4.1 k
ETh:
ETh (120 mA)(2.4 k 1.2 k)
96 V
RTh = 4.1 kΩ
b.
96 V
= 15.74 mA
6.1 k
P = I2R = (15.74 mA)2 2 kΩ = 0.495 W
R = 100 kΩ:
96 V
= 0.922 mA
I=
104.1 k
P = I2R = (0.922 mA)2 100 kΩ = 85 mW
I=
10.
a.
RTh:
RTh = 5 Ω + 5 Ω 5 Ω = 7.5 Ω
ETh:
ETh =
96
20 V
= 10 V
2
CHAPTER 9
2
b.
ETh
10 V
R = 2 Ω: P =
R =
2 = 2.22 W
R
R
7.5
2
Th
2
2
10 V
R = 100 Ω: P =
100 = 0.87 W
7.5
100
11.
RTh = 3 Ω 8 Ω = 2.18 Ω
18 V + 12 V
= 2.73 A
3 8
V3Ω = IR = (2.73 A)(3 Ω) = 8.19 V
ETh = 18 V 8.19 V = 9.81 V
I=
12.
RTh:
RTh = 5.6 kΩ 2.2 kΩ = 1.58 kΩ
ETh: Superposition:
I:
ETh = IRT
= 8 mA(5.6 k 2.2 k)
= 8 mA(1.579 k)
= 12.64 V
E:
5.6 k(16 V)
5.6 k 2.2 k
= 11.49 V
ETh =
+
ETh = 11.49 V 12.64 V = 1.15 V
CHAPTER 9
97
13.
RTh:
RTh = 4 (2 + 6 Ω 3 ) = 2
ETh:
72 V
=9A
6 3 (2 4 )
3 ( IT ) 3 (9 A)
=3A
I2 =
3 6
9
ETh = V6 + V2 = (IT)(6 ) + I2(2 )
= (9 A)(6 ) + (3 A)(2 ) = 60 V
IT =
14.
a.
RTh:
RTh = 2.7 k (4.7 k + 3.9 k) = 2.7 k 8.6 k = 2.06 k
ETh:
I =
3.9 k(18 mA)
= 6.21 mA
3.9 k 7.4 k
ETh = I(2.7 k) = (6.21 mA)(2.7 k) = 16.77 V
b.
16.77 V
16.77 V
2.06 k 1.2 k 3.26 k
= 5.14 mA
I=
98
CHAPTER 9
15.
a.
RTh:
RTh = 2 + 8 = 10
ETh:
ETh = V16
20 V
= 825.08 mA
20 4.24
5 ( IT )
5 (825.08 mA)
= 125.01 mA
I =
5 28
33
ETh = V16Ω = (I)(16 Ω) = (125.01 mA)(16 Ω) = 2 V
IT =
b.
16.
a.
20 Ω:
ETh
2V
2V
= 66.67 mA
RTh R 10 20 30
2V
2V
= 33.33 mA
50 Ω: I =
10 50 60
2V
2V
100 Ω: I =
= 18.18 mA
10 100 110
I =
RTh:
RTh = 3. 3 k + 2.2 k 1.1 k
= 3.3 k + 0.73 k
= 4.03 k
ETh: Superposition:
E1:
ETh = V2.2kΩ =
2.2 k(12 V)
2.2 k 1.1 k
=8V
CHAPTER 9
99
ETh = E2 = 4 V
ETh = ETh + ETh = 8 V + 4 V = 12 V
b.
V=
17.
1.2 k(12 V)
= 2.75 V
1.2 k 4.03 k
RTh:
RTh = 2.2 k 5.6 k = 1.58 k
R = 1.58 k + 3.3 k
= 4.88 k
R = 4.88 k 6.8 k = 2.84 k
RTh = 1.2 k + R = 1.2 k + 2.84 k = 4.04 k
ETh: Source conversions:
22 V
= 10 mA, Rs = 2.2 k
I1 =
2.2 k
12 V
I2 =
= 2.14 mA, Rs = 5.6 k
5.6 k
Combining parallel current sources: IT = I1 I2 = 10 mA 2.14 mA = 7.86 mA
2.2 k 5.6 k = 1.58 k
100
CHAPTER 9
Source conversion:
E = (7.86 mA)(1.58 k) = 12.42 V
R = Rs + 3.3 k = 1.58 k + 3.3 k = 4.88 k
I=
12.42 V 6 V
6.42 V
= 549.66 A
4.88 k 6.8 k 11.68 k
V6.8kΩ = I(6.8 k) = (549.66 A)(6.8 k) = 3.74 V
ETh = 6 V + V6.8kΩ = 6 V + 3.74 V = 9.74 V
18.
a.
RTh:
RTh = 51 k 10 k = 8.36 k
ETh:
ETh =
b.
10 k(20 V)
= 3.28 V
10 k 51 k
IERE + VCE + ICRC = 20 V
but IC = IE
and IE(RC + RE) + VCE = 20 V
20 V VCE
20 V 8 V
12 V
= 4.44 mA
or IE =
2.2 k 0.5 k 2.7 k
RC RE
c.
ETh IBRTh VBE VE = 0
E VBE VE 3.28 V 0.7 V (4.44 mA)(0.5 k)
and IB = Th
8.36 k
RTh
2.58 V 2.22 V 0.36 V
= 43.06 μA
=
=
8.36 k
8.36 k
CHAPTER 9
101
19.
d.
VC = 20 V ICRC = 20 V (4.44 mA)(2.2 k)
= 20 V 9.77 V
= 10.23 V
a.
ETh = 20 V
I = 1.6 mA =
ETh 20 V
20 V
= 12.5 k
, RTh
1.6 mA
RTh
RTh
b.
ETh= 60 mV, RTh = 2.72 k
c.
ETh = 16 V, RTh = 2.2 k
20.
RTh = 4 (2 2 )
4
=2
2
2 (6 V)
12 V
= 1.5 V
2 4 2 8
V2Ω = V4Ω = 1.5 V
ETh = V4Ω + V2Ω = 1.5 V + 1.5 V = 3 V
V4Ω =
21.
a.
From Problem 8, RN = RTh = 6 Ω
RT 6 3 4
6 1.714 7.714
E
18 V
Is =
= 2.333 A
RT 7.714
3 (2.333 A)
=1A
IN =
3 4
102
b.
RTh = 6 Ω, ETh = INRN = (1 A)(6 Ω) = 6 V
c.
same results
CHAPTER 9
22.
a.
From Problem 9, RN = RTh = 4.1 kΩ
2.4 k(120 mA)
2.4 k (1.2 k 3.3 k)
87.80 mA
I
1.2 k(87.80 mA)
1.2 k 3.3 k
23.41 mA
RTh = 4.1 kΩ, ETh = INRN = (23.41 mA)(4.1 kΩ) = 96 V
same results.
IN
b.
c.
23.
From Problem 11, RN = RTh = 2.18 Ω
IN = 6 A 1.5 A = 4.5 A
24.
From Problem 12, RN = RTh = 1.58 kΩ
IN = 8 mA 7.27 mA = 0.73 mA
25.
From Problem 13, RN = RTh = 2 Ω
72 V
= 18 A
4
72 V
I 3Ω =
= 16 A
3 6 2
6 (16 A)
I 2Ω =
= 12 A
6 2
IN = I4Ω + I2Ω = 18 A + 12 A = 30 A
I 4Ω =
CHAPTER 9
103
26.
From Problem 15, RN = RTh = 10 Ω
RT = 20 Ω + 5 Ω (12 Ω + 1.778 Ω) = 23.67 Ω
E
20 V
Is =
= 844.95 mA
RT 23.67
5 (844.95 mA)
=224. 98 mA
I12Ω =
5 (12 1.778 )
16 (224.98 mA)
IN =
= 200 mA
16 2
27.
104
From Problem 17, RN = RTh = 4.04 kΩ
CHAPTER 9
4.88 k(3.427 mA)
4.88 k 1.02 k
2.83 mA
I
IN =
28.
6.8 k(2.83 mA)
= 2.41 mA
6.8 k k
From Problem 20, RN = RTh = 2 Ω
IN
29.
a.
6V
= 1.5 A
4
RN:
RN = 4 12 = 3
E = 12 V:
IN =
CHAPTER 9
12 V
=3A
4
105
I = 2 A:
IN = 2 A
IN = IN + IN = 3 A + 2 A = 5 A
b.
I:
3 (5A)
3
145.63 mA
I
V IR
(145.63 mA)(100 )
14.56 V
E:
100 (72 V)
100 3
69.9 V
V100 V V
V
69.9 V 14.56 V
55.34 V
30.
31.
106
a.
R = RTh = 6 Ω from Problem 8
b.
ETh = 6 V from Problem 8
E2
(6 V)2
= 1.5 W
Pmax = Th
4 RTh 4(6 )
a.
R = RTh = 2.18 Ω from Problem 11
b.
ETh = 9.81 V from Problem 11
2
ETh
(9.81 V) 2
= 11.06 W
Pmax =
4 RTh 4(2.18 )
CHAPTER 9
32.
33.
34.
a.
R = RTh = 2 Ω from Problem 13
b.
ETh = 60 V from Problem 13
E2
(60 V) 2
= 450 W
Pmax = Th
4 RTh 4(2 )
a.
R = RTh = 4.04 kΩ from Problem 17
b.
ETh = 9.74 V from Problem 17
E2
(9.74 V)2
= 5.87 mW
Pmax = Th
4 RTh 4.04 k)
a.
R = RN = RTh = 2.18 Ω
b.
Pmax =
I N2 RN (13.33A)2 2.18
= 96.84 W
4
4
2
35.
36.
ETh
Pmax =
R4
RTh R4
with R1 = 0 Ω, ETh is a maximum and RTh is a minimum.
R1 = 0 Ω
a.
V, and therefore V4 wll be its largest value
when R2 is as large as possible. Therefore,
choose R2 = open-circuit ( Ω) and
V2
P4 = 4 will be a maximum.
R4
b.
37.
No, examine each individually.
The voltage VL will be a maximum when R = 500 Ω because the full voltage, E, will appear
across RL.
Pmax =
CHAPTER 9
VL2 E 2 (12 V) 2
= 1.44 W
RL RL
500
107
IT = 4 A + 7 A = 11 A
RT = 10 6 3 = 1.67
VL = ITRT = (11 A)(1.67 ) = 18.37 V
V
18.37 V
IL = L
= 6.12 A
RL
3
38.
39.
5 V / 2.2 k 20 V / 8.2 k
= 0.2879 V
1/ 2.2 k 1/ 8.2 k
1
Req =
= 1.7346 k
1/ 2.2 k 1/ 8.2 k
Eeq
0.2879 V
IL =
= 39.3 μA
Req RL 1.7346 k 5.6 k
Eeq =
VL = ILRL = (39.3 µA)(5.6 k) = 220 mV
40.
41.
42.
IT = 5 A 0.4 A 0.2 A = 4.40 A
RT = 200 80 50 Ω 50 = 17.39
VL = ITRT = (4.40 A)(17.39 ) = 75.52 V
V
76.52 V
= 0.38 A
IL = L
RL
200
(4 A)(4.7 ) (1.6 A)(3.3 ) 18.8 V + 5.28 V
= 3.01 A
4.7 3.3
8
Req = 4.7 + 3.3 = 8
Req ( I eq ) 8 (3.01 A)
=
= 2.25 A
IL =
Req + RL 8 + 2.7
VL = ILRL = (2.25 A)(2.7 Ω) = 6.08 V
Ieq =
(4 mA)(8.2 k) (8 mA)(4.7 k) (10 mA)(2 k)
I eq =
8.2 k 4.7 k 2 k
32.8 V + 37.6 V 20 V
= 3.38 mA
=
14.9 k
Req = 8.2 k + 4.7 k + 2 k = 14.9 k
Req I eq
(14.9 k)(3.38 mA)
IL =
= 2.32 mA
=
Req + RL
14.9 k 6.8 k
VL = ILRL = (2.32 mA)(6.8 k) = 15.78 V
108
CHAPTER 9
43.
15 k (8 k + 7 k) = 15 k 15 k = 7.5 k
7.5 k(60 V)
= 45 V
Vab =
7.5 k 2.5 k
45 V
Iab =
= 3 mA
15 k
44.
10 V 8 V
2 k 0.51 k 1.5 k
= 498.75 A
V0.51kΩ = (498.75 A)(0.51 k)
= 0.25 V
Vab = 10 V 0.25 V = 9.75 V
Iba =
45.
Vab = 0 V (short)
Iab = 0 A (open)
R2 any resistive value
R2 = short-circuit, open-circuit, any value
46.
a.
Is =
b.
c.
CHAPTER 9
I
24 V
= 1.5 mA, I = s = 0.5 mA
24 k
3
8 k
3
24 V
= 0.83 mA
24 k 8 k 12 k
12 k( I s )
I=
= 0.5 mA
12 k 8 k
Is =
yes
109
47.
(a)
10 V
4 k 8 k 4 k 4 k
10 V
=
2.67 k 2 k
10 V
=
= 2.14 mA
4.67 k
IT =
8 ( I T )
= 1.43 mA, I2 = IT/2 = 1.07 mA
8 4
I = I1 I2 = 1.43 mA 1.07 mA = 0.36 mA
I1 =
(8 k 4 k)(10 V)
8 k 4 k 4 k 4 k
= 5.72 V
V
I1 = 1 = 0.71 mA
8 k
V2 = E V1 = 10 V 5.72 V
= 4.28 V
V2
= 1.07 mA
I2 =
4 k
I = I2 I1 = 1.07 mA 0.71 mA
= 0.36 mA
(b)
48.
a.
b.
110
V1 =
R1 ( I )
3 (6 A)
=2A
R1 R2 R3 3 2 4
V = I R2 R2 = (2 A)(2 ) = 4 V
I R2
R2 ( I )
2 (6 A)
= 1.33 A
R1 R2 R3 3 2 4
V = I R1 R1 = (1.33 A)(3 ) = 4 V
I R1
CHAPTER 9
Chapter 10
1.
Q1 (9 109 )(4 C)
= 36 103 N/C
=
2
2
r
(1 m)
(a)
E= k
(b)
E = k
Q1
(9 109 )(4 C)
= 36 109 N/C
r2
(1 mm) 2
E (1 mm): E (2 m) = 36 × 109: 36 × 103 = 1 × 106
kQ
kQ
(9 109 )(2 C)
r
=
=
= 15.81 m
E
72 N/C
r2
2.
E =
3.
C=
4.
Q = CV = (0.15 F)(45 V) = 6.75 μC
5.
a.
b.
6.
7.
8.
Q 1200 C
= 50 μF
V
24 V
1m
1"
25.4 mm
39.37"
V 500 mV
E = =
= 19.69 V/m
d 25.4 mm
25.4 mm
0.254 mm
100
V
500 mV
E = =
= 1.97 kV/m
d 0.254 mm
Q 160 C
= 23.53 V
C 6.8 F
V 23.53 V
E = =
= 4.71 kV/m
d
5 mm
V=
1m
0.1"
2.54 mm
39.37"
(0.1 m 2 )
A
= 348.43 pF
C = 8.85 1012εr = 8.85 1012(1)
2.54 mm
d
(0.1 m 2 )
A
C = 8.85 1012 εr = 8.85 1012(2.5)
= 871.06 pF
2.54 mm
d
9.
C = 8.85 1012εr
10.
C = εrCo εr =
CHAPTER 10
A
8.85 1012 (4)(0.15 m 2 )
d=
= 2.66 m
d
2 F
C
6.8 nF
= 5 (mica)
=
Co 1360 pF
111
11.
12.
C = 8.85 10-12(7)
b.
E =
c.
Q = CV = (24.78 nF)(200 V) = 4.96 C
a.
b.
c.
d.
13.
14.
15.
(0.08 m 2 )
= 24.78 nF
0.2 mm
a.
d=
V
200 V
= 106 V/m
d 0.2 mm
1
(4.7 F) = 2.35 F
2
C = 2(4.7 F) = 9.4 F
C = 20(4.7 F) = 94 F
1
(4)
3 (4.7 F) = 25.1 F
C=
1
4
C=
8.85 1012 r A (8.85 1012 )(5)(0.02 m 2 )
= 130.15 µm
6800 pF
C
106 m 39.37 in. 1000 mils
d = 130.15 µm
= 5.12 mils
1 m 1 m 1 in.
5000 V
5.12 mils
= 25.6 kV
mil
1200 V
mil
mica:
1200 V
= 0.24 mils
5000 V
5000 V
mil
1
1m
0.24 mils
= 6.10 m
1000 mils 39.37 in.
200
(22 F)/C = 4400 pF/C
1 106
4400 pF
4400 pF
[80C] = 0.35 F
[T]
C
C
16.
J = 5%, Size 40 pF 2 pF, 38 pF 42 pF
17.
F = 1%, Size 47 × 101 = 470 F ± 4.7 F, 465.3 F 474.7 F
18.
K = 10%, Size 18 × 102 pF = 1800 pF 180 pF, 1620 pF 1980 pF
19.
a.
τ
b.
C = E(1 et/τ) = 20 V(1 et/0.56 s)
112
= RC = (105 Ω)(5.6 μF) = 0.56 s
CHAPTER 10
c.
1τ = 0.632(20 V) = 12.64 V, 3τ = 0.95(20 V) = 19 V
5τ = 0.993(20 V) = 19.87 V
d.
iC =
20 V t/τ
e = 0.2 mAet/0.56 s
100 k
R = Eet/τ = 20 Vet/0.56 s
e.
20.
21.
= RC = (106 )(5.6 F) = 5.6 s
b.
υC = E(1 et/τ) = 20 V(1 et/5.6s)
d.
iC =
a.
τ
c.
1τ = 12.64 V, 3τ = 19 V, 5τ = 19.87 V
e.
Same as problem 21 with 5τ = 28 s and Im = 20 A
a.
τ
b.
C = E(1 et/τ) = 100 V(1 et/5.5 ms)
c.
1τ = 63.21 V, 3τ = 95.02 V, 5τ = 99.33 V
d.
iC =
20 V t/τ
e = 20 A et/5.6s
1M
υR = Eet/τ = 20V et/5.6s
= RC = (2.2 k + 3.3 k)1 µF = (5.5 k)(1 F) = 5.5 ms
VR2
R2
E t/τ 100 V t/τ
e = 18.18 mAet/5.5 ms
e =
RT
5.5 k
3.3 k(100 V)
= 60 V
3.3 k 2.2 k
= 60 Vet/5.5 ms
e.
CHAPTER 10
113
22.
a.
R = 68 kΩ + 22 kΩ = 90 kΩ
τ = RC = (90 k)(18 µF) = 1.62 s
b.
C = E(1 et/τ) = (20 V + 40 V)(1 et/τ)
C = 60 V(1 et/1.62s)
c.
iC =
60 V t/τ
E t/τ
e =
e = 0.67 mAet/1.62s
90 k
R
d.
23.
a.
100 μs
b.
C = 12 V(1 e50µs/100µs) = 12 V(1 e0.5) = 12 V(1 0.607)
c.
C = 12 V(1 e1ms/100µs) = 12 V(1 e10) = 12 V(1 45.4 106)
a.
c.
= 20 ms, 5 = 5(20 ms) = 100 ms
20 ms
= RC, R =
= 2 k
C 10 F
C (20 ms) = 40 mV(1 e20ms/20ms) = 40 mV(1 e1)
d.
e.
f.
C = 40 mV(1 e10) = 40 mV(1 45 106) 40 mV
Q = CV = (10 F)(40 mV) = 0.4 C
= RC = (1000 106 )(10 F) = 10 103 s
= 12 V(.393) = 4.72 V
24.
b.
12 V(999.95 × 103) 12 V
= 40 mV(1 .368) = 40 mV(0.632) = 25.28 mV
1 min 1 h
5 = 50 103 s
= 13.89 h
60 s 60 min
25.
a.
= RC = (4.7 k)(56 F) = 263.2 ms
b.
C = E(1 et/) = 22 V(1 et/263.2ms)
iC =
c.
d.
C(1 s) = 22 V(1 e1s/263.2ms) = 22 V(1 e3.8)
= 22 V(1 22.37 103) = 21.51 V
iC (1 s) = 4.68 mAe1s/263.2ms = 4.68 mA(22.37 103) = 0.105 mA
C = 21.51 Vet/263.2ms
iC =
114
22 V t / 263.2ms
E t /
e
e
= 4.68 mAet/263.2ms
R
4.7 k
21.51 V t / 263.2ms
= 4.58 mAet/263.2ms
e
4.7 k
CHAPTER 10
e.
26.
a.
= RC = (3 k + 2 k)(2 F) = 10 ms
C = 30 V(1 et/10ms)
iC =
R1
30 V t /10ms
= 6 mAt/10ms
e
5 k
= iC R1 = (6 mA)(3 k)et/10ms = 18 Vet/10ms
b.
100ms: e10 = 45.4 106
C = 30 V(1 45.4 106) = 30 V
iC = 6 mA(45.4 106) = 0.27 A
R1 = 18 V(45.4 106) = 0.82 mV
c.
200 ms: = R2C = (2 k)(2 F) = 4 ms
C = 30 Vet/4ms
30 V t / 4ms
e
= 15 mAet/4ms
2 k
At t = 0: R2 iC R2 (6 mA)(2 k)e t /10 ms
iC =
= 12 Vet/10 ms
At t = 200 ms: R2 (15 mA)(2 k)e t / 4 ms
= 30 Vet/4 ms
d.
CHAPTER 10
115
27.
a.
= RC = (220 k)(22 pF) = 4.84 s
C = 60 V 1 e t/4.84 s
iC =
b.
60 V t /
= 272.73 Ae t/4.84 s
e
220 k
= RC = (220 k + 470 kΩ)(22 pF) = (690 kΩ)(22 pF) = 15.18 s
C = 60 V(1 e5) = 60 V(1 6.73 × 103) = 59.6 V
C = 59.6 Vet/15.18μs
iC = 272.73 µAe5 = 272.73 µA(6.73 × 103) = 1.84 μA
60 V
iC(max) =
= 86.96 µA
690 k
iC = 86.96 μAet/15.18μS
c.
116
CHAPTER 10
d.
R = (470 kΩ)(86.96 µA)et/15.18ms
= 40.87Vet/15.18μs
28.
29.
a.
= RC = (2 m)(1000 F) = 2 s
5 = 10 s
b.
Im =
c.
yes
a.
C = Vf + (Vi Vf)et/
= RC = (4.7 k)(4.7 F) = 22.1 ms, Vf = 40 V, Vi = 6 V
C = 40 V + (6 V 40 V)et/22.1ms
C = 40 V 34 Vet/22.1ms
b.
Initially VR = E + C = 40 V 6 V = 34 V
V
34 V t / 22.1ms
e
= 7.23 mA et/22.1ms
iC = R e t /
R
4.7 k
V 12 V
= 6 kA
R 2 m
c.
CHAPTER 10
117
30.
= RC = (2.2 k)(2000 F) = 4.4 s
C = VCet/ = 40 Vet/4.4 s
VC t /
40 V t / 4.4 s
e
e
= 18.18 mAet/4.4 s
R
2.2 k
R = C = 40 Vet/4.4s
IC =
31.
C = Vf + (Vi Vf)et/
= RC = (820 )(3300 pF) = 2.71 s, Vf = 20 V, Vi = 10 V
C = 20 V + (10 V (20 V))et/2.71s
C = 20 V + 10 Vet/2.71s
(20 V 10 V) 10 V
= 12.2 mA
820
820
iC = iR = 12.2 mAet/2.71s
Im =
32.
118
a.
R = 10 kΩ + 8.2 kΩ = 18.2 kΩ
τ = RC = (18.2 kΩ)(6.8 µF) = 123.76 ms
C = Vf + (Vi Vf)et/τ
Vf = 20 V + 40 V = 60 V
Vi = 8 V
C = 60 V + (8 V 60 V)et/123.76 ms
C = 60 V 68 Vet/123.76 ms
8 V + 20 V + 40 V
= 3.74 mA
Im =
18.2 k
iC = 3.74 mAet/123.76 ms
CHAPTER 10
b.
33.
a.
C = 140 mV(1 e1ms/2 ms) = 140 mV(1 e0.5) = 140 mV(1 0.6065)
= 140 mV(0.3935) = 55.59 mV
b.
C = 140 mV(1 e10) = 140 mV(1 45.4 106)
c.
100 mV = 140 mV(1 et/2 ms)
0.714 = 1 et/2 ms
0.286 = et/2 ms
loge 0.286 = loge et/2 ms
1.252 = t/2 ms
t = 1.252 (2 ms) = 2.5 ms
d.
C = 138 mV = 140 mV(1 et/2 ms)
139.99 mV
0.986 = 1 et/2 ms
14 × 103 = et/2 ms
loge 14 × 103 = t/2 ms
4.268 = t/2 ms
t = (4.268)(2 ms) = 8.54 s
CHAPTER 10
119
34.
τ = RC = (33 kΩ)(20 µF) = 0.66 s
C = 12 V(1 et0.66 s)
8 V = 12 V(1 et0.66 s)
8 V = 12 V 12 Ve(1 et/0.66 s)
4 V = 12 Vet0.66 s
0.333 = et0.66 s
loge 0.333 = t/0.66 s
1.0996 = t/0.66 s
t = 1.0996(0.66 s) = 0.73 s
t = loge 1 C
E
12 V
10 s = loge 1
20 V
35.
.4
916.29 103
10 s
= 10.92 s
0.916
10.92 s
= RC R =
= 54.60 k
C 200 F
=
36.
a.
τ = RC = (12 kΩ + 8.2 kΩ)(6.8 µF) = 137.36 ms
C 60 V(1 e t / )
48 V 60 V(1 e t / )
0.8 1 e t /
0.2 e t /
log e 0.2 log e e t /
b.
c.
1.61 t /
t (1.61) (1.61)(137.36 ms) = 221.15 ms
60 V t /
E
iC e t /
e
20.2 k
R
2.97 mAe t /137.36 ms
iC(221.15 ms) = 2.97 mAe221.15 ms/137.36 ms
= 2.97 mAe1.61
= 2.97 mA (199.89 × 103)
= 0.594 mA
t = 2τ
iC = 2.97 mAe2τ/τ = 2.97 mAe2
= 0.4 mA
0.135
P = EI = (60 V)(0.4 mA) = 24 mW
120
CHAPTER 10
37.
a.
m = R = Eet/ = 60 Ve1/ = 60 Ve1
= 60 V(0.3679)
= 22.07 V
b.
c.
38.
a.
E t /
60 V 2 /
e
e
= 6 Ae2
R
10 M
= 6 A(0.1353)
= 0.81 A
iC =
C = E(1 et/)
t/2 s
50 V = 60 V(1 e )
0.8333 = 1 et/2 s
loge 0.1667 = t/2 s
t = (2 s)(1.792)
= 3.58 s
= RC = (10 M)(0.2 F) = 2 s
Thevenin’s theorem:
RTh:
ETh:
RTh = 8 k 24 k
= 6 k
ETh =
24 k(20 V)
= 15 V
24 k 8 k
= RC = (10 k)(15 F) = 0.15 s
C = E(1 et/)
= 15 V(1 et/0.15 s)
iC =
CHAPTER 10
15 V t / 0.15
E t /
e
e
= 1.5 mAet/0.15 s
R
10 k
121
b.
39.
a.
Source conversion and combining series resistors:
E = (4 mA)(6.8 kΩ) = 27.2 V
RT = 6.8 kΩ + 1.5 kΩ = 8.3 kΩ
Vf = 27.2 V, Vi = 10 V
= RC = (8.3 k)(2.2 F) = 18.26 ms
C = Vf + (Vi Vf)et/
= 27.2 V + (10 V (27.2 V))et/18.26 ms
C = 27.2 V + 37.2 Vet/18.26 ms
R(0+) = 27.2 V (27.2 V))e-t/18.26 ms = 37.2 V
37.2 V t /18.26ms
e
iC =
8.3 k
iC = 4.48 mAet/18.26 ms
122
CHAPTER 10
b.
40.
a.
RTh = 3.9 k + 0 1.8 k = 3.9 k
ETh = 36 V
= RC = (3.9 k)(20 F) = 78 ms
C = Vf + (Vi Vf)et/
= 36 V + (12 V 36 V)et/78 ms
C = 36 V 24 Vet/78 ms
R(0+) = 24 V 12 V = 24 V
24 V t/78 ms
e
iC =
3.9 k
iC = 6.15 mAet/78 ms
b.
CHAPTER 10
123
41.
Source conversion:
E = IR1 = (5 mA)(0.56 k) = 2.8 V
R = R1 + R2 = 0.56 k + 3.9 k = 4.46 k
RTh = 4.46 k 6.8 k = 2.69 k
4 V 2 .8 V
1.2 V
= 0.107 mA
I=
6.8 k 4.46 k 11.26 k
ETh = 4 V (0.107 mA)(6.8 k)
= 4 V 0.727 V
= 3.27 V
C = 3.27 V(1 et/)
= RC = (2.69 k)(20 F)
= 53.80 ms
C = 3.27 V(1 et/53.80 ms)
3.27 V t /
e
2.69 k
= 1.22 mA et/53.80 ms
iC =
42.
a.
= RC = (6.8 k)(39 F) = 265.2 ms
C = Vf + (Vi Vf)et/
= 20 V + (8 V (20 V))et/265.2 ms
C = 20 V + 12 Vet/265.2 ms
R(0 +) = +8 V 20 V = 12 V
12 V t / 265.2 ms
e
iC =
6.8 k
iC = 1.76 mAet/265.2 ms
124
CHAPTER 10
b.
43.
a.
= RThC = (1.67 M)(1 F) = 1.67 s
RTh = 2 M 10 M = 1.67 M
10 M(24 V)
ETh =
= 20 V
10 M 2 M
C = ETh(1 et/)
= 20 V(1 e4/)
= 20 V(1 e4)
= 20 V(1 0.0183)
= 19.63 V
E t /
e
R
20 V t /1.67s
3 A =
e
1.67 M
0.25 = et/1.67s
loge 0.25 = t/1.67 s
t = (1.67 s)(1.39)
= 2.32 s
iC =
c.
meter = C
C = ETh(1 et/)
10 V = 20 V(1 et/1.67s)
0.5 = 1 et/1.67s
0.5 = et/1.67s
loge 0.5 = t/1.67 s
t = (1.67 s)(0.69)
= 1.15 s
CHAPTER 10
125
44.
iC ao C
C
t
(40 V)
= 80 mA
1 ms
(0 V)
1 2 ms: iC = 2 106
= 0 mA
1 ms
(20 V)
2 3 ms: iC = 2 106
= 40 mA
1 ms
(10 V)
= 6.67 mA
3 6 ms: iC = 2 106
3 ms
(0 V)
6 9 ms: iC = 2 106
= 0 mA
3 ms
(10 V)
9 12 ms: iC = 2 106
= 6.67 mA
3 ms
0 1 ms: iC = 2 106
45.
iC ao C
C
t
(5 V )
= 1.18 A
20 s
(15 V )
20 30 s: iC = 4.7 F
= 7.05 A
10 s
(15 V )
= 7.05 A
30 40 s: iC = 4.7 F
10 s
0 20 s: iC = 4.7 F
(0 V )
=0A
10 s
(5 V )
50 55 s: iC = 4.7 F
= 4.7 A
5 s
40 50 s: iC = 4.7 F
55 s 60 s: iC = 4.7 F
126
(5 V )
= 4.7 A
5 s
CHAPTER 10
60 s 70 s: iC = 4.7 F
(0 V )
=0A
10 s
70 s 80 s: iC = 4.7 F
(10 V )
= 4.7 A
10 s
80 s 100 s: iC = 4.7 F
46.
(5 V )
= 1.175 A
20 s
t
C
C (iC )
t
C
0 4 ms: iC = 0 mA C = 0 V
(2 ms)
(40 mA) = 4 V
4 6 ms: iC = 40 mA C =
20 F
(10 ms)
6 16 ms: iC = +40 mA C =
(40 mA) = +20 V
20 F
(4 ms)
16 20 ms: iC = 120 mA C =
(120 mA) = 24 V
20 F
20 25 ms: iC = 0 mA C = 0 V
iC = C
CHAPTER 10
127
47.
48.
49.
50.
51.
6 F + 4 F = 10 µF, 8 µF + 12 µF = 20 µF
10 µF 20 F = 6.67 F
CT = 6 F 12 F = 4 F
CT = CT + 12 F = 4 F + 12 F = 16 F
6 F CT (6 F)(16 F)
CT = 6 F CT =
= 4.36 F
6 F CT
6 F 16 F
V1 = 10 V, Q1 = V1C1 = (10 V)(6 F) = 60 C
CT = 6 F 12 F = 4 F, QT = CTE = (4 F)(10 V) = 40 C
Q2 = Q3 = 40 C
Q
40 C
= 6.67 V
V2 = 2
C2
6 F
Q
40 C
V3 = 3
= 3.33 V
C3 12 F
360 µF + 200 µF = 560 µF
470 µF 560 µF = 255.53 µF
QT = Q3 = CTE = (255.53µF)(56 V) = 14.5 mC
Q 14.5 mC
= 30.4 V
V3 = 3
C3 470 F
V1 = V2 = E V3 = 56 V 30.4 V = 25.6 V
Q1 = V1C1 = (25.6 V)(360 µF) = 9.2 mC
Q2 = V2C2 = (25.6 V)(200 µF) = 5.1 mC
steady state ignore 10 kΩ resistor
330 µF + 120 µF = 450 µF
CT = 220 µF 450 µF = 147.76 µF
QT = Q1 = CTE = (147.76 µF)(20 V) = 2.96 mC
Q 2.96 mC
= 13.45 V
V1 = 1
C1 220 F
V3 = V2 = E V1 = 20 V 13.45 V = 6.55 V
Q2 = C2V2 = (330 µF)(6.55 V) = 2.16 mC
Q3 = C3V3 = (120 µF)(6.55 V) = 0.786 mC
4 k(48 V)
= 32 V = V0.08F
4 k 2 k
Q0.08F = (0.08 F)(32 V) = 2.56 C
V0.04F = 48 V
Q0.04F = (0.04 F)(48 V) = 1.92 C
52.
V4k =
53.
WC =
54.
W=
128
1
1
CV 2 (120 pF)(12 V)2 = 8,640 pJ
2
2
Q2
Q=
2C
2CW 2(6 F)(1200 J) = 0.12 C
CHAPTER 10
55.
a.
56.
a.
(220 k 3.3 k)(12 V)
= 9.85 V
2.2 k 3.3 k 1.2 k
(3.3 k)(12 V)
= 5.91 V
V100F =
2.2 k 3.3 k 1.2 k
1
W200F = (200 F)(9.85 V) 2 = 970 mJ
2
1
W100F = (100 F)(5.91 V)2 = 1.75 mJ
2
1
1
WC = CV 2 (1000 F)(100 V)2 = 5 pJ
2
2
V200F =
b.
Q = CV = (1000 F)(100 V) = 0.1 C
c.
I = Q/t = 0.1 C/(1/2000) = 200 A
d.
P = VavIav = W/t = 5 J(1/2000 s) = 10,000 W
e.
t = Q/I = 0.1 C/10 mA = 10 s
CHAPTER 10
129
Chapter 11
1.
a.
b.
c.
d.
2.
3.
4 104 Wb
= 4 102 Wb/m2 = 0.04 Wb/m2
2
A
0.01 m
0.04 T
F = NI = (40 t)(2.2 A) = 88 At
104 gauss
3
0.04 T
= 0.4 10 gauss
1
T
B=
2.54 cm 1 m
= 5.08 mm
0.2
1 100 cm
2.54 cm 1 m
= 25.4 mm
1
1 100 cm
d 2 (5.08 mm) 2
= 20.27 106 m2
A=
4
4
N 2 A (200 t) 2 (4 10 7 )(20.27 10 6 m 2 )
L=
= 40.1 H
25.4 mm
L=
b.
increase = change in µ r
Lnew = µ rLo
4.
L = N2
5.
L=
a.
b.
c.
d.
6.
130
N 2 r o A (200 t ) 2 (500)(4 10 7 )(20.27 10 6 m 2 )
= 20.06 mH
25.4 mm
a.
r o
(200 t) 2 (1000)(4 107 )(1.5 104 m 2 )
= 50.27 mH
0.15 m
N 2 r o A
L = (3)2Lo = 9Lo = 9(4.7 mH) = 42.3 mH
1
1
L = Lo = (4.7 mH) = 1.57 mH
3
3
(2)(2) 2
L =
Lo = 16 (4.7 mH) = 75.2 mH
1
2
2
1 1
(1500) Lo
2 2
L =
= 375(4.7 mH) = 1.76 mH
1
2
a.
39 102 H 10% 3900 H 10% 3.9 mH ± 10%
b.
68 × 100 H 5% = 68 F ± 5%
CHAPTER 11
c.
47 μH ± 10%
d.
15 × 102 µH ± 10% = 1500 µH ± 10% = 15 mH ± 10%
7.
e= N
d
= (50 t)(120 mWb/s) = 6.0 V
dt
8.
e= N
d
d e 20 V
= 100 mWb/s
dt
dt N 200 t
9.
1
d
1
= 14 turns
N = e
e= N
42 mV
dt
3 m Wb/s
d
dt
10.
a.
11.
b.
diL
= (22 mH)(1 A/s) = 22 mV
dt
di
e = L L = (22 mH)(1 mA/ms) = 22 mV
dt
2 mA
diL
e= L
= (22 mH)(
= 4.4 V
10 s
dt
a.
=
b.
iL =
c.
L = Eet/ = 20 Vet/15 s
R = iRR = iLR = E(1 et/) = 20 V(1 et/15 s)
d.
iL: 1 = 0.632 mA, , 3 = 0.951 mA, 5 = 0.993 mA
L: 1 = 7.36 V, 3 = 0.98 V, 5 = 140 mV
e= L
L 300 mH
= 15 s
R
20 k
E
20 mV
(1 et/)
(1 e t/ )
R
20 k
= 1 mA(1 et/15 μs)
e.
CHAPTER 11
131
12.
a.
=
L 4.7 mH
= 2.14 s
R 2.2 k
b.
iL =
E
12 V
(1 et/) = 5.45 mA(1 et/2.14 s)
(1 e t/ )
R
2.2 k
c.
L = Eet/ = 12 Vet/2.14 s
R = iRR = iLR = E(1 et/) = 12 V(1 et/2.14 s)
d.
iL: 1 = 3.45 mA, , 3 = 5.18 mA, 5 = 5.41 mA
L: 1 = 4.42 V, 3 = 0.60 V, 5 = 0.08 V
e.
18 V
(1 e t / )
RT
18V
= 1.2 kΩ
RT =
15 mA
R (15 s) 1.2 k(15 s)
L
5 15 = 15 µs: L
R
5
5
3.6 mH
13.
iL =
14.
a.
iL = If + (Ii If)et/
E
36 V
L 120 mH
= 9.23 mA, =
= 30.77 s
Ii = 8 mA, If =
R 3.9 k
R 3.9 k
iL = 9.23 mA + (8 mA 9.23 mA)et/30.77 s
iL = 9.23 mA 1.23 mAet/30.77 s
+E L R = 0 and L E R
R = iRR = iLR = (8 mA)(3.9 k) = 31.2 V
L = E R = 36 V 31.2 V = 4.8 V
L = 4.8 Vet/30.77 s
b.
132
CHAPTER 11
15.
a.
Ii = 8 mA, If = 9.23 mA, =
L 120 mH
= 30.77 s
R 3.9 k
iL = If + (Ii If)et/
= 9.23 mA + (8 mA 9.23 mA)et/30.77 s
iL = 9.23 mA 17.23 mA et/30.77 s
+E L R = 0 (at t = 0)
but, R = iRR = iLR = (8 mA)(3.9 k) = 31.2 V
L = E R = 36 V (31.2 V) = 67.2 V
L = 67.2 V et/30.77 s
b.
16.
c.
Final levels are the same. Transition period defined by 5 is also the same.
a.
Source conversion:
L
2H
= 588.2 s
R 3.4 k
iL = If + (Ii If)et/
6V
= 1.76 mA
If =
3.4 k
iL = 1.76 mA + (4 mA 1.76 mA)et/588.2s
iL = 1.76 mA + 2.24 mA et/588.2s
=
R(0 +) = 4 mA(3.4 k) = 13.6 V
KVL: +6 V 13.6 V L(0+) = 0
L(0+) = 7.6 V
t/588.2s
L = 7.6 Ve
b.
CHAPTER 11
133
17.
a.
20.8 V
= 2 mA
10.4 k
L
200 mH
τ=
=
= 19.23 s
R
10.4 k
iL = If + (Ii If )et/τ
= 2 mA + (6 mA 2 mA)et/19.23 µs
iL = 2 mA + 4 mAet/19.23 μs
If =
KVL: 20.8 V 62.4 V υL(0+) = 0
υL(0+) = 41.60 V
υL = 41.6 Ve-t/19.23 μs
b.
18.
a.
=
L = 8 Vet/0.278s, iL =
b.
134
10 mH
L
= 0.278 s
=
36 k
R
E
(1 e t/ ) = 0.222 mA(1 et/0.278s)
R
5 steady state
L
10 mH
=
= 0.208 s
R 12 k 36 k
iL = Imet/ = 0.222 mAet/0.208s
L = (0.222 mA)(48 k)et/ = 10 .66Vet/0.308s
CHAPTER 11
19.
a.
b.
L 1 mH
= 0.5 s
R 2 k
E
12 V
iL = (1 e t / )
(1 e t / ) = 6 mA(1 et/0.5s)
R
2 k
L = Eet/ = 12 V et/0.5s
=
iL = 6 mA(1 et/0.5s) = 6 mA(1 e1s/0.5s)
= 6 mA(1 e2) = 5.19 mA
L 1 mH
= 83.3 ns
=
iL = Imet/
R 12 k
iL = 5.19 mAet/83.3ns
t = 1 s: L = 12 Vet/0.5s = 12 Ve2 = 12 V(0.1353) = 1.62 V
VL = (5.19 mA)(12 k) = 62.28 V
L = 62.28 Vet/83.3ns
c.
CHAPTER 11
135
20.
a.
RTh = 6.8 k
ETh = 6 V
=
L
5 mH
= 0.74 s
R 6.8 k
E
6V
(1 e t/ )
(1 e t/ ) = 0.88 mA(1 et/0.74s)
R
6.8 k
L = Eet/ = 6 Vet/0.74s
iL =
b.
Assume steady state and IL = 0.88 mA
=
L 5 mH
= 0.33 s
R 15 k
iL = Imet/ = 0.88 mA et/0.33s
L = Vmet/
Vm = ImR = (0.88 mA)(15 k) = 13.23 V
L = 13.23 Vet/0.33s
c.
136
CHAPTER 11
d.
21.
22.
a.
VR2 max = ImR2 = (0.88 mA)(8.2 k) = 7.22 V
RTh = 2 k + 2.2 k + 6.2 k 3 kΩ = 6.22 k
6.2 k(12 V)
= 8.09 V
ETh =
6.2 k 3 k
8.09 V
L 47 mH
If =
= 7.56 s
= 1.3 mA , =
6.22 k
R 6.22 k
iL = 1.3 mA(1 et/7.56s)
L = 8.09 Vet/7.56s
b.
0.632(1.3 mA) = 0.822 mA
0.368(8.09 V) = 2.98 V
a.
Source conversion: E = IR = (4 mA)(12 k) = 48 V, ENet = 48 V 20 V = 28 V
=
iL =
L 2 mH
= 55.56 ns
R 36 k
E
28 V
(1 e t/ )
(1 e t/ ) = 0.778 mA(1 et/55.56ns)
R
36 k
L = Eet/ = 28 Vet/55.56ns
b.
t = 100 ns:
iL = 0.778 mA(1 e100ns/55.56ns) = 0.778 mA(1 e1.8) = 0.65 mA
0.165
L = 28 Ve1.8 = 4.62 V
CHAPTER 11
137
23.
RTh = 2.2 k 4.7 k = 1.50 k
4.7 k(10 V)
= 6.81 V
ETh =
4.7 k 2.2 k
L 10 mH
=
= 6.67 s
R 1.50 k
a.
E
6.81 V
(1 e t/ )
(1 e t/ ) = 4.54 mA(1 et/6.67s)
R
1.5 k
L = Eet/ = EThet/τ = 6.81 Vet /6.67s
iL =
b.
t = 10 s:
iL = 4.54 mA(1 e10s/6.67s) = 4.54 mA(1 e1.5)
= 3.53 mA
L = 6.81 V(0.223) = 1.52 V
c.
0.223
L 10 mH
= 2.13 s
R 4.7 k
iL = 3.53 mAet/2.13s
At t = 10 s
VL = (3.53 mA)(4.7 k) = 16.59 V
L = 16.59 Vet/2.13s
=
d.
24.
a.
L = Eet/
=
0 .6 H
0 .6 H
L
= 5 ms
R1 R3 100 20 120
L = 36 Vet/5 ms
L = 36 Ve25 ms/5 ms = 36 Ve5 = 36 V(0.00674) = 0.24 V
b.
138
L = 36 Ve1 ms/5 ms = 36 Ve0.2 = 36 V(0.819) = 29.47 V
CHAPTER 11
c.
E
(1 e t/ ) R1
R1 R3
R1 iR1 R1 iL R1
36 V
(1 e t/5ms ) 100
=
120
t/5 ms
))100
= (300 mA(1 e
5 ms/5 ms
) = 30 V(1 e1)
= 30 V(1 e
= 30 V(1 0.368) = 18.96 V
d.
e.
25.
a.
iL = 300 mA(1 et/5 ms)
100 mA = 300 mA(1 et/5 ms)
0.333 = 1 et/5 ms
0.667 = et/5 ms
loge 0.667 = t/5 ms
0.405 = t/5 ms
t = 0.405(5 ms) = 2.03 ms
None-In parallel with supply.
16 V
= 2 mA
4.7 k 3.3 k
t = 0 s: Thevenin:
RTh = 3.3 k + 1 k 4.7 k = 3.3 k + 0.82 k = 4.12 k
1 k(16 V)
= 2.81 V
ETh =
1 k 4.7 k
iL = If + (Ii If)et/
Ii =
2.81 V
L
2H
= 0.49 ms
= 0.68 mA, =
4.12 k
R 4.12 k
iL = 0.68 mA + (2 mA 0.68 mA)et/0.49 ms
iL = 0.68 mA + 1.32 mAet/0.49 ms
R(0+) = 2 mA(4.12 k) = 8.24 V
KVL(0+): 2.81 V 8.24 V L = 0
L = 5.43 V
L = 5.43 Vet/0.49 ms
If =
b.
CHAPTER 11
139
26.
a.
8V
= 5.33 mA, VL = 0 V
1.5 k
RTh = (3 k 12 k) 4 k 1.5 k
2.4 k(20 V)
= 7.5 V
ETh =
2.4 k 4 k
Steady-state: I L
RTh
1.5 k 1.5 k 0.75 k
ETh
8 V 7.5 V 15.5 V
L
3 mH
4 s
R 0.75 k
15.5 V
= 20.67 mA
Ii = 5.33 mA
0.75 k
iL = If + (Ii If)et/τ
= 20.67 mA + (5.33 mA 20.67 mA)et/4 µs
iL = 20.67 mA 15.34 mAet/4μs
υL = 15.5 Vet/4μs
If =
b.
iL (2 ) 20.67 mA 15.34 mA
e2
0.135
18.6 mA
L (2 ) 15.5Ve2 15.5V(0.135) = 2.09 V
c.
Ii = 18.6 mA
υL + υR 8 V = 0
υL = 8 V υR = 8 V (18.6 mA)(1.5 kΩ)
= 19.9 V
L 3 mH
= 2 µs
R 1.5 k
8V
= 5.33 mA
1.5 k
iL = If + (Ii If)et/τ = 5.33 mA + (18.6 mA 5.33 mA)et/2µs
= 5.33 mA + 13.27 mAet/2µs
υL = 19.9 Vet/2µs
Ii = 18.6 mA
140
If =
CHAPTER 11
27.
a.
RTh = 2 M 10 M = 1.67 M
10 M(24 V)
= 20 V
ETh =
10 M 2 M
ETh
20 V
= 12 μA
=
RTh 1.67 M
L
5H
5 s
Rmeter 10 M
iL = 12 Aet/5 s
10 A = 12 Aet/5 s
0.833 = et/5 s
loge 0.833 = t/5 s
0.183 = t/5 s
t = 0.183(5 s) = 0.92 s
I L (0 ) =
28.
b.
L (0+) = iL(0+)Rm = (12 A)(10 M) = 120 V
L = 120 Vet/5s = 120 Ve10s/5s = 120 Ve2 = 120 V(0.135) = 16.2 V
c.
L = 120 Ve5/ = 120 Ve5 = 120 V(6.74 103) = 0.81 V
a.
Closed Switch:
RTh = 1.2 k 2.2 k = 0.776 kΩ
1.2 k(24 V)
= 8.47 V
ETh =
1.2 k 2.2 k
CHAPTER 11
141
Open Switch:
RTh
6.9 k 1.2 k 1.02 k
1.2 k(24 V)
ETh
= 3.56 V
8.1 k
3.56 V + υR υL = 0
υL = 3.56 V + (1.09 mA)(1.02 kΩ)
= 7.57 V
υL = 7.57Vet/1.18 ms
L
1.24
= 1.18 ms
R 1.02 k
3.56 V
Iss =
= 3.49 mA = If
1.02 k
iL I f ( I i I f )e t /
3.49 mA+ ( 10.91 mA (3.49 mA) e t /1.18 ms
iL = 3.49 mA 7.42 mAet/1.18 ms
b.
29.
142
a.
iL = 100 mA(1 e1ms/20ms) = 100 mA(1 e1/20)
= 100 mA(1 e0.05) = 100 mA(1 951.23 103) = 100 mA(48.77 103)
= 4.88 mA
b.
iL = 100 mA(1 e100ms/20ms) = 100 mA(1 e5)
= 99.33 mA
c.
50 mA = 100 mA(1 et/)
0.5 = 1 et/
0.5 = et/
0.5 = et/
loge 0.5 = t/
t = ()(loge 0.5) = (20 ms)(loge 0.5) = (20 ms)(693.15 103)
= 13.86 ms
CHAPTER 11
30.
d.
99 mA = 100 mA(1 et/20 ms)
0.99 = 1 et/20ms
0.01 = et/20ms
0.01 = et/20ms
loge 0.01 = t/20 ms
t = (20 ms)(loge 0.01) = (20 ms)(4.605) = 92.1ms
a.
IL (1τ) = 0.632Imax = 126.4 µA
126.4
= 200 μA
Imax =
0.632
iL I m (1 e t / )
b.
64.4 s
160 A 200 A 1 e
0.8 1 e
0.2 e
64.4 s
64.4 s
log e 0.2 1.61
31.
64.4 s
64.4 s
40 s
1.61
L
L
40 s =
500
R
L 20 mH
c.
d.
Im
a.
L open circuit equivalent
10 M(16 V)
= 13.33 V
VL =
10 M 2 M
E
E (200 A)(500 ) 100 mV
R
b.
RTh = 2 M 10 M = 1.67 M
10 M(16 V)
= 13.33 V
ETh =
10 M 2 M
I Lfinal
CHAPTER 11
ETh 13.33 V
= 7.98 A
RTh 1.67 M
143
iL = 7.98 A(1 et/3 s)
c.
10 A = 7.98 A(1 et/3 s)
1.253 = 1 et/3 s
0.253 = et/3 s
loge(0.253) = t/3s
1.374 = t/3s
t = 1.374(3 s) = 4.12 s
d.
=
L
5H
= 3 s
R 1.67 M
L = 13.33 V et/3 s = 13.33 V e12 s/3 s = 13.33 V e4
= 13.33 V(0.0183) = 0.244 V
32.
eL = L
i
:
t
15 mA
0 2 ms, eL = (200 mH)
= 1.5 V
2 ms
45 mA
= 0.75 V
2 14 ms, eL = (200 mH)
12 ms
15 ms
= 3 V
14 15 ms, eL = (200 mH)
1 ms
15 19 ms, eL = 0 V
15 mA
19 22 ms, eL = (200 mH)
= 1 V
3 ms
22 24 ms, eL = 0 V
33.
L = L
i L
t
15 mA
= 37.5 mV
0 2 ms: L = (5 mH)
2 ms
30 mA
= 37.5 mV
2 6 ms: L = (5 mH)
4 ms
15 mA
6 9 ms: L = (5 mH)
= 25 mV
3 ms
9 13 ms: L = 0 V
5 mA
13 14 ms: L = (5 mH)
= 25 mV
1 ms
14 17 ms: L = 0 V
144
CHAPTER 11
5 mA
= 12.5 mV
17 19 ms: L = (5 mH)
2 ms
34.
L = 10 mH, 4 mA at t = 0 s
i
t
L = L i L
t
L
0 5 s: L = 0 V, iL = 0 mA and iL = 4 mA
5 s
(10 V) = 5 mA
5 10 s: iL =
10 mH
2 s
10 12 s: iL =
(+60 V) = +12 mA
10 mH
12 16 s: L = 0 V, iL = 0 mA and iL = 11 mA
8 s
10 V = 8 mA
16 24 s: iL =
10 mH
35.
a.
L3 L4 = 3.5 mH 5.6 mH = 1.953 mH
L2 + L3 L4 = 3.3 mH + 1.953 mH = 5.253 mH
L = L1 (L2 + L3 L4) = 2.4 mH 5.253 mH = 1.647 mH
LT = L4 + L = 9.1 mH + 1.647 mH
LT = 10.75 mH
36.
L2 L3 = 10 mH 30 mH = 7.5 mH
L = L1 + L2 L3 = 47 mH + 7.5 mH = 54.5 mH
L L4 = 54.5 mH 22 mH = 15.67 mH
CHAPTER 11
145
37.
33 mH + 1.8 mH = 5.1 mH
4.7 mH 5.1 mH = 2.45 mH
38.
LT = 6.2 mH + 12 mH 36 mH + 24 mH = 39.2 mH
CT = 9.1 F + 10 F 91 F = 9.1 F + 9.01 F = 18.11 F
39.2 mH in series with 18.11 F
39.
7 µF 42 µF = 6 µF
12 µF + 6 µF = 18 μF
5 mH + 20 mH = 25 mH
Series combination of 2.2 kΩ resistor, 25 mH coil, 18 µF capacitor
40.
a.
RT = 2 k 8.2 k = 1.61 k, LT = 3 mH 2 mH = 1.2 mH
L 1.2 mH
= 745.3 µs
= T
RT 1.61 k
E
iL =
(1 e t / )
RT
36 V
(1 e t / 745.3 s ) = 22.36 mA(1 et/745.3µs)
1.61 k
L = Eet/ = 36 Ve t/745.3µ s
=
b.
146
CHAPTER 11
41.
a.
Source conversion: E = 16 V, Rs = 2 k
RTh = 2 k + 2 k 8.2 k = 2 k + 1.61 k = 3.61 k
8.2 k(16 V)
= 12.86 V
ETh =
8.2 k 2 k
E
12.86 V
L 30 mH
= 8.31 s
Im = Th
3.56 mA, =
RTh 3.61 k
R 3.61 k
iL = 3.56 mA(1 et/8.31s)
L1 L2 = 12.86 V initially (t = 0+)
L
10 mH
1
of total = (12.86 V) = 4.29 V
10 mH +20 mH
3
L = 4.29 Vet/8.31μs
b.
42.
a.
RTh = 10 k 20 k = 6.67 k
20 k(20 V)
ETh =
= 13.33 V
20 k 10 k
LT = 3 H + 4.7 H 10 H = 3 H + 3.197 H = 6.197 H
L
6.197 H
= 0.93 ms
τ= T =
R 6.67 k
υL = 13.33Vet/0.93 ms
13.33 V
(1 et/τ) = 2 mA(1 et/0.93 ms)
iL =
6.67 k
CHAPTER 11
147
b.
c.
3.197 H
0.52 L
3 H + 3.197 H
= (0.52)(13.33et/0.93 ms) = 6.93 Vet/0.93 ms
L3 =
L3
43.
44.
45.
E 20 V
=5A
4
R1
20 V
20 V
E
I2 = I R2
=2A
R2 R3 6 4 10
I1 = I R1 + I2 = 5 A + 2 A = 7 A
I R1
I1 = I2 = 0 A
V1 = V2 = E = 60 V
12 V
= 3 A, I2 = 0 A
4
V1 = 12 V, V2 = 0 V
I1 =
46.
6 V)
= 10.34 V
6 20 3
(3 6 )(50 V)
V1 =
= 15.52 V
29
50 V
I1 =
= 1.72 A
20 3 6
I2 = 0 A
V2 =
148
CHAPTER 11
Chapter 12
Φ:
1.
CGS: 5 104 Maxwells, English: 5 104 lines
B: CGS: 8 Gauss, English: 51.62 lines/in.2
2.
Φ:
3.
a.
B=
4 104 Wb
= 0.04 T
=
A
0.01 m 2
4.
a.
R=
0.06 m
300
l
=
=
4
2
A 2 10 m
m
b.
R=
l
0.0762 m
152.4
=
=
4
2
A 5 10 m
m
c.
R=
0.1 m
1000
l
=
=
4
2
A 1 10 m
m
SI 6 104 Wb, English 60,000 lines
B: SI 0.465 T, CGS 4.65 103 Gauss, English 30,000 lines/in.2
from the above R (c) > R (a) > R (b)
5.
R=
F
400 At
=
= 952.4 103 At/Wb
4.2 104 Wb
6.
R=
F
120 gilberts
= 1.67 103 rels (CGS)
=
72,000 maxwells
7.
1m
= 0.1524 m
6 in.
39.37 in .
F
400 At
= 2624.67 At/m
H= =
l 0.1524 m
8.
µ=
9.
B=
2 B 2(1200 104 T)
= 4 104 Wb/Am
=
H
600 At/m
10 104 Wb
= 0.33 T
=
A
3 103 m 2
Fig. 12.7: H 800 At/m
NI = Hl I = Hl/N = (800 At/m)(0.2 m)/75 t = 2.13 A
CHAPTER 12
149
10.
11.
12.
3 104 Wb
=
= 0.6 T
A 5 104 m 2
Fig. 12.7, Hiron = 2500 At/m
Fig. 12.8, Hsteel = 70 At/m
NI = Hl(iron) + Hl(steel)
(100 t)I = (Hiron + Hsteel)l
(100 t)I = (2500 At/m + 70 At/m)0.3 m
771 A
= 7.71 A
I=
100
B=
a.
N1I1 + N2I2 = Hl
12 104 Wb
B= =
=1T
A 12 104 m 2
Fig. 12.7: H 750 At/m
N1(2 A) + 30 At = (750 At/m)(0.2 m)
N1 = 60 t
b.
μ=
a.
B
1T
= 13.34 104 Wb/Am
=
H 750 At/m
1 Wb
80,000 lines 8
= 8 104 108 Wb = 8 104 Wb
10 lines
1m
= 0.14 m
l(cast steel) = 5.5 in.
39.37 in .
1m
l(sheet steel) = 0.5 in.
= 0.013 m
39.37 in .
1m 1m
= 6.45 104 m2
Area = 1 in.2
39.37
in
.
39.37
in.
8 104 Wb
= 1.24 T
=
A 6.45 104 m 2
Fig 12.8: Hsheet steel 460 At/m, Fig. 12.7: Hcast steel 1275 At/m
NI = Hl(sheet steel) + Hl(cast iron)
= (460 At/m)(0.013 m) + (1275 At/m)(0.14 m)
= 5.98 At + 178.50 At
NI = 184.48 At
B=
b.
150
B
1.24 T
= 9.73 104 Wb/Am
=
H 1275 At/m
B
1.24 T
Sheet steel: μ =
= 26.96 104 Wb/Am
=
H 460 At/m
Cast steel: μ =
CHAPTER 12
13.
N1I + N2 =
+ Hl
Hl
cast steel cast iron
(20 t)I + (30 t)I = "
(50 t)I = "
B=
1m 1m
with 0.25 in.2
= 1.6 104 m2
A
39.37 in . 39.37 in.
0.8 104 Wb
= 0.5 T
1.6 104 m 2
Fig. 12.8: Hcast steel 280 At/m
Fig. 12.7: Hcast iron 1500 At/m
1m
lcast steel = 5.5 in.
= 0.14 m
39.37 in .
B=
1m
= 0.064 m
lcast iron = 2.5 in.
39.37 in .
(50 t)I = (280 At/m)(0.14 m) + (1500 At/m)(0.064 m)
50I = 39.20 + 96.00 = 135.20
I = 2.70 A
14.
15.
a.
lab = lef = 0.05 m, laf = 0.02 m, lbc = lde = 0.0085 m
NI = 2Hablab + 2Hbclbc + Hfalfa + Hglg
2.4 104 Wb
= 1.2 T H 360 At/m (Fig. 12.8)
B= =
A
2 104 m 2
100I = 2(360 At/m)(0.05 m) + 2(360 At/m)(0.0085 m)
+ (360 At/m)(0.02 m) + 7.97 105(1.2 T)(0.003 m)
= 36 At + 6.12 At + 7.2 At + 2869 At
100I = 2918.32 At
I 29.18 A
b.
air gap: metal = 2869 At:49.72 At = 58.17:1
B
1.2 T
= 3.33 103 Wb/Am
=
μsheet steel =
H 360 At/m
μair = 4π 107 Wb/Am
μsheet steel: μair = 3.33 103 Wb/Am:4 107 2627:1
1m
4 cm
= 0.04 m
100 cm
(8 104 Wb 0.5 104 Wb) 36(7.5 104 )
1
d 1
= (80 t)(0.9 A)
=
f = NI
1
0.02
2
dx 2
(0.04 m)
2
= 1.35 N
CHAPTER 12
151
16.
C = 2πr = (6.28)(0.3 m) = 1.88 m
2 104 Wb
B= =
= 1.54 T
A 1.3 104 m 2
Fig. 12.7: Hsheet steel 2100 At/m
Hg = 7.97 105Bg = (7.97 105)(1.54 T) = 1.23 106 At/m
N1I1 + N2I2 = Hglg + Hl(sheet steel)
(200 t)I1 + (40 t)(0.3 A) = (1.23 106 At/m)(2 mm) + (2100 At/m)(1.88 m)
I1 = 31.98 A
17.
a.
1m
= 2 103 m
0.2 cm
100 cm
d 2 (3.14)(0.01 m) 2
= 0.79 104 m2
A=
=
4
4
NI = Hglg, Hg = 7.96 105 Bg
0.2 104 Wb
2 103 m
(200 t)I = (7.96 105 )
4
2
0.79 10 m
I = 2.02 A
b.
18.
2 104 Wb
= 0.25 T
=
A 0.79 104 m 2
2
1 Bg A 1 (0.25 T ) 2(0.79 104 m 2 )
F
=
2 o
2
4 107
2N
Bg =
Table:
Section
Φ(Wb)
ab, gh
4
bc, fg
2 10
cd, ef
2 104
152
2 10
4
H
l(m)
5 10
0.2
5 10
4
0.1
5 104
5 10
Hl
0.099
4
0.2
4
0.2
4
0.002
2 10
bg
B(T)
4
5 10
ah
de
A(m2)
CHAPTER 12
2 104 Wb
= 0.4 T
=
A 5 104 m 2
Air gap: Hg = 7.97 105(0.4 T) = 3.19 105 At/m
Hglg = (3.19 105 At/m)(2 mm) = 638 At
Fig 12.8: Hbc = Hcd = Hef = Hfg = 55 At/m
Hbclbc = Hfglfg = (55 At/m)(0.1 m) = 5.5 At
Hcdlcd = Heflef = (55 At/m)(0.099 m) = 5.45 At
Bbc = Bcd = Bg = Bef = Bfg =
For loop 2: F = 0
Hbclbc + Hcdlcd + Hglg + Heflef + Hfglfg Hgblgb = 0
5.5 At + 5.45 At + 638 At + 5.45 At + 5.50 At Hgblgb = 0
Hgblgb = 659.90 At
659.90 At
= 3300 At/m
and Hgb =
0.2 m
Fig 12.7: Bgb 1.55 T
with Φ2 = BgbA = (1.55 T)(2 104 m2) = 3.1 104 Wb
ΦT = Φ1 + Φ2
= 2 104 Wb + 3.1 104 Wb
= 5.1 104 Wb = Φab = Φha = Φgh
5.1 104 Wb
= 1.02 T
Bab = Bha = Bgh = T =
A
5 104 m 2
BH curve: (Fig 12.8):
Hab = Hha = Hgh 180 At/m
Hablab = (180 At/m)(0.2 m) = 36 At
Hhalha = (180 At/m)(0.2 m) = 36 At
Hghlgh = (180 At/m)(0.2 m) = 36 At
which completes the table!
Loop #1: F = 0
NI = Hablab + Hbglbg + Hghlgh + Hahlah
(200 t)I = 36 At + 659.49 At + 36 At + 36 At
(200 t)I = 767.49 At
I 3.84 A
19.
NI = Hl
l = 2πr = (6.28)(0.08 m) = 0.50 m
(100 t)(2 A) = H(0.50 m)
H = 400 At/m
Fig. 12.8: B 0.68 T
Φ = BA = (0.68 T)(0.009 m2)
Φ = 6.12 mWb
CHAPTER 12
153
20.
NI = Hab(lab + lbc + lde + lef + lfa) + Hglg
300 At = Hab(0.8 m) + 7.97 105 Bg(0.8 mm)
300 At = Hab(0.8 m) + 637.6 Bg
Assuming 637.6 Bg Hab(0.8 m)
then 300 At = 637.6 Bg
and Bg = 0.47 T
Φ = BA = (0.47 T)(2 104 m2) = 0.94 104 Wb
Bab = Bg = 0.47 T H 270 At/m (Fig. 12.8)
300 At = (270 At/m)(0.8 m) + 637.6(0.47 T)
300 At 515.67 At
Poor approximation!
300 At
100% 58%
515.67 At
Reduce Φ to 58%
0.58(0.94 104 Wb) = 0.55 104 Wb
0.55 104 Wb
= 0.28 T H 190 At/m (Fig. 12.8)
B= =
A
2 104 m 2
300 At = (190 At/m)(0.8 m) + 637.6(0.28 T)
300 At 330.53 At
Reduce Φ another 10% = 0.55 104 Wb 0.1(0.55 104 Wb)
= 0.495 104 Wb
0.495 104 Wb
B= =
= 0.25 T H 175 At/m (Fig. 12.7)
A
2 104 m 2
300 At = (175 At/m)(0.8) + 637.6(0.28 T)
300 At 318.53 At but within 5% OK
Φ 0.55 104 Wb
21.
a.
1τ = 0.632 Tmax
Tmax 1.5 T for cast steel
0.632(1.5 T) = 0.945 T
At 0.945 T, H 700 At/m (Fig. 12.7)
B = 1.5 T(1 eH/700 At/m)
b.
H = 900 At/m:
B = 1.5 T 1 e
900 At/m
700 At/m
Graph: 1.1 T
H = 1800 At/m:
= 1.09 T
1800 At/m
B = 1.5 T 1 e 700 At/m = 1.39 T
Graph: 1.38 T
H = 2700 At/m:
B = 1.5 1 e
2700 At/m
700 At/m
= 1.47 T
Graph: 1.47 T
Excellent comparison!
154
CHAPTER 12
c.
B = 1.5 T(1 eH/700 At/m) = 1.5 T 1.5 TeH/700 At/m
B 1.5 T = 1.5 TeH/700 At/m
1.5 B = 1.5 TeH/700 At/m
1.5 T B
= eH/700 At/m
1.5 T
B
H
loge 1
=
1.5 T 700 At/m
B
and H = 700 loge 1
1.5 T
d.
B = 1 T:
1T
H = 700 loge 1
= 769.03 At/m
1.5 T
Graph: 750 At/m
B = 1.4 T:
1.4 T
H = 700 loge 1
= 1895.64 At/m
1.5 T
Graph: 1920 At/m
e.
B
H = 700 loge 1
1.5 T
0.2 T
= 700 loge 1
1.5 T
= 100.2 At/m
Hl (100.2 At/m)(0.16 m)
= 40.1 mA
I=
=
N
400 t
vs 44 mA for Ex. 12.1
CHAPTER 12
155
Chapter 13
1.
a.
b.
c.
d.
e.
10 V
15 ms: 10 V, 20 ms: 0 V
20 V
20 ms
2 cycles
2.
a.
b.
c.
d.
e.
200 μA
1 s: 200 μA, 7 s: 200 µA
400 μA
4 s
2.5 cycles
3.
a.
b.
c.
d.
e.
40 mV
1.5 ms: 40 mV, 5:1 ms: 40 mV
80 mV
2 ms
3.5 cycles
4.
a.
T=
b.
c.
d.
5.
a.
b.
c.
d.
1
f
1
T=
f
1
T=
f
1
T=
f
1
= 5 ms
200 Hz
1
= 25 ns
40 MHz
1
= 50 s
20 kHz
1
=1s
1 Hz
1 1
= 1 Hz
T 1s
1
1
f=
= 16 Hz
1
T
s
16
1
1
f=
= 25 Hz
T 40 ms
1
1
= 40 kHz
f=
T 25 s
f=
6.
T=
1
= 1 ms, 5(1 ms) = 5 ms
1 kHz
7.
T=
24 ms
= 0.3 ms
80 cycles
156
CHAPTER 13
42 cycles
= 7 Hz
6s
8.
f=
9.
a.
Vpeak = (2.5 div.)(50 mV/div) = 125 mV
b.
T = (3.2 div.)(10 s/div.) = 32 s
c.
f=
a.
Radians =
40 = 0.22 π rad
180
10.
b.
c.
11.
Radians =
170 = 0.94 rad
180
a.
180
= 60
Degrees =
3
b.
180
Degrees =
1.2 = 216
d.
a.
b.
c.
d.
13.
Radians =
60 = rad
3
180
Radians =
135 = 0.75 rad
180
d.
c.
12.
1
1
= 31.25 kHz
T 32 s
a.
b.
c.
d.
180 1
Degrees =
= 18
10
180
Degrees =
0.6 = 108
2
2
= 3.49 rad/s
T 1.8 s
2
=
= 20.94 103 rad/s
3
0.3 10 s
2
= 785.4 103 rad/s
=
8 106 s
2
= 1.57 × 106 rad/s
=
6
4 10 s
=
= 2 f = 2 (100 Hz) = 628.32 rad/s
= 2 f = 2 (0.25 kHz) = 1.57 × 103 rad/s
= 2 f = 2 (2 kHz) = 12.56 103 rad/s
= 2 f = 2 (0.004 MHz) = 25.13 103 rad/s
CHAPTER 13
157
14.
15.
a.
2
f=
T
2
2 1
T=
f
754 rad/s
= 120 Hz, T = 8.33 ms
f=
2
2
= 2 f =
b.
f=
12 rad/s
= 1.91 Hz, T = 523.6 ms
2
2
c.
f=
6000 rad/s
= 954.93 Hz, T = 1.05 ms
2
2
d.
f=
0.16 rad/s
= 25.46 103 Hz, T = 39.28 ms
2
2
(60)
radians
180 3
t=
/ 3 rad
/ 3 rad
1
1
= 2.78 ms
2 f
2 (60 Hz) (6)(60) 360
16.
/6
= 104.7 rad/s
(30)
, = t =
t 5 10 3 s
180 6
17.
a.
Amplitude = 20, f =
b.
Amplitude = 12, f = 120 Hz
10,000 rad/s
= 1591.55 Hz
Amplitude = 106, f =
2
2
10,058 rad/s
= 1.6 kHz
Amplitude = 8, f =
2
2
c.
d.
377 rad/s
= 60 Hz
2
2
18.
19.
20.
T=
21.
i = 0.5 sin 72 = 0.5(0.9511) = 0.48 A
22.
158
2
2
1
= 40 ms, cycle = 20 ms
157
2
180
1.2
= 216
= 20 sin 216 = 20(0.588) = 11.76 V
CHAPTER 13
23.
24.
6 103 = 30 103 sin
0.2 = sin
= sin1 0.2 = 11.54 and 180 11.54 = 168.46
= Vm sin
30 1 ms
360
T
360
T = 1 ms
= 12 ms
30
1
1
= 83.33 Hz
f=
T 12 10 3 s
= 2 f = (2)(83.33 Hz) = 523.58 rad/s
40 = Vm sin 30 = Vm (0.5)
40
= 80 V
Vm =
0 .5
and = 80 sin 523.58t
25.
26.
27.
a.
= 6 × 103 sin (2π 2000t + 30)
b.
i = 20 103 sin(2π 60t 60)
28.
a.
= 120 106 sin(2π 1000t 80)
29.
= 12 103 sin(2π 2000t + 135°)
30.
= 8 103 sin(2π 500t +π/6)
31.
leads i by 90
32.
i leads by 40
33.
= 2 sin (t 30 + 90)
i = 5 sin(t + 60)
+60
in phase
34.
= 4 sin(t + 90 + 90 + 180 = 4 sint
i = sin(t + 10 + 180) = sin(t + 190)
35.
T=
1
1
= 1 ms
f 1000 Hz
t1 =
120 T 2 1 ms 1
= ms
180 2 3 2
3
CHAPTER 13
i leads by 190
159
36.
2 f
T
2
2
T
2
125.66 s
50,000 rad/s
40
40
(T )
(125.66 s)
360
360
13.96 s
t1
37.
T = 1 ms
tpeak @ 30°
30
1
tpeak =
(T ) ms
360
12
38.
a.
T = ( 8 div.)(1 ms/div.) = 8 ms (both waveforms)
b.
f=
c.
Peak = (2.5 div)(0.5 V/div.) = 1.25 V
Vrms = 0.707(1.25 V) = 0.884 V
d.
Phase shift = 4.6 div., T = 8 div.
4.6 div.
=
360 = 207 i leads e
8 div.
or e leads i by 153
39.
40.
1
1
= 125 Hz (both)
T 8 ms
0 (6 V)(5 ms) (3 V)(10 ms) (3 V)(10 ms)
30 ms
30 V +30 V 30 V
1V
30
G
1
1
2 (4 ms)(20 mA) (2 ms)(8 mA) 2 (2 ms)(8 mA)
G
8 ms
40 mA 16 mA 8 mA 16 mA
8
8
= 2 mA
(35 V)(5 ms)
41.
G
1
2
(20 V)(20 ms) (20 V)(15 ms)
1
(20 V)(7.5 ms)
2
75 ms
1
2
(20 V)(7.5 ms)
1
2
(20 V)(15 ms) + 0
175 V 200 V 300 V 75 V 75 V 150 V
75
400 V 575 V
2.33 V
75
160
CHAPTER 13
42.
43.
1
1
0 (30 mA)(3 ms) (20mA)(2 ms)
2
2
G
7 ms
45 mA 20 mA
3.57 mA
7
a.
b.
c.
44.
45.
1
1
(4 V)(5 ms) (8 V)(5 ms) (8 V)(5 ms) (4 V)(5 ms) (8 V)(5 ms) (8 V)(5 ms)
2
2
G
25 ms
20 V 20 V 40 V 20 V 20 V 40 V
25
= 0V
The same
1
1
( r 2 ) ( 202 ) 628.32
2
2
628.32 628.32
15.71 15.71 mA
Area =
d
40
(15.71mA)( ) (5 mA)( )
G
2
5.36 mA
Area =
c.
T = ( 2 div.)(0.2 ms/div) = 0.4 ms
1
1
= 2.5 kHz
f=
T 0.4 ms
Average = (2.5 div.)(10 mV/div.) = 25 mV
a.
T = (4 div.)(10 s/div.) = 40 s
b.
f=
c.
G=
a.
b.
46.
0V
1
1
= 25 kHz
T 40 s
( 2.5 div.)(1.5 div.) (1 div.)(0.5 div.) (1 div.)(0.6 div.) (2.5 div.)(0.4 div.)(1 div.)(1 div.)
4 div.
3.75 div. 0.5 div. 0.6 div. 1 div. 1 div.
4
6.85 div.
=
= 1.713 div.
4
1.713 div.(10 mV/div.) = 17.13 mV
=
47.
a.
b.
c.
Vrms = 0.7071(120 V) = 84.85 V
Irms = 0.7071(6 mA) = 4.24 mA
Vrms = 0.7071(8 V) = 5.66 V
CHAPTER 13
161
48.
a.
b.
c.
= 6.79 sin 377t
i = 70.7 103 sin 377t
= 2.83 103 sin 377t
49.
Vrms =
50.
Vrms =
=
51.
G=
a.
(3 V) 2 (2 s) (2 V)2 (2 s) 0 (1 V) 2 (2 s) ( 3 V) 2 (2 s) ( 2 V)2 (2 s)
12 s
54 2
V 4.5 V 2 = 2.12 V
12
(8 V)(4 ms) (8 V)(4 ms)
0
=0V
8 ms
8 ms
Vrms =
52.
1
( 2 V)2 (4 s) (2 V)2 (1 s) (3 V)2 s
2
= 1.43 V
12 s
(8 V) 2 (4 ms) ( 8 V) 2 (4 ms)
=8V
8 ms
T = (4 div.)(10 s/div.) = 40 s
1
1
= 25 kHz
f=
T 40 s
Av. = (1 div.)(20 mV/div.) = 20 mV
Peak = (2 div.)(20 mV/div.) = 40 mV
rms =
b.
162
2
(40 mV)2
Vmax
(20 mV)2
= 34.64 mV
2
2
T = (2 div.)(50 s) = 100 s
1
1
f=
= 10 kHz
T 100 s
Av. = (1.5 div.)(0.2 V/div.) = 0.3 V
Peak = (1.5 div.)(0.2 V/div.) = 0.3 mV
rms =
53.
V02
V02
2
(.3 V)2
Vmax
(.3 V)2
= 367.42 mV
2
2
a.
CHAPTER 13
1
1
(2)(16) (2)(16) (2)(48) 96
2
2
Area = 96 + (4)(64) + (2)(4) = 96 + 256 + 8 = 360
b.
c.
d.
54.
A1 =
rms =
360
30 = 5.48
12
1
(4)(8) 4(8) 2(2)
16 32 4
= 3.67
G= 2
12
12
e.
rms 1.5 (average value)
a.
Vdc = IR = (4 mA)(2 k) = 8 V
Meter indication = 2.22(8 V) = 17.76 V
b.
Vrms = 0.707(16 V) = 11.31 V
CHAPTER 13
163
Chapter 14
1.
2.
3.
a.
(377)(10) cos 377t = 3770 cos 377t
b.
(200)(0.6) cos(754t + 20) = 120 cos(754t + 20)
c.
( 2 20)(157) cos(157t 20) = 4440.63 cos(157t 20)
d.
(200)(1) cos(t + 180) = 200 cos(t + 180) = 200 cos t
a.
Im = Vm/R = 150 V/3 Ω = 50 A, i = 50 sin 200t
b.
Im = Vm/R = 30 V/3 Ω = 10 A, i = 10 sin(377t + 20)
c.
Im = Vm/R = 6 V/3 Ω = 2 A, i = 2 sin(ωt + 100)
d.
Im = Vm/R = 12 V/3 Ω = 4 A, i = 4 sin(ωt + 220)
a.
Vm = ImR = (0.1 A)(7 103 Ω) = 700 V
υ = 700 sin 1000t
b.
Vm = ImR = (2 103 A)((7 103 Ω) = 14.8 V
υ = 14.8 sin(400t 120)
a.
0
b.
XL = 12.56f = 12.56(60 Hz) = 753.6
c.
XL = 12.56f = 12.56(4 kHz) = 50.24 k
d.
XL = 12.56f = 12.56(1.2 MHz) = 15.07 M
a.
L=
XL
2 k
=
= 22 mH
2 f 2 (14.47 kHz)
b.
L=
XL
40 k
= 1.2 H
=
2 f 2 (5.3 kHz)
a.
XL = 2πfL f =
4.
5.
6.
7.
8.
f=
164
XL
XL
XL
=
=
2 L (6.28)(1 mH) 6.28 10 3 H
10
= 1.59 kHz
6.28 103 H
CHAPTER 14
9.
10.
b.
f=
4 k
XL
= 636.94 kHz
3
6.28 10 H 6.28 10 3 H
c.
f=
12 k
XL
= 1.91 MHz
3
6.28 10 H 6.28 10 3 H
a.
Vm = ImXL = (5 A)(20 ) = 100 V
υ = 100 sin(ωt + 90)
b.
Vm = ImXL = (40 103 A)(20 ) = 0.8 V
υ = 0.8 sin(ωt + 150)
c.
i = 6 sin(ωt + 150), Vm = ImXL = (6 A)(20 ) = 120 V
υ = 120 sin(ωt + 240) = 120 sin(ωt 120)
a.
b.
11.
12.
XL = ωL = (400 rad/s)(0.1 H) = 40
Vm = ImXL = (5 106 A)(40 ) = 200 µV
υ = 200 106 sin(400t + 110)
a.
Im =
Vm 120 V
= 2.4 A, i = 2.4 sin(ωt 90)
=
X L 50
b.
Im =
Vm 30 V
= 0.6 A, i = 0.6 sin(ωt 70)
=
X L 50
a.
b.
13.
XL = ωL = (100 rad/s)(0.1 H) = 10
Vm = ImXL = (10 A)(10 ) = 100 V
υ = 100 sin(100t + 90)
XL = ωL = (60 rad/s)(0.2 H) = 12
Im = Vm/XL = 1.5 V/12 = 0.125 A
i = 0.125 sin(60t 90)
XL = ωL = (10 rad/s)(0.2 H) = 2
Im = Vm/XL = 16 mV/2 = 8 mA
i = 8 103 sin(t + 2 90) = 8 103 sin(t 88)
a.
XC =
1
1
=
=
2 fC 2 (0 Hz)(5 10 6 F)
b.
XC =
1
1
= 530.79
=
2 fC 2 (60 Hz)(5 106 F)
c.
XC =
1
1
= 15.92
=
2 fC 2 (2 kHz)(5 106 F)
CHAPTER 14
165
d.
XC
14.
15.
16.
17.
XC =
1
1
C
2 fC
2 fX C
1
2 (265 Hz)(60 )
10 F
a.
C
b.
C
a.
f=
1
1
= 4.08 kHz
=
2 CX C 2 (3.9 10 6 F)(10 )
b.
f=
1
1
= 34 Hz
=
2 CX C 2 (3.9 10 6 F)(1.2 k)
c.
f=
1
1
= 408.1 kHz
=
2 CX C 2π(3.9 10 6 F)(0.1 )
d.
f=
1
1
= 20.40 Hz
=
6
2 CX C 2 (3.9 10 F)(2000 )
1
2 (34 kHz)(1.2 k)
3900 pF
Im = Vm/XC = 120 V/2.5 = 48 A
i = 48 sin(ωt + 90)
a.
b.
Im = Vm/XC = 4 × 103 V/2.5 = 0.16 A
i = 1.6 × 103 sin(ωt + 130)
a.
υ = 30 sin 200t, XC =
Im =
b.
1
1
= 5 k
=
ωC (200)(1 106 F)
Vm 30 V
= 6 mA, i = 6 103 sin(200t + 90)
=
X C 5 k
υ = 60 103 sin 377t, XC =
Im =
166
1
1
= 62.83
=
6
2 fC 2 (2 10 Hz)(5 106 F)
1
1
= 2.65 k
=
ωC (377)(1 106 )
3
V m 60 10 V
=
= 22.64 A, i = 22.64 106 sin(377t + 90)
2,650
XC
CHAPTER 14
18.
Vm = ImXC = (50 103 A)(10 ) = 0.5 V
υ = 0.5 sin(ωt 90)
a.
19.
b.
Vm = ImXC = (2 106)(10 ) = 20 V
υ = 20 106 sin(ωt 30)
a.
i = 0.2 sin 300t, XC =
1
1
= 5.952 k
ωC (300)(0.56 106 F)
Vm = ImXC = (0.2 A)(5.952 kΩ) = 1190.48 V, υ = 1190.48 sin(300t 90)
b.
i = 8 103 sin (377t 30°), XC =
1
1
= 4.737 k
ωC (377)(0.56 106 F)
Vm = ImXC = (8 103 A)(4.737 k) = 37.81 V
υ = 37.81 sin(377t 120)
20.
21.
a.
υ leads i by 90 L, XL = Vm/Im = 550 V/11 A = 50
X
50
= 132.63 mH
L= L=
ω 377 rad/s
b.
υ leads i by 90 L, XL = Vm/Im = 36 V/4 A = 9
1
1
L=
= 147.36 μH
=
ωX L (754 rad/s)(9 )
c.
υ and i are in phase R
V
10.5 V
=7
R= m=
I m 1.5 A
a.
b.
c.
22.
i = 5 sin(ωt + 90)
i leads by 90 C
= 2000 sin ωt
Vm 2000 V
= 400
XC =
=
5A
Im
i = 2 sin(157t + 60)
leads i by 90 L
= 80 sin(157t + 150)
V
80 V
40
= 40 Ω, L = X L =
= 254.78 mH
XL = m =
ω 157 rad/s
Im 2 A
= 35 sin(ωt 20)
in phase R
i = 7 sin(ωt 20)
Vm 35 V
=5
R=
=
Im 7 A
CHAPTER 14
167
23.
24.
1
1
1
1
=R f =
=
=
3
6
2 fC
2 RC 2 (2 10 )(1 10 F) 12.56 103
79.62 Hz
XC =
25.
XL = 2πfL = R
R
10,000
= 318.47 mH
L=
=
2 f 2 (5 103 Hz)
26.
XC = XL
1
2 fL
2 fC
1
f2 =
4 2 LC
1
1
= 1.59 kHz
=
and f =
3
2 LC 2 (10 10 H)(1 106 F)
27.
XC = XL
1
1
1
= 2 fL C = 2 2 =
= 5.07 nF
2 fC
4 f L 4(9.86)(2500 106 )(2 103 )
28.
a.
P=
(60 V)(15 A)
cos 30 = 389.7 W, Fp = 0.866
2
b.
P=
(50 V)(2 A)
cos 0 = 50 W, Fp = 1.0
2
c.
P=
(50 V)(3 A)
cos 10 = 73.86 W, Fp = 0.985
2
d.
P=
(75 V)(0.08 A)
cos 40 = 2.30 W, Fp = 0.766
2
2
29.
168
8A
V m 48 V
= 6 , P = I2R =
=
6 = 192 W
Im 8A
2
V I
(48 V)(8 A)
P = m m cos =
cos 0 = 192 W
2
2
48 V 8 A
P = VI cos θ =
cos 0 = 192 W
2 2
All the same!
R=
CHAPTER 14
30.
P = 100 W: Fp = cos θ = P/VI = 100 W/(150 V)(2 A) = 0.333
P = 0 W: Fp = cos θ = 0
300
=1
P = 300 W: Fp =
300
31.
P = V m I m cos
2
(50 V) I m
(0.5) Im = 40 A
500 W =
2
i = 40 sin(ωt 50)
32.
a.
Im = Em/R = 34 V/6.8 = 3.53 A, i = 3.53 sin(2π60t + 20)
b.
P = I 2R =
c.
T =
a.
Im =
b.
L=
c.
L0W
a.
Em = ImXC = (30 103 A)(2.4 k) = 72 V
e = 72 sin(2π500t 20 90) = 72 sin(2π500t 110)
b.
C=
c.
P=0W
33.
34.
35.
a.
2
3.53 A
2
2
6.8 Ω = 42.38 W
6.28
= 16.67 ms
ω 2 60 rad/s
6(16.67 ms) = 100.02 ms 0.1 s
=
Vm 128 V
= 4.27 A, i = 4.27 sin(1000t 30)
=
X L 30
XL
ω
=
30
= 30 mH, standard = 30 mH
1000 rad/s
1
1
= 0.133 μF standatd = 0.13 μF
=
3
ωX C (3.14 10 rad/s)(2.4 k)
1
1
1
= 50
=
=
4
2 f C1 ωC1 (10 rad/s)(2 F)
1
1
= 10
X C2 =
=
4
ωC 2 (10 )(10 F )
84.85 V 60
E
= 1.697 A 150
=
E = 84.85 V 60
I1 =
50 90
Z C1
X C1 =
I2 =
E
ZC 2
=
84.85 V 60
= 8.485 A 150
10 90
4
i1 = 2.4 sin(10 t + 150)
i2 = 12 sin(104t + 150)
CHAPTER 14
169
b.
CT 2 F 10 F 12 F
1
1
XC
4
C (10 rad/s)(12 F)
8.33
E
84.8560
Is =
XCT 8.33 90
= 10.19 A150
is = 14.4 sin (104t + 150°)
36.
a.
L1 L2 = 60 mH 120 mH = 40 mH
3
X LT = 2πfLT = 2π(10 Hz)(40 mH) = 251.33
Vm = I m X LT = 24 A (251.33 ) = 6.03 kV
and υs = 6.03 kV sin(103t + 30 + 90)
or υs = 6.03 103 sin(103t + 120)
b.
I m1 =
Vm
, X L1 = 2fL1 = 2(103 Hz)(60 mH) = 376.99
X L1
I m1 =
6.03 103 V
= 16 A
376.99
and i1 = 16 sin(103t + 30)
3
X L2 = 2πfL2 = 2π(10 Hz)(120 mH) = 753.98 Ω
I m2 =
6.03 103 V
=8A
753.98
and i2 = 8 A sin(103t + 30)
37.
a.
c.
e.
5.0 36.87
12.65 7.57
4123.11 104.04
b.
d.
f.
2.83 45
1001.25 2.86
0.894 116.57
38.
a.
c.
e.
17.89 116.57
20.22 × 103 8.53
200 0°
b.
d.
f.
8.94 26.57
8.49 × 103 135
1000 178.85
39.
a.
c.
e.
4.6 + j3.86
j2000
47.97 + j1.68
b.
d.
f.
6.0 + j10.39
6 × 103 j2.2 × 103
4.7 × 104 j1.71 × 104
40.
a.
c.
e.
42 + j0.11
3 × 103 j5.20 × 103
15
b.
d.
f.
1 × 103 j1.73 × 103
6.13 × 103 + j5.14 × 103
2.09 × 103 j1.20
170
CHAPTER 14
41.
42.
43.
44.
45.
46.
47.
48.
a.
11.8 + j7.0
b.
151.90 + j49.90
c.
4.72 × 106 + j71
a.
5.20 + j1.60
b.
209.30 + j311.0
c.
21.20 + j12.0
a.
12.17 54.70°
b.
98.37 13.38°
c.
28.07 115.91°
a.
12.0 + j34.0
b.
86.80 + j312.40
c.
283.90 j637.65
a.
8.00 20°
b.
49.68 64.0°
c.
40 × 10340°
a.
6.0 50°
b.
200 × 106 60°
c.
109 170°
a.
4
b.
4.15 j4.23
c.
6.69 j6.46
a.
10 j 5
= 10.0 j5.0
1 j0
b.
8 60
8 60
= 19.38 103 15.69
102 j 400 412.80 75.69
c.
(6 20)(120 40)(8.54 69.44) 6.15 103 49.44
= 3.07 103 79.44
2 30
2 30
CHAPTER 14
171
49
a.
(0.16 120)(300 40)
48 160
= 5.06 88.44
9.487 71.565
9.487 71.565
b.
1
1
8
2
4
4 10 20 j ( j ) 36 j 30
8
1
46.861
39.81
j
2500 20
(2500 20)(8j)(0.0213 39.81) = 426 109.81
50.
51.
a.
x + j4 + 3x + jy j7 = 16
(x + 3x) + j(4 + y 7) = 16 + j0
x + 3x = 16
4+y7=0
4x = 16
y = +7 4
x=4
y=3
b.
(10 20)(x 60) = 30.64 j25.72
10x 40 = 40 40
10 x = 40
x=4
5x + j10
2 jy
──────
10x + j20 j5xy j210y = 90 j70
(10x + 10y) + j(20 5xy) = 90 j70
10x + 10y = 90
x+y=9
x=9y
a.
20 5xy = 70
20 5(9 y)y = 70
5y(9 y) = 90
y2 9y + 18 = 0
(9) (9) 2 4(1)(18)
2
93
y=
= 6, 3
2
y=
For y = 6, x = 3
y = 3, x = 6
(x = 3, y = 6) or (x = 6, y = 3)
b.
52.
172
80 0
= 4 θ = 3.464 j2 = 4 30
40
θ = 30
a.
160.0 30
b.
25 103 40
c.
70.71 90
CHAPTER 14
53.
54.
55.
56.
a.
14.14 180
b.
4.24 106 90
c.
2.55 × 10670
a.
56.57 sin(377t + 20)
b.
169.68 sin (377t + 10)
c.
11.31 103 sin(377t 110)
d.
6000 sin(377t 180)
(Using peak values)
ein = υa + υb υa = ein υb
= 60 V 45 20 V 45
= 63.25 V 63.43
and ein = 63.25 sin (377t + 63.43)
is = i1 + i2 i1 = is i2
(Using peak values) = (20 106 A 60) (6 106 A 30) = 20.88 106 A 76.70
i1 = 20.88 106 sin (t + 76.70)
57.
ein = υa + υb + υc
υa = ein υb υc
= 120 V 30° 30 V 60° 40 V 120°
= 108.92 V 0.33°
ein = 108.92 sin(377t 0.33°)
58.
Is = I1 + I2 + I3
I1 = Is I2 I3
= 12.73 A 180° 5.66 A 180° 2[5.66 A 180°]
= 12.73 A 180° 5.66 A 180° 11.32 A 180°
= 4.25 A 0°
i1 = 6.01 sin 377t
CHAPTER 14
173
Chapter 15
1.
2.
a.
R 0 = 6.8 0 = 6.8
b.
XL = L = (377 rads/s)(1.2 H) = 452.4
XL 90 = 452.4 90 = +j452.4
c.
XL = 2fL = (6.28)(50 Hz)(47 mH) = 1.48
XL 90 = 1.48 90 = +j1.48
d.
XC =
e.
XC =
f.
R 0 = 220 0 = 220
a.
V = 10.61 V 10, I =
1
1
C (100 rad/s)(10 106 F)
XC 90 = 1 k 90 = j1 k
1
1
= 33.86
3
2 fC 2 (10 10 Hz)(0.47 F)
XC 90 = 33.86 90 = j33.86
V 10.61 V 10
= 3.54 A 10
R0
3 0
i = 5 sin (t + 10)
b.
= 1 k
V = 4.24 V 10, I =
V
4.24 V 10
= 4.24 A 80
X L 90
1 90
i = 6 sin (t 80)
c.
3.
1
1
= 15.924
2 fC 2 (5 kHz)(2 F)
84.84 V 0
V
= 5.328 A 90
I=
X C 90 15.924 90
i = 7.534 sin (t + 90)
V = 84.84 V 0, XC =
a.
I = (0.707)(4 mA 0) = 2.828 mA 0
V = (I 0)(R 0) = 2.828 mA 0)(22 0) = 62.216 mV 0
= 88 103 sin 1000t
b.
I = (0.707)(1.5 A 60) = 1.061 A 60
XL = 2πfL = 2π(200 Hz)(12 mH) = 15.08 Ω
V = (I )(XL 90) = (1.061 A 60)(15.08 90) = 16 V 150
= 22.62 sin(2π200t + 150)
174
CHAPTER 15
c.
I = (0.707)(2 mA 40) = 1.414 mA 40
1
1
= 135.52 k
XC =
C (157rad/s)(0.047 F)
V = (I )(XC 90) = (1.414 mA 40)(135.52 k 90) = 191.63 V 50
Vp = 2(191.63 V) = 270.96 V
and = 270.96 sin (157t 50)
4.
5.
6.
7.
a.
ZT = 6.8 + j8.2 = 10.65 50.33
b.
ZT = 2 j6 + 10 = 12 j6 = 13.42 26.57
c.
ZT = 1 k + j3.2 k + 5.6 k + j6.8 k = 6.6 k + j10 k = 11.98 k 56.58
a.
ZT = 3 + j4 j5 = 3 j1 = 3.16 18.43
b.
ZT = 1 k + j8 k j4 k = 1 k + j4 k = 4.12 k 75.96
c.
LT = 247 mH
XL = L = 2fL = 2(103 Hz)(247 103 H) = 1.55 k
1
1
XC =
= 1.59 k
3
2 fC 2 (10 Hz)(0.1 106 F)
= 470 + j1.55 k j1.59 k
= 470 j40 = 471.70 4.86
E 120 V 0
= 2 70 = 0.684 j1.879 = R jXC
I 60 A 70
a.
ZT =
b.
ZT =
c.
ZT =
a.
ZT = 8 + j6 = 10 36.87
c.
I = E/ZT = 100 V 0/10 36.87 = 10 A 36.87
VR = (I )(R 0) = (10 A 36.87)(8 0) = 80 V 36.87
VL = (I )(XL 90) = (10 A 36.87)(6 90) = 60 V 53.13
f.
P = I2R = (10 A)2 8 = 800 W
g.
Fp = cos θT = R/ZT = 8 /10 = 0.8 lagging
h.
R = 113.12 sin(t 36.87)
L = 84.84 sin(t + 53.13)
i = 14.14 sin (t 36.87)
CHAPTER 15
E 80 V 320
= 4 k 280 = 4 k 80 = 0.695 k j3.939
I 20 mA 40
= R jXC
8 kV 0
E
= 40 k 60 = 20 k + j34.64 k = R + jXL
I 0.2 A 60
175
8.
a.
ZT = 18 j29.15 = 34.26 58.30
1
1
= 29.15 Ω
XC =
2 fC 2 (60 Hz)(91 F)
c.
I=
120 V 20
E
= 3.50 A 78.30
=
ZT 34.26 58.30
VR = (I θ)(R 0) = (3.50 A 78.30)(18 0) = 63.0 V 78.30
VC = (I θ)(XC 90) = (3.50 A 78.30)(29.15 90) = 102.03 V 11.70
9.
f.
P = I2R = (3.50 A)2 18 = 220.5 W
g.
Fp = R/ZT = 18 /34.26 Ω = 0.525 leading
h.
i = 4.95 sin(377t + 78.30)
υR = 89.1 sin(377t + 78.30)
υC = 144.27 sin(377t 11.70)
a.
ZT = 4 + j6 j10 = 4 j4 = 5.66 45
c.
XL = ωL L =
d.
176
6
= 16 mH
377 rad/s
1
1
1
= 265 μF
C=
XC =
=
C
X C (377 rad/s)(10 )
XL
=
E
50 V 0
= 8.83 A 45
=
ZT
5.66 45
VR = (I θ)(R 0) = (8.83 A 45)(4 0) = 35.32 V 45
VL = (I θ)(XL 90) = (8.83 A 45)(6 90) = 52.98 V 135
VC = (I θ)(XC 90) = (8.83 A 45)(10 90) = 88.30 V 45
I=
f.
E = VR + VL + VC
50 V 0 = 35.32 V 45 + 52.98 V 135 + 88.30 V 45
50 V 0 = 49.95 V 0 50 V 0
g.
P = I2R = (8.83 A)2 4 = 311.88 W
h.
Fp = cos θT =
i.
i = 12.49 sin(377t + 45)
e = 70.7 sin 377t
υR = 49.94 sin(377t + 45)
υL = 74.91 sin(377t + 135)
υC = 124.86 sin(377t 45)
R
ZT
= 4 Ω/5.66 Ω = 0.707 leading
CHAPTER 15
10.
11.
a.
XL = ωL = (20 × 103 rad/s)(0.1H) = 2 kΩ
1
1
= 6.1 kΩ
XC =
3
C (20 10 rad/s)(8200 pF)
ZT = 1.2 kΩ + j2 kΩ j6.1 kΩ
= 1.2 kΩ j4.1 kΩ = 4.27 kΩ 73.69°
b.
c.
d.
I=
e.
f.
E = VR + VL + VC
4.24 V 60° = 1.19 V 133.69° + 1.99 V 223.69° + 6.06 V 43.69°
= (0.822 V + j0.80 V) + (1.44 V j1.37 V) + (4.38 V + j 4.19 V)
= 2.12 V+ j3.62 V
4.24 V 60° 4.20 V 59.65°
E
4.24 V60
= 0.993 mA 133.69°
ZT 4.27 k 73.69
VR = IR = (0.993 mA 133.69°)(1.2 kΩ 0°) = 1.19 V 133.69°
VL = IXL = (0.993 mA 133.69°)(2 kΩ 90°) = 1.99 V 223.69°
VC = IXC = (0.993 mA 133.69°)(6.1 kΩ 90°) = 6.06 V 43.69°
g.
P = I2R = (0.993 mA)2(1.2 kΩ) = 1.18 mW
h.
Fp =
i.
i = 1.4 × 103 sin (20,000t + 133.69°)
υR = 1.68 sin (20,000t + 133.69°)
υL = 2.81 sin (20,000t + 223.69°)
υC = 8.57 sin (20,000t + 43.69°)
R
1.2 k
= 0.281 leading
ZT 4.27 k
20 V (rms) 28.28 V (peak)
43.20 V(p p) 21.60 V (peak)
22 (28.28 V)
22 R
475.20 + 21.60R = 622.16
146.96
= 6.8 Ω
R=
21.60
Vscope = 21.60 V =
CHAPTER 15
177
12.
a.
22.8 V
= 8.06 V
VL (rms) = 0.7071
2
V (rms) 8.06 V
XL = L
= 6.2 kΩ
I (rms) 1.3 mA
XL = L = (1000rad/s)L = 6.2 kΩ L =
b.
6.2 k
= 6.2 H
1000 rad/s
E 2 VR2 VL2
(22 V)2 = VR2 (8.06 V) 2
484 VR2 64.96
VR2 419.04
VR 419.04 20.47 V
R
c.
13.
a.
VR (rms) 20.47 V
15.75 k
1.3 mA
I (rms)
6.2 H
8.27 V
= 2.924 V
VR(rms) = 0.7071
2
V (rms) 2.924 V
= 292.4 μA
I(rms) = R
10 k
R2
E 2 VR2 VC2
b.
(12 V) 2 (2.924 V) 2 VC2
144 8.55 VC2
VC2 135.35
VC 135.45 11.64 V
VC (rms) 11.64 V
= 39.81 kΩ
I (rms) 292.4 A
1
1
1
= 100 pF
XC =
C
2 fC
2 fX C 2 (40 kHz)(39.81 k)
XC =
14.
a.
b.
178
(2 k 0)(120 V 60) 240 V 60
= 29.09 V 15.96
=
2 k + j8 k
8.25 75.96
(8 k 90)(120 V 60)
= 116.36 V 74.04
V2 =
8.25 k 75.96
V1 =
( 40 90)(60 V 5) 2400 V 95
= 48.69 V 40.75
=
6.8 + j 40 + 22
28.8 + j 40
(22 0)(60 V 5)
1.32 kV 5
= 26.78 V 49.25
V2 =
=
49.29 54.25
49.29 54.25
V1 =
CHAPTER 15
15.
a.
b.
16.
17.
a.
(20 90)(20 V 70)
= 14.14 V 155
20 + j 20 j 40
(40 90)(20 V 70)
= 28.29 V 25
V2 =
28.28 45
V1 =
ZT = 4.7 k + j30 k + 3.3 k j10 k = 8 k + j20 k = 21.541 k 68.199
ZT = 3.3 k + j30 k j10 k = 3.3 k + j20 k = 20.27 k 80.631
Z E (20.27 k 80.631)(120 V 0)
= 112.92 V 12.432
V1 = T =
ZT
21.541 k 68.199
Z E
ZT = 3.3 k j10 k = 10.53 k 71.737
V2 = T
ZT
(10.53 k 71.737)(120 V 0)
= 58.66 V 139.94
=
21.541 k 68.199
XL = ωL = (1000 rad/s)(20 mH) = 20
1
1
=
= 25.64
XC =
ωC (1000 rad/s)(39 F)
ZT = 30 + j20 j25.64 = 30 j5.64 = 30.53 10.65
E
20 V 40
I=
= 655.1 mA 50.65
=
ZT 30.53 10.65
VR = (I θ)(R 0) = (655.1 mA 50.65)(30 0) = 19.65 V 50.65
VC = (655.1 mA 50.65)(25.64 90) = 16.80 V 39.35
R
30
= 0.983 leading
=
ZT 30.53
b.
cos θT =
c.
P = I2R = (655.1 mA)2 30 = 12.87 W
f.
VR =
g.
ZT = 30 j5.64 = R jXC
(30 0)(20 V 40)
600 V 40
= 19.66 V 50.65
=
ZT
30.53 10.65
(25.64 90)(20 V 40)
= 16.80 V 39.35
VC =
30.53 10.65
P = VI cos θ 8000 W = (200 V)(I)(0.8)
8000 A
= 50 A
I=
160
0.8 = cos θ
θ = 36.87
V = 200 V 0, I = 50 A 36.87
V
200 V 0
= 4 36.87 = 3.2 + j2.4
=
ZT =
I 50 A 36.87
CHAPTER 15
179
18.
P = VI cos 300 W = (120 V)(3 A) cos θ
cos θ = 0.833 θ = 33.59
V = 120 V 0, I = 3 A 33.59
V
120 V 0
= 40 33.59 = 33.34 + j22.10
=
ZT =
I 3 A 33.59
RT = 33.34 = 2 + R R = 31.34
19.
a.
b.
ZT =
R 2 + X L2 tan1XL/R
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
ZT
1.0 k
1.008 k
1.181 k
1.606 k
2.134 k
2.705 k
XLE
ZT
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
VL
0.0 V
0.623 V
2.66 V
3.888 V
4.416 V
4.646 V
VL =
c.
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
180
θT
0.0
7.16
32.14
51.49
62.05
68.3
θL = 90 tan1 XL/R
90.0
82.84
57.85
38.5
27.96
21.7
CHAPTER 15
d.
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
20.
a.
ZT =
│ZT│ =
1
2
2
R X C tan XC/R
R 2 X C2 , θT = tan1XC/R
f
0 kHz
1 kHz
3 kHz
5 kHz
7 kHz
10 kHz
CHAPTER 15
VR = RE/ZT
5.0 V
4.96 V
4.23 V
3.11 V
2.34 V
1.848 V
│ZT│
353.1
150.80
120.78
111.09
105.58
θT
90.0
73.55
48.46°
34.11
25.82
18.71
181
b.
VC =
XC E
( X C 90)(E 0)
90 + tan1XC/R
=
2
2
R jX C
R XC
│VC│ =
XC E
R 2 X C2
│VC│
10.0 V
9.59 V
7.49 V
5.61 V
4.36 V
3.21 V
f
0 Hz
1 kHz
3 kHz
5 kHz
7 kHz
10 kHz
c.
θC = 90 + tan1 XC/R
θC
0.0
16.45
41.54
55.89
64.18
71.29
f
0 Hz
1 kHz
3 kHz
5 kHz
7 kHz
10 kHz
d.
│VR│ =
RE
R X C2
f
0 Hz
1 kHz
3 kHz
5 kHz
7 kHz
10 kHz
182
2
│VR│
0.0 V
2.83 V
6.63 V
8.28 V
9.00 V
9.47 V
CHAPTER 15
21.
a.
R 2 ( X L X C ) 2 tan 1 ( X L X C ) / R
ZT =
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
b.
ZT
19.31 × 103
3.40 × 103
1.21 × 103
1.16 × 103
1.84 × 103
│VC│ =
XC E
ZT
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
c.
CHAPTER 15
θT
90.0
87.03
72.91
34.33
+30.75
+56.99
E
ZT
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
│VC│
120 V
120.62 V
136.94 V
192.4 V
133.45 V
63.29 V
I =
I
0.0 mA
6.21 mA
35.29 mA
99.17 mA
103.45 mA
65.22 mA
183
22.
1
1
1
= 1.54 kHz
=Rf=
2 fC
2 RC 2 (220 )(0.47 F)
a.
XC =
b.
Low frequency: XC very large resulting in large ZT
High frequency: XC approaches zero ohms and ZT approaches R
c.
f = 100 Hz: XC =
1
1
= 3.39 k
2 fC 2 (100 Hz)(0.47 F)
ZT XC
f = 10 kHz: XC =
1
1
= 33.86
2 fC 2 (10 kHz)(0.47 F)
ZT R
d.
e.
23.
a.
b.
24
184
1
1
= 8.47 k
2 fC 2 (40 kHz)(0.47 F)
X
8.47
= 2.2
= tan1 C tan 1
R
220
f = 40 kHz: XC =
1
1
0
0 = 0.147 S 0°
R
6.8
1
1
YT =
90 = 5 mS 90°
X L 90 200
YT =
1
1
1
90 = 0.5 mS 90°
ZT X C 90 2 k
c.
YT =
a.
ZT =
b.
22 2.2 = 2
(2 0)(6 90)
12 90
= 1.90 18.43
ZT =
2 j6
6.32 71.57
1
1
= 0.53 S 18.43° = 0.5 S + j0.17 S = G + jBC
YT =
ZT 1.90 18.43
c.
YT =
(10 0)(60 90)
= 9.86 9.46
10 j 60
1
1
YT =
= 0.10 S 9.46° = 0.1 S 0.02 S = G jBL
ZT 9.86 9.46
1
1
1
+
+
3 k 0 6 k 90 9 k 90
= 0.333 103 0 + 0.167 103 90 + 0.111 103 90
= 0.333 103 S j0.056 103 S = 0.34 mS 9.55
= G jBL
CHAPTER 15
25.
a.
ZT = 4.7 + j8 = 9.28 59.57, YT = 0.108 S 59.57
YT = 54.7 mS j93.12 mS = G jBL
b.
ZT = 33 + 20 j70 = 53 j70 = 87.80 52.87
YT = 11.39 mS 52.87 = 6.88 mS + j9.08 mS = G + jBC
c.
ZT = 200 + j500 j600 = 200 j100 = 223.61 26.57
YT = 4.47 mS 26.57 = 4 mS + j2 mS = G + jBC
26.
a.
YT =
b.
YT =
I 60 A 70
= 0.5 S 70 = 0.171 S + j0.470 S = G + jBC
=
E 120 V 0
1
1
= 5.85 , XC =
= 2.13
R=
G
BC
I 20 mA 40
= 0.25 mS 280 = 0.25 mS 80
=
E 80 V 320
= 0.043 mS + j0.246 mS = G + jBC
1
1
R=
= 23.26 k, XC =
= 4.07 k
G
BC
27.
I 0.2 A 60
= 0.25 mS 60 = 0.0125 mS j0.02165 mS = G jBL
=
E
8 kV 0
1
1
R=
= 80 k, XL =
= 46.19 k
G
BL
c.
YT =
a.
YT =
c.
E = Is/YT = 2 A 0/111.8 mS 26.57= 17.89 V 26.57
E
= 17.89 V 26.57/10 0 = 1.79 A 26.57
IR =
R 0
E
IL =
= 17.89 V 26.57/20 90 = 0.89 A 63.43
X L 90
f.
P = I2R = (1.79 A)2 10 = 32.04 W
g.
Fp =
h.
e = 25.30 sin(377t + 26.57)
iR = 2.53 sin(377t + 26.57)
iL = 1.26 sin(377t 63.43)
is = 2.83 sin 377t
CHAPTER 15
1
1
= 0.1 S j0.05 S = 111.8 mS 26.57
+
10 0 20 90
G
YT
=
0.1 S
= 0.894 lagging
111.8 mS
185
28.
a.
XC =
b.
YT =
c.
29.
1
1
= 20.4 kΩ
2 fC 2 (60 Hz)(0.13 F)
1
1
+
= 0.1 mS 0 + 0.049 mS 90
10 k 0 20.4 k 90
= 0.111 mS 26.10
2 mA 20
Is
= 18.02 V 6.1
=
0.111 mS 26.10
YT
E
18.02 V 6.1
=
= 1.80 mA 6.1
IR =
10 k 0
ZR
18.02 V 6.1
E
IC =
=
= 0.883 mA 83.90
20.4 k 90
ZC
E=
e.
Is = IR + IC
2 mA 20 = 1.80 mA 6.1 + 0.883 mA 83.90
= (1.79 mA j0.191 mA) + (0.094 mA + j0.878 mA)
= 1.88 mA + j0.687 mA
2 mA 20° 2 mA 20.07°
f.
P = I2R = (1.80 mA)2 10 k = 32.4 mW
g.
Fp =
h.
ω = 2f = 377 rad/s
a.
c.
G
YT
=
0.1 mS
= 0.9 leading
0.111 mS
is = 2.83 103 sin(ωt + 20)
iR = 2.55 103 sin(ωt 6.57)
iC = 1.25 103 sin(ωt + 83.44)
e = 25.48 sin(ωt 6.57)
1
1
1
1.2 0 2 90 5 90
= 0.833 S 0 + 0.5 S 90 + 0.2 S 90
= 0.833 S j0.3 S = 0.89 S 19.81
ZT = 1.12 19.81
YT =
XC =
1
1
1
C=
= 531 μF
=
C
X C (377 rad/s)(5 )
XL = ωL L = X L =
ω
186
2
= 5.31 mH
377 rad/s
CHAPTER 15
d.
g.
Is = IR + IL + IC
2.121 A 60 = 2.00 A 79.81 + 1.20 A 10.19 + 0.48 A 169.81
2.121 A 60 = 2.13 A 60.01
2
P = I R = (2.00 A)2 1.2 = 4.8 W
h.
Fp =
i.
e = 3.39 sin(377t + 79.81)
iR = 2.83 sin(377t + 79.81)
iL = 1.70 sin(377t 10.19)
iC = 0.68 sin(377t + 169.81)
f.
30.
(0.707)(3 A) 60
2.121 A 60
=
E = Is =
= 2.40 V 79.81
0.885 S 19.81 0.885 S 19.81
YT
E 2.397 V 79.81
IR =
= 2.00 A 79.81
=
R 0
1.2 0
E
2.397 V 79.81
=
IL =
= 1.20 A 10.19
2 90
X L 90
2.397 V 79.81
E
IC =
=
= 0.48 A 169.81
5 90
X C 90
a.
G
YT
=
0.833 S
= 0.941 lagging
0.885 S
XL = L = (1000 rad/s)(3.9 H) = 3.9 kΩ,
1
1
= 8.33 kΩ
XC =
C (1000 rad/s)(0.12 F)
1
1
1
YT =
+
+
3 k 0 3.9 k 90 8.33 k 90
= 0.333 mS 0 + 0.256 mS 90 + 0.120 mS 90
= 0.333 mS j0.136 mS = 0.36 mS 22.22
d.
E = I/YT = 3.54 mA 20/0.36 mS 22.22 = 9.83 V 2.22
E
IR =
= 9.83 V2.22/3 k 0 = 3.28 mA 2.22
R 0
E
IL =
= 9.83 V2.22/3.9 k 90 = 2.52 mA 87.78
X L 90
E
= 9.83 V2.22/8.33 k 90 = 1.18 mA 92.22
IC =
X C 90
g.
P = I2R = (3.28 mA)23 k = 32.28 mW
h.
Fp = G/YT = 0.333 mS/0.36 mS = 0.925 leading
i.
e = 13.9 sin(1000t + 2.22)
iR 4.64 103 sin(1000t + 2.22)
iL 3.56 103 sin(1000t 87.78)
iC = 1.67 103 sin(1000t + 92.22)
CHAPTER 15
187
31.
a.
b.
(60 90)(20 A 40) 1200 A 130
= 18.78 60.14°
22 j 60
63.91 69.86
(22 0)(20 A 40)
440 A 40
I2 =
= 6.88 29.86°
63.91 69.86
63.91 69.86
I1 =
(12 j 6 )(6 A 30) (13.42 26.57)(6 A 30)
12 j 6 j 4
12 j 2
80.52 A 3.43
= 6.62 A 12.89°
=
12.17 9.46
I1 =
I2 =
c.
32.
a.
(4 90)(6 A 30)
24 A 120
= 1.97 A 129.46°
12.17 9.46
12.17 9.46
( j10 j 40 )(4 A 0) (30 90)(4 A 0)
j 20 j10 j 40
50 90
= 2.4 A 0°
I1 =
I2 =
(20 90)(4A 0)
= 1.6 A 0°
50 90
ZT =
(R 0 )( X C 90 )
= RX C 90 + tan1XC/R
2
2
R jX C
R XC
│ZT│ =
f
0 Hz
1 kHz
2 kHz
3 kHz
4 kHz
5 kHz
10 kHz
20 kHz
188
RX C
R
2
X C2
│ZT│
40.0
35.74
28.22
22.11
17.82
14.79
7.81
3.959
θT = 90 + tan1XC/R
θT
0.0
26.67
45.14
56.44
63.55
68.30
78.75
89.86
CHAPTER 15
b.
IRX C
│VC│ =
R 2 + X C2
│VC│
2.0 V
1.787 V
1.411 V
1.105 V
0.891 V
0.740 V
0.391 V
0.198 V
f
0 kHz
1 kHz
2 kHz
3 kHz
4 kHz
5 kHz
10 kHz
20 kHz
c.
│IR│ =
VC
R
│IR│
50.0 mA
44.7 mA
35.3 mA
27.64 mA
22.28 mA
18.50 mA
9.78 mA
4.95 mA
f
0 kHz
1 kHz
2 kHz
3 kHz
4 kHz
5 kHz
10 kHz
20 kHz
33.
a.
( R 0)( X L 90)
ZR ZL
=
=
ZR ZL
R jX L
ZT =
│ZT│ =
f
0 Hz
1 kHz
5 kHz
7 kHz
10 kHz
CHAPTER 15
= I[ZT(f)]
RX L
R
2
X L2
RX L
R
2
X L2
90 tan1XL/R
θT = 90 tan1XL/R
| ZT |
0.0 k
1.22 k
3.91 k
4.35 k
4.65 k
θT
90.0
75.86
38.53
29.6
21.69
189
│IL│ =
b.
34.
f
| IL |
0 Hz
1 kHz
5 kHz
7 kHz
10 kHz
31.75 mA
6.37 mA
4.55 mA
3.18 mA
IR =
c.
YT =
E
XL
E 40 V
= 8 mA (constant)
=
R 5k
R 2 X C2
RX C
90 tan1XC/R
f
│YT│
0 Hz 25.0 mS
1 kHz 27.98 mS
2 kHz 35.44 mS
3 kHz 45.23 mS
4 kHz 56.12 mS
5 kHz 67.61 mS
10 kHz 128.04 mS
20 kHz 252.59 mS
35.
YT =
1
(use data of Prob. 36), TY = TZ
ZT
f
0 Hz
1 kHz
5 kHz
7 kHz
10 kHz
190
θT
0.0
26.67
45.14
56.44
63.55
68.30
78.75
89.86
YT
0.82 mS
0.256 mS
0.23 mS
0.215 mS
θT
90.0
75.86
38.53
29.6
21.69
CHAPTER 15
36.
a.
YT = G 0 + BL 90 + BC 90
B BL
= G 2 ( BC BL ) 2 tan1 C
G
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
f
0 Hz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
b.
ZT =
1
YT
f
0 kHz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
CHAPTER 15
│YT│
XL 0 , ZT = 0 ,
YT =
1.86 mS
1.02 mS
1.00 mS
1.02 mS
1.04 mS
│θT│
90.0
57.51
12.63
+1.66
+9.98
+16.54
, T Z = T Y
ZT
0.0
537.63
980.39
1 k
980.39
961.54
θT
90.0
57.52
12.63
1.66
9.98
16.54
191
c.
VC(f) = I[ZT(f)]
│VC│
0.0 V
5.38 V
9.80 V
10 V
9.80 V
9.62 V
f
0 kHz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
d.
IL =
VL (f) VC ( f )
XL
XL
f
0 kHz
1 kHz
5 kHz
10 kHz
15 kHz
20 kHz
37.
a.
b.
IL
10.0 mA
8.56 mA
3.12 mA
1.59 mA
1.04 mA
0.765 mA
Rp =
Rs2 X s2 (20 ) 2 (40 ) 2
= 100 (R)
20
Rs
Xp =
Rs2 X s2 2000
= 50 (C)
40
Xs
Rp =
Rs2 X s2 (2 k ) 2 + (8 k ) 2
= 34 k (R)
=
Rs
2 k
Rs2 X s2 (2 k ) 2 + (8 k ) 2
= 8.5 k (L)
Xp =
=
Xs
8k
38.
a.
R p X p2
(8.2 k )(20 k ) 2
= 7.02 k
=
Rs = 2
X p R p2 (20 k ) 2 + (8.2 k ) 2
Xs =
R p2 X p
X p2 R p2
=
(8.2 k ) 2(20 k )
= 2.88 k
467.24 k
ZT = 7.02 k j2.88 k
b.
Rs =
Xs =
R p X p2
X p2 R p2
R p2 X p
X p2 R p2
=
(68 )(40 ) 2
= 17.48
(40 ) 2 + (68 ) 2
=
(68 ) 2(40 )
= 29.72
6224 2
ZT = 17.48 + j29.72
192
CHAPTER 15
39.
a.
CT = 2 μF
1
1
= 79.62
XC =
=
3
C 2 (10 Hz)(2 F)
XL = ωL = 2π(103 Hz)(10 mH) = 62.80
YT =
1
1
1
220 0 79.62 90 62.8 90
= 4.55 mS 0 + 12.56 mS 90 + 15.92 mS 90
= 4.55 mS j3.36 mS = 5.66 mS 36.44
E = I/YT = 1 A 0/5.66 mS 36.44 = 176.68 V 36.44
E
= 176.68 V 36.44/220 0 = 0.803 A 36.44
IR =
R 0
E
= 176.68 V 36.44/62.80 90 = 2.813 A 53.56
IL =
X L 90
40.
b.
Fp = G/YT = 4.55 mS/5.66 mS = 0.804 lagging
c.
P = I2R = (0.803 A)2 220 = 141.86 W
f.
Is = IR + 2IC + IL
I I IL
and IC = s R
2
1 A 0 0.803 A 36.44 2.813 A 53.56
=
2
1 (0.646 j 0.477) (1.671 j 2.263) 1.317 j1.786
=
2
2
IC = 0.657 + j0.893 = 1.11 A 126.43
g.
ZT =
1
1
= 176.7 36.44
=
YT
5.66 mS 36.44
= 142.15 + j104.96 = R + jXL
P = VI cos θ = 3000 W
3000 W
3000 W
3000
= 0.75 (lagging)
=
=
cos θ =
VI
(100 V)(40 A) 4000
θ = cos1 0.75 = 41.41
I
40 A 41.41
= 0.4 S 41.41 = 0.3 S j0.265 S = GT jBL
=
YT =
E
100 V 0
1
1
1
GT = 0.3 S =
+ = 0.05 S +
20 R
R
1
and R =
=4
0.25 S
CHAPTER 15
193
XL =
41.
1
BL
1
= 3.74
0.265 S
a.
b.
c.
42.
194
a.
e and R2
b.
e and is
CHAPTER 15
43.
c.
iL and iC
(I):
(a)
θdiv. = 0.8 div., θT = 4 div.
0.8 div.
360 = 72
θ=
4 div.
1 leads 2 by 72
(b)
1: peak-to-peak = (5 div.)(0.5 V/div.) = 2.5 V
2.5 V
V1(rms) = 0.7071
= 0.88 V
2
2: peak-to-peak = (2.4 div.)(0.5 V/div.) = 1.2 V
1.2 V
V2(rms) = 0.7071
= 0.42 V
2
(II):
(c)
T = (4 div.)(0.2 ms/div.) = 0.8 ms
1
1
=
= 1.25 kHz (both)
f=
T
0.8 ms
(a)
θdiv. = 2.2 div., θT = 6 div.
2.2 div.
θ=
360 = 132
6 div.
1 leads 2 by 132
(b)
1: peak-to-peak = (2.8 div.)(2 V/div.) = 5.6 V
5.6 V
V1(rms) = 0.7071
= 1.98 V
2
2: peak-to-peak = (4 div.)(2 V/div.) = 8 V
8V
V2(rms) = 0.7071
= 2.83 V
2
(c)
CHAPTER 15
T = (6 div.)(10 s/div.) = 60 μs
1
1
=
= 16.67 kHz
f=
T
60 s
195
Chapter 16
1.
2.
ZT = j4 +
b.
Is =
c.
I1 = 3.5 A 22.65
d.
I2 =
e.
VL = Is XL = (3.5 A 22.65)(4 90) = 14 V 112.65
a.
ZT = 3 + j6 + 2 0 8 90
= 3 + j6 + 1.94 14.04
= 3 + j6 + 1.88 j0.47
= 4.88 + j5.53 = 7.38 48.57
b.
Is =
c.
IC =
=
d.
3.
196
(8 90)(12 0)
= 3.69 j1.54 4 22.65
j8 12
a.
a.
14 V 0
E
= 3.5 A 22.65
=
4 22.65
ZT
(8 90)(3.5 A 22.65)
= 1.94 A 33.66
12 j8
30 V 0
E
= 4.07 A 48.57
=
ZT 7.38 48.57
Z R2 I s
Z R2 + Z C
=
(2 0)(4.07 A 48.57)
2 j8
8.14 A 48.57
= 0.987 A 27.39
8.25 75.96
Z L E (6 90)(30 V 0)
180 V 90
=
=
ZT
7.38 48.57
7.38 48.57
= 24.39 V 41.43
VL =
ZT = 12 90 (9.1 j12 Ω) = 12 90 15.06 52.826
180.72 37.17
=
9.100
= 19.86 37.17
E
60 V 0
= 3.02 A 37.17
19.86 37.17
b.
Is =
c.
(CDR) I2 =
ZT
=
(12 Ω 90°)(3.02 A 37.17) 36.24 A 52.83
=
j12 + 9.1 j12
9.1 0
= 3.98 A 52.83
CHAPTER 16
4.
5.
(12 90)(60 V 0)
720 V 90
=
9.1 j12
15.06 52.826
= 47.81 V 37.17
d.
(VDR) VC =
e.
P = EI cos θ = (60 V)(3.02 A)cos(37.17)
= 181.20(0.797) = 144.42 W
a.
6.8 k
0 8 k 90
(4 k 90)(6 k 90) 2
ZT = 2 k 0 +
6.8 k
j 4 k j 6 k
j 8 k
2
24 k 0
27.2 k 90
= 2 k +
2 90
3.4 k j8 k
8.69 k 66.97
= 2 k + j12 k 3.13
k
23.03
2.88 k j1.22 k
= 2 k + 7.88 kΩ j12 k + j1.22 k
ZT = 4.88 k j10.78 k = 11.83 k 65.64
b.
V2 = IZT' = (4 mA 0)(3.13 k 23.03) = 12.52 V 23.03
V
12.52 V 23.03)
= 1.57 A 66.97
IL = 2
X L2
8 k 90
c.
Fp =
a.
400 Ω 90 400 90 =
b.
VC =
c.
P = EI cos θ = (100 V)(0.25 A) cos 36.86
= (25)(0.8) = 20 W
4.88 k
R
= 0.413 (leading)
ZT 11.83 k
400 90
= 200 90
2
Z = 100 j200 = 223.61 63.43
Z = j200 + j600 = +j400 = 400 90
(223.61 63.43)(400 90) 89444.00 26.57
ZT = Z Z =
(100 j 200 ) j 400
223.61 63.43
= 400 36.86
100 V 0
E
= 0.25 A 36.86
I=
=
400 36.86
ZT
CHAPTER 16
(200 90)(100 V 0) 20, 000 V 90
= 89.44 V 26.57
=
100 j 200
223.61 63.43
197
6.
a.
Z1 = 3 + j4 = 5 53.13
E
120 V 0
I1 =
= 24 A 53.13
=
Z1 5 53.13
b.
VC =
c.
VR1 = (I1 θ)R 0 = (24 A 53.13)(3 0) = 72 V 53.13
(13 90)(120 V 0) 1560 V 90
= 260 V 0
=
j13 + j 7
6 90
Vab + VR1 VC = 0
+-
Vab = VC VR1 = 260 V 0 72 V 53.13
+-
= 260 V (43.20 V + j57.60 V)
= 216.80 V + j57.60 V = 224.32 V 14.88
7.
Z1 = 10 0
Z2 = 80 90 20 0
1600 90
1600 90
=
20 j80
82.462 75.964
= 19.403 14.036
Z3 = 60 90
a.
ZT = (Z1 + Z2) Z3
= (10 + 18.824 + j4.706 ) 60 90
1752.36 80.727
= 29.206 9.273 6 90 =
28.824 j 4.706 j 60
1752.36 80.727
=
= 28.103 18.259
62.356 62.468
E
40 V 0
= 1.42 A 18.26
I1 =
=
ZT 28.103 18.259
198
Z 2E
(19.403 14.036)(40 V 0) 776.12 V 14.036
=
=
29.206 9.273
29.206 9.273
Z 2 + Z1
= 26.57 V 4.76
b.
V1 =
c.
P = EI cos θ = (40 V)(1.423 A)cos 18.259
= 54.07 W
CHAPTER 16
8.
a.
Z1 = 2 + j1 = 2.236 26.565, Z2 = 3 0
Z3 = 16 + j15 j7 = 16 + j8 = 17.889 26.565
1
1
1
1
1
1
YT =
+
+
=
+
+
Z1 Z 2 Z 3 2.236 26.565 3 0 17.889 26.565
= 0.447 S 26.565 + 0.333 S 0 + 0.056 S 26.565
= (0.4 S j0.2 S) + (0.333 S) + (0.05 S j0.025 S)
= 0.783 S j0.225 S = 0.82 S 16.03
1
1
= 1.23 16.03
ZT =
=
YT
0.82 S 16.03
b
I1 =
E
60 V 0
= 26.83 A 26.57
=
Z1 2.236 26.565
E 60 V 0
= 20 A 0
=
Z 2 3 0
60 V 0
E
I3 =
= 3.35 A 26.57
=
Z3 17.889 26.565
I2 =
c.
Is =
60 V 0
E
= 48.9 A 16.03
=
ZT 1.227 16.032
?
Is = I1 + I2 + I3
?
48.9 A 16.03 = 26.83 A 26.57 + 20 A 0 + 3.35 A 26.57
= (24 A j12 A) + (20 A) + (3 A j1.5 A)
= 47 A + j13.5 A = 48.9 A 16.03 (checks)
9.
d.
Fp =
a.
X L1
G 0.783 S
= 0.955 (lagging)
=
YT 0.820 S
= ωL1 = 2(103 Hz)(0.1 H) = 628
X L2 = ωL2 = 2(103 Hz)(0.2 H) = 1.256 k
1
1
= 0.159 k
=
3
C 2 (10 Hz)(1 F)
ZT = R 0 + X L1 90 + XC 90 X L2 90
XC =
= 300 + j628 + 0.159 k 90 1.256 k 90
= 300 + j628 j182
= 300 + j446 = 537.51 56.07
b.
Is =
CHAPTER 16
E
50 V 0
= 93 mA 56.07
=
ZT 537.51 56.07
199
c.
(CDR):
I1 =
Z L2 I s
Z L2 + ZC
=
(1.256 k 90)(93 mA 56.07)
+ j1.256 k j 0.159 k
116.81 mA 33.93
= 106.48 mA 56.07
1.097 90
ZC I s
(0.159 k 90)(93 mA 56.07)
I2 =
=
Z L2 + Z C
1.097 k 90
=
14.79 mA 146.07
= 13.48 mA 236.07
1.097 90
= 13.48 mA 123.93
=
d.
V1 = (I2 θ)( X L2 90) = (13.48 mA 123.92)(1.256 k 90)
= 16.93 V 213.93
Vab = E (Is θ)(R 0) = 50 V 0 (93 mA 56.07)(300 0)
+-
= 50 V 27.9 V 56.07
= 50 V (15.573 V j23.149 V)
= 34.43 V + j23.149 V = 41.49 V 33.92
10.
e.
P = I s2 R = (93 mA)2300 = 2.595 W
f.
Fp =
a.
ZT = 1.2 k +
R
300 Ω
= 0.558 (lagging)
=
ZT 537.51 Ω
= 1.2 k +
(1.2 k 0)(1.8 k 90) 2.4 k 90
1.2 k j1.8 k
2
2.16 k 90
1.2 k 90
2.16 56.31
= 1.2 k + 1 k 33.69 + j1.2 k
= 1.2 k + 832.05 j554.70 + j1.2 k
= 2.03 k + j645.30 = 2.13 k 17.63
200
b.
V1 = IR1 = (20 mA 0)(1.2 k 0) = 24 V0
c.
I1 =
d.
(2.4 k)
V2 = I(X L1 X L2 ) = (20 mA 0)
90 = 24 V 90
2
e.
Vs = IZT = (20 mA 0)(2.13 k 17.63) = 42.60 V 17.63
(1.2 k 0)(20 mA 0)
2.4 A 0
= 11.11 mA 56.31
1.2 k j1.8 k
2.16 103 56.31
CHAPTER 16
11.
Z1 = 2 j2 = 2.828 45
Z2 = 3 j9 + j6
= 3 j3 = 4.243 45
Z3 = 10 0
a.
1
1
1
1
1
1
+
+
=
+
+
Z1 Z 2 Z 3
2.828 45
4.243 45 10 0
= 0.354 S 45 + 0.236 S 45 + 0.1 S 0 = 0.59 S 45 + 0.1 S 0
= 0.417 S + j0.417 S + 0.1 S
YT = 0.517 S + j 0.417 S = 0.66 S 38.89
1
1
= 1.52 38.89
ZT =
=
YT
0.66 S 38.89
YT =
12.
b.
V1 =
c.
I1 =
d.
Is =
(2 0)(60 V0)
120 V 0
= 42.43 V 45
2 j
2.828 45
60 V 0
60 V 0
60 V 0
E
Z 3 j 9 j 6 3 j 3 4.243 45
= 14.14 A 45
60 V 0
E
= 39.47 A 38.89
ZT 1.52 38.89
Z = 12 j20 = 23.32 59.04
R4 0 Z = 20 0 23.32 59.04 = 12.36 27.03
Z = R3 0 + R4 0 Z = 12 + 12.36 27.03
= 12 + (11.01 j5.62 )
= 23.01 j5.62 = 23.69 13.73
R2 0 Z = 20 0 23.69 13.73 = 10.92 6.29
ZT = R1 0 + R2 0 Z = 12 + 10.92 6.29
= 12 + (10.85 j1.25 )
= 22.85 j1.2 = 22.88 3.01
E
100 V 0
Is =
= 4.37 A +3.01
=
ZT
22.88 3.01
I R1 = I
I R3 =
R2 0 I s
(20 0)(4.37 A 3.01) 87.40 A 3.01
=
=
43.38 7.44
R2 0 Z " 20 23.01 j 5.62
= 2.01 A 10.45
R4 0I R3
(20 0)(2.01 A 10.45) 40.20 A 10.45 40.20 A 10.45
=
20 + 12 j 20
32 j 20
37.74 32.01
R4 0 + Z
= 1.07 A 42.46
I4 =
CHAPTER 16
=
201
13.
R3 + R4 = 2.7 k + 4.3 k = 7 k
R = 3 k 7 k = 2.1 k
Z = 2.1 k j10
(CDR)
(CDR)
14.
(40 k 0)(20 mA 0)
40 k + 2.1 k j10
= 19 mA +0.014 as expected since R1 Z
I (of 10 cap.) =
(3 k 0)(19 mA 0.014) 57 mA 0.014
=
3k + 7 k
10
= 5.7 mA 0.014
P = I2R = (5.7 mA)2 4.3 k = 139.71 mW
I4 =
Z = X C2 90 R1 0 = 2 90 1 0
2 90
2 90
1 j2
2.236 63.435
= 0.894 26.565
Z = X L2 90 + Z = +j8 + 0.894 26.565
=
= +j8 + (0.8 j4 )
= 0.8 + j4 = 4.079 78.69
IXL =
2
X C1 90I
X C1 90 Z
(2 90)(0.5 A 0) 1 A 90
0.8 j 2
j 2 (0.8 j 4 )
1 A 90
= 0.464 A 158.99
2.154 68.199
X C2 90 I X C
(2 90)(0.464 A 158.99) 0.928 A 248.99
2
=
=
I1 =
X C2 90 + R1
j2 + 1
2.236 63.435
=
= 0.42 A 174.45
202
CHAPTER 16
Chapter 17
1.
2.
Z = −j5 + 2 0 5 90 = −j5 + 1.72 + j0.69 = 4.64 −68.24
E
60 V 30
= 12.93 A 98.24
I=
=
Z 4.64 68.24
3.
Z = 10 0 6 90 = 5.15 59.04
E = IZ = (2 A 120)(5.15 59.04)
= 10.30 V 179.04
4.
a.
I=
b.
V = (hI)(R) = (50 I)(50 kΩ) = 2.5 106 I
Z = 50 k 0
5.
V
16 V
= 4 103 V
R
4 103
Z = 4 k 0
=
Clockwise mesh currents:
E I1Z1 I1Z2 + I2Z2 = 0
I2Z2 + I1Z2 I2Z3 E2 = 0
────────────────────
[Z1 + Z2]I1 Z2I2 = E1
Z2I1 + [Z2 + Z3]I2 = E2
──────────────────
Z 2
E1
E2
Z 2 + Z3
I R1 = I1 =
Z1 + Z 2 Z 2
Z 2
6.
Z1 = R1 0 = 4 0
Z2 = XL 90 = 6 90
Z3 = XC 90 = 8 90
E1 = 10 V 0, E2 = 40 V 60
=
Z 2 + Z3 E1
Z 2 E2
Z1Z 2 + Z1Z3 + Z 2 Z 3
= 5.15 A 24.5
Z 2 + Z3
By interchanging the right two branches, the general configuration of Problem 5 will result and
I50Ω = I1 =
Z2
Z3 E1 Z 2 E 2
Z1Z 2 + Z1Z3 + Z 2 Z 3
= 0.44 A 143.48
CHAPTER 17
Z1 = R1 = 50 0
Z2 = XC 90 = 60 90
Z3 = XL 90 = 20 90
E1 = 5 V 30, E2 = 20 V 0
203
7.
a.
Z1 = 12 + j12 = 16.971 45
Z2 = 3 0
Z3 = j1
E1 = 20 V 50
E2 = 60 V 70
E3 = 40 V 0
I1[Z1 + Z2] Z2I2 = E1 E2
I2[Z2 + Z3] Z2I1 = E2 E3
───────────────────
(Z1 + Z2)I1 Z2I2 = E1 E2
Z2I1 + (Z2 + Z3)I2 = E2 E3
─────────────────────
Using determinants:
(E E2 )(Z 2 + Z 3 ) + Z 2 (E 2 E3 )
= 2.55 A 132.72
I R1 = I1 = 1
Z1Z 2 + Z1Z3 + Z 2 Z 3
8.
Clockwise mesh currents:
E1 I1Z1 I1Z2 + I2Z2 = 0
I2Z2 + I1Z2 I2Z3 I2Z4 + I3Z4 = 0
I3Z4 + I2Z4 I3Z5 E2 = 0
─────────────────────────
Z2 I 2
[Z1 + Z 2 ]I1
Z2
Z1 = 4 + j3 , Z2 = j1
Z3 = +j6 , Z4 = j2
Z5 = 8
E1 = 60 V 0, E2 = 120 V 120
+0
= E1
Z4 I3 = 0
I1 + [Z 2 + Z 3 + Z 4] I 2
Z 4 I 2 + [ Z 4 + Z 5]I 3 = E 2
0
───────────────────────────────────
I R1 = I 3 =
Z 2Z 4 E1 + Z 22 Z1 + Z 2 Z 2 + Z3 + Z 4 E2
Z1 + Z 2 Z 2 + Z3 + Z 4 Z 4 + Z5 Z1 + Z 2 Z 24 Z 4 + Z5 Z 22
= 13.07 A 33.71°
204
CHAPTER 17
9.
Z1 = 15 0, Z2 = 15 0
Z3 = j10 = 10 90
Z4 = 3 + j4 = 5 53.13
E1 = 220 V 0
E2 = 100 V 90
I1(Z1 + Z3) I2Z3 I3Z1 = E1
I2(Z2 + Z3) I1Z3 I3Z2 = E2
I3(Z1 + Z2 + Z4) I1Z1 I2Z2 = 0
───────────────────────
I3Z1
= E1
I1(Z1 + Z3) I2Z3
I1Z3
+ I2(Z2 + Z3) I3Z2
= E2
I1Z1
I2Z2
+ I3(Z1 + Z2 + Z4) = 0
───────────────────────────────────
Applying determinants:
I3 =
( Z1 + Z 3)( Z 2 )E 2 Z1Z 3E 2 + E1 Z 2 Z 3 + Z1( Z 2 + Z 3)
( Z1 + Z 3) ( Z 2 + Z 3)( Z1 + Z 2 + Z 4 ) Z 22 + Z 3 Z 3( Z1 + Z 2 + Z 4 ) Z1Z 2 Z1 Z 2 Z 3 Z1( Z 2 + Z 3)
= 48.33 A 77.57
or I3 = E1 E 2 if one carefully examines the network!
Z4
10.
Z1 = 5 0, Z2 = 5 90
Z3 = 4 0, Z4 = 6 90
Z5 = 4 0, Z6 = 6 + j8
E1 = 20 V 0, E2 = 40 V 60
I1(Z1 + Z2 + Z4) I2Z2 I3Z4 = E1
I2(Z2 + Z3 + Z5) I1Z2 I3Z5 = E2
I3(Z4 + Z5 + Z6) I1Z4 I2Z5 = 0
─────────────────────────
Z2I2
Z4I3 = E1
(Z1 + Z2 + Z4) I1
Z5I3 = E2
Z2I1 + (Z2 + Z3 + Z5)I2
Z5I2 + (Z4 + Z5 + Z6)I3 = 0
Z4I1
─────────────────────────────────────────
Using Z = Z1 + Z2 + Z4, Z = Z2 + Z3 + Z5, Z = Z4 + Z5 + Z6 and determinants:
E1 (Z Z Z 52 ) E 2 (Z 2 Z + Z 4 Z5 )
I R1 = I1 =
Z (Z Z Z52 ) Z 2 (Z 2 Z + Z 4 Z5 ) Z 4 (Z 2 Z5 + Z 4 Z )
= 3.04 A 169.12°
CHAPTER 17
205
11.
Z1 = 10 + j20
Z3 = 80 0
Z5 = 15 90
Z7 = 5 0
E1 = 25 V 0
Z2 = j20
Z4 = 6 0
Z6 = 10 0
Z8 = 5 Ω j20
E2 = 75 V 20
I1(Z4 + Z6 + Z7) I2Z4 I4Z6 = E1
I2(Z1 + Z2 + Z4) I1Z4 I3Z2 = 0
I3(Z2 + Z3 + Z5) I2Z2 I4Z5 = E2
I4(Z5 + Z6 + Z8) I1Z6 I3Z5 = 0
─────────────────────────
Z4 I2
+0
Z6I4 = E1
(Z4 + Z6 + Z7) I1
Z4I1 + (Z1 + Z2 + Z4)I2
Z2I3
+0 =0
Z5I4 = E2
0
Z2 I2 + (Z2 + Z3 + Z5)I3
+0
Z5I3 + (Z5 + Z6 + Z7)I4 = 0
Z6I1
────────────────────────────────────────────────────
Applying determinants:
I R1 = I 80 = 0.68 A 162.9
12.
Z1 = 5 k 0
Z2 = 10 k 0
Z3 = 1 k + j4 k = 4.123 k 75.96
I1(Z1 + Z2) Z2I2 = 28 V
I2(Z2 + Z3) Z2I1 = 0
──────────────────
(Z1 + Z2)I1 Z2I2 = 28 V
Z2I1 + (Z2 + Z3)I2 = 0
───────────────────
Z 2 28 V
IL = I2 =
= 3.17 103 V 137.29
Z1Z 2 + Z1Z 3 + Z 2 Z3
206
CHAPTER 17
Source Conversion:
E = (I θ)(Rp 0)
= (50 I)(40 k 0)
= 2 106 I 0
Z1 = Rs = Rp = 40 k 0
Z2 = j0.2 k
Z3 = 8 k 0
Z4 = 4 k 90
13.
I1(Z1 + Z2 + Z3) Z3I2 = E
I2(Z3 + Z4) Z3I1 = 0
────────────────────
(Z1 + Z2 + Z3)I1 Z3I2 = E
Z3I1 + (Z3 + Z4)I2 = 0
────────────────────
Z3 E
IL = I2 =
= 42.91 I 149.31
(Z1 + Z 2 + Z3 )(Z3 + Z 4 ) Z 23
14.
6Vx I1 1 k 10 V 0 = 0
10 V0 I2 4 k I2 2 k = 0
───────────────────────
Vx = I2 2 k
I1 1 k + I2 12 k = 10 V 0
I2 6 k = 10 V 0
──────────────────────
10 V 0
I2 = I 2k =
= 1.67 mA 0 = I2kΩ
6 k
I1 1 k + (1.667 mA 0)(12 k) = 10 V 0
I1 1 k + 20 V 0 = 10 V 0
I1 1 k = 10 V 0
10 V 0
= 10 mA 0
I1 = I1k =
1k
CHAPTER 17
207
E1 = 5 V 0
E2 = 20 V 0
Z1 = 2.2 k 0
Z2 = 5 k 90
Z3 = 10 k 0
I = 4 mA 0
15.
E1 I1Z1 Z2(I1 I2) = 0
Z2(I2 I1) + E2 I3Z3 = 0
───────────────────
I3 I2 = I
Substituting, we obtain:
I1(Z1 + Z2) I2Z2 = E1
I1Z2 I2(Z2 + Z3) = IZ3 E2
────────────────────
Determinants:
I1 = 1.39 mA 126.48, I2 = 1.341 mA 10.56, I3 = 2.693 mA 174.8
I10kΩ = I3 = 2.69 mA 174.8
Z1 = 1 k 0
Z2 = 4 k + j6 k
E = 10 V 0
16.
Z1(I2 I1) + E I3Z3 = 0
I1 = 6 mA 0, 0.1 Vs = I3 I2, Vs = (I1 I2)Z1
─────────────────────────────────
Substituting:
(1 k)I2 + (4 k + j6 k)I3 = 16 V 0
(99 )I2 +
I3 = 0.6 V 0
────────────────────────────
Determinants:
I3 = I6 kΩ = 1.38 mA 56.31
208
CHAPTER 17
17.
Z1 = 4 Ω 0
Z2 = 5 Ω 90
Z3 = 2 Ω 90
I1 = 3 A 0
I2 = 5 A 30
I1 = I3 + I4
1
1
1
V1 V1 V 2
V 1 + V 2 = I1
+
Z1
Z2
Z1 Z 2
Z2
or V1[Y1 + Y2] V2[Y2] = I1
I1 =
I4 = I5 + I2
1
1
1
V1 V 2 V 2
=
+ I 2 V 2 + V1 = I 2
Z2
Z3
Z2
Z 2 Z3
or V2[Y2 + Y3] V1[Y2] = I2
Y2V2 = I1
[Y1 + Y2]V1
Y2V1 + [Y2 + Y3]V2 = I2
──────────────────────
[Y2 + Y3 ] I1 Y2 I 2
V1 =
= 14.68 V 68.89
Y1 Y2 + Y1 Y3 + Y2 Y3
[Y1 + Y2 ] I 2 + Y2 I1
= 12.97 V 155.88
V2 =
Y1 Y2 + Y1 Y3 + Y2 Y3
18.
Z1 = 3 + j4 = 5 53.13
Z2 = 2 0
Z3 = 6 0 8 90
= 4.8 36.87
I1 = 0.6 A 20
I2 = 4 A 80
0 = I1 + I3 + I4 + I2
0 = I1 + V1 + V1 V 2 + I 2
Z1
Z2
1
1
1
V1 + V 2 = I1 I 2
Z1 Z 2
Z2
or
V1[Y1 + Y2] V2[Y2] = I1 I2
──────────────────────
I2 + I4 = I5
V V2 V2
=
I2 + 1
Z2
Z3
CHAPTER 17
209
1
1
1
V2
+
V1 = + I 2
Z2
Z 2 Z3
or
V2[Y2 + Y3] V1[Y2] = I2
──────────────────
and
[Y1 + Y2]V1 Y2V2 = I1 I2
Y2V1 + [Y2 + Y3]V2 = I2
Applying determinants:
[ Y 2 + Y 3][I1 + I 2] + Y 2I 2
= 5.12 V 79.36
Y1Y 2 + Y1Y 3 + Y 2 Y 3
Y1I 2 I1Y 2
V2 =
= 2.71 V 39.96
Y1Y 2 + Y1Y 3 + Y 2 Y 3
V1 =
19.
Z1 = 5 0
Z2 = 6 90
Z3 = 4 90
Z4 = 2 0
E = 30 V 50
I = 0.04 A 90
I1 = I2 + I3
1
1
1 V
E1 V1 = V1 + (V1 V 2)
+ 2 = E1
V1 +
Z1
Z2
Z3
Z1
Z1 Z 2 Z3 Z 3
or V1[Y1 + Y2 + Y3] Y3V2 = E1Y1
I3 + I = I4
V1 V 2
Z3
+I=
1
1 V
V2
V2 + 1 = I
Z4
Z3 Z4 Z3
or V2[Y3 + Y4] V1Y3 = I
resulting in
V1[Y1 + Y2 + Y3] V2Y3 = E1Y1
V1[Y3] + V2[Y3 + Y4] = +I
──────────────────────
Using determinants:
V1 = 19.86 V 43.8 and V2 = 8.94 V 106.9
210
CHAPTER 17
20.
Z1 = 10 0
Z2 = 10 0
Z3 = 4 90
Z4 = 2 0
Z5 = 8 90
E = 50 V 120
I = 0.8 A 70
I1 = I2 + I5
1
1
1
1
1
1 E
E V1
(V1 V 2)
V
V V2
= 1 +
+ 1
V1 +
+
+ V2
+
=
Z1
Z2
Z5
Z3
Z 5 Z1
Z1 Z 2 Z 3 Z 5
Z3
or V1[Y1 + Y2 + Y3 + Y5] V2[Y3 + Y5] = E1Y1
I3 + I5 = I4 + I
1
1
1
1
1
V1 V 2 V1 V 2 V 2
+
=
+ I V2 +
+ V1
+
= I
Z3
Z5
Z4
Z3 Z 4 Z5
Z3 Z5
or V2[Y3 + Y4 + Y5] V1[Y3 + Y5] = I
resulting in
V1[Y1 + Y2 + Y3 + Y5] V2[Y3 + Y5] = E1Y1
V1[Y3 + Y5] + V2[Y3 + Y4 + Y5] = I
───────────────────────────────
Applying determinants:
V1 = 19.78 V 132.48 and V2 = 13.37 V 98.78
21.
Z1 = 15 0
Z2 = 10 90
Z3 = 15 0
Z4 = 3 + j4
1
1
1 1
1
+
V2 +
V1
V3 = 0
Z3
Z1 Z 2 Z 3 Z1
1
1
1
1
1
+
+
220 V 0
100 V 90 = 0
V2
15
15 j10 15 15
3
3
V 2 133.34 10 j100 10 14.67 j 6.67
V2
16.05 V 24.55
= 96.30 V 12.32
166.67 103 36.37
V1 = E1 = 220 V 0, V3 = E2 = 100 V 90
CHAPTER 17
211
22.
E1 = 25 V 0
E2 = 75 V 20
Z1 = 10 + j20
Z2 = 6 0
Z3 = 5 0
Z4 = 20 90
Z5 = 10 0
Z6 = 80 0
Z7 = 15 90
Z8 = 5 j20 Ω
V1: V1 V 2 + V1 V 4 + V1 E1 = 0
Z1
Z2
Z3
V2: V 2 V1 + V 2 V 4 + V 2 E 2 V 3 = 0
Z1
Z4
Z6
+
V 3 E2 V 2 V 3 V 4 V 3
+
+
=0
V3:
Z6
Z7
Z8
V4: V 4 V1 + V 4 V 2 + V 4 V 3 + V 4 = 0
Z2
Z4
Z7
Z5
───────────────────────
Rearranging:
1
1
1
V
V
E
V1 +
+ 2 4 = 1
Z1 Z 2
Z3
Z1 Z 2 Z 3
1
1
1 V1 V 4 V 3
= E2
V2 +
+
Z6
Z1 Z 4 Z 6
Z1 Z 4 Z 6
1
1
1
V
V
E
V3
+
+ 2 4 = 2
Z6 Z 7
Z6
Z 6 Z 7 Z8
1
1
1
1
V V
V
V4
+
+
+ 1 2 3 =0
Z 2 Z 4 Z7 Z5 Z 2 Z 4 Z 7
Setting up and then using determinants:
V1 = 14.62 V 5.86, V2 = 35.03 V 37.69
V3 = 32.4 V 73.34, V4 = 5.67 V 23.53
212
CHAPTER 17
23.
1
4 Ω 0°
= 0.25 S 0
1
Y2 =
1 Ω 90
= 1 S 90
1
Y3 =
5 0
= 0.2 S 0
1
Y4 =
4 90
= 0.25 S 90
1
Y5 =
8 Ω 90°
= 0.125 S 90
I1 = 2 A 30
I2 = 3 A 150
Y1 =
V1[Y1 + Y2] Y2V2 = I1
V2[Y2 + Y3 + Y4] Y2V1 Y4V3 = I2
V3[Y4 + Y5] Y4V2 = I2
───────────────────────────
Y2 V2
+ 0 = I1
[Y1 + Y2]V1
Y2V1 + [Y2 + Y3 + Y4]V2
Y4 V3 = I2
0
Y4 V2 + [Y4 + Y5]V3 = I2
────────────────────────────────────
2
I1 (Y 2 + Y 3 + Y 4)(Y 4 + Y 5) Y 4 I 2[Y 2 Y5]
V1 =
Y1 + Y 2 (Y 2 + Y3 + Y 4)(Y 4 + Y 5) Y 24 Y 22(Y 4 + Y5) = Y
= 5.74 V 122.76
( + )
( + )
V2 = I1Y 2 Y 4 Y 5 I 2 Y 5 Y1 Y 2 = 4.04 V 145.03
Y
2
I 2 (Y1 + Y 2)(Y 3 + Y 4) Y 2 Y 2 Y 4I1
V3 =
= 25.94 V 78.07
Y
CHAPTER 17
213
24.
1
4 Ω 0°
= 0.25 S 0
1
Y2 =
6 0
= 0.167 S 0
1
Y3 =
8 0
= 0.125 S 0
1
Y4 =
2 90
V1[Y1 + Y2 + Y3] Y2V2 Y3V3 = I1
= 0.5 S 90
V2[Y2 + Y4 + Y5] Y2V1 Y4V3 = 0
1
Y5 =
V3[Y3 + Y4 + Y6] Y3V1 Y4V2 = I2
5 90
───────────────────────────
= 0.2 S 90
Y2V2
Y3V3 = I1
[Y1 + Y2 + Y3]V1
1
Y2V1 + [Y2 + Y4 + Y5]V2
Y4V3 = 0
Y6 =
4 90
Y3V1
Y4V2 + [Y3 + Y4 + Y6]V3 = I2
= 0.25 S 90
──────────────────────────────────────────
I1 = 4 A 0
I2 = 6 A 90
I ( Y + Y + Y )( Y + Y + Y ) Y I Y Y + Y ( Y + Y + Y )
V1 =
Y = ( Y Y + Y ) ( Y + Y + Y )( Y Y + Y ) Y Y Y ( Y + Y + Y )+ Y Y Y Y Y + Y ( Y + Y + Y )
Y1 =
2
1
2
4
5
3
4
6
4
2
2
4
3
3
4
5
2
1
2
3
2
4
5
3
4
6
4
2
2
3
4
6
3
4
3
2
4
3
2
4
5
= 15.13 V 1.29
I1 (Y 2)(Y 3 + Y 4 + Y 6)+ Y 3Y 4 +I 2 Y 4(Y1 + Y 2 + Y 3) Y 2 Y 3
V2 =
= 17.24 V 3.73
Y
2
I1 (Y3)(Y 2 + Y 4 + Y 5) + Y 2 Y 4 + I 2 Y 2 - (Y1 + Y 2 + Y 3)(Y 2 + Y 4 + Y5)
V3 =
Y
= 10.59 V 0.11
25.
Left node:
V1
Ii Io
4Ix = Ix + 5 mA 0 +
V1 V 2
2 k
Right node: V2
Ii I o
8 mA 0 =
V2
V V1
+ 2
+ 4I x
1k
2 k
V1
4 k 90
Rearrange, reduce and 2 equations with 2 unknowns result:
V1[1.803 123.69] + V2 = 10
V1[2.236 116.57] + 3 V2 = 16
──────────────────────
Determinants:
V1 = 4.37 V 128.66
V2 = V1k = 2.25 V 17.63
Insert Ix =
214
CHAPTER 17
Z1 = 1 kΩ 0
Z2 = 2 kΩ 90
Z3 = 3 kΩ 90
I1 = 12 mA 0
I2 = 4 mA 0
E = 10 V 0
26.
Ii Io
V1 V 2
+
+ I2
Z1 Z 3
and V1 + V 2 = I1 I2
Z1 Z 3
with V2 V1 = E
0 = I1 +
Substituting and rearranging:
1
1
E
V1 + = I1 I2
Z3
Z1 Z 3
and solving for V1:
V1 = 15.4 V 178.2
with V2 = VC = 5.41 V 174.87
27.
Left node: V1
Ii Io
2 mA 0 = 12 mA 0 +
and 1.5 V1 V2 = 10
Right node: V2
Ii I o
V1
V V2
+ 1
2 k
1k
V 2 V1 V 2 6 V x
1k
3.3 k
and 2.7 V1 3.7 V2 = 6.6
0 = 2 mA 0 +
Using determinants:
CHAPTER 17
V1 = V2k = 10.67 V 0 = 10.67 V 180
V2 = 6 V 0 = 6 V 180
215
Z1 = 2 k 0
Z2 = 1 k0
Z3 = 1 k 0
I = 5 mA 0
28.
V1
V
+ 3I1 + 2
Z1
Z3
with I1 = V1 V 2
Z2
and V2 V1 = 2Vx = 2V1 or V2 = 3V1
V1: I =
Substituting will result in:
or
and
with
29.
1
1
3
3
V1 + + 3 V1 = I
Z1 Z 2
Z3 Z 2
1
6
3
+ =I
V1
Z1 Z 2 Z 3
V1 = Vx = 2 V 0
V2 = 6 V 0
Ei
= 1 103 Ei
R1 0
1
= 0.02 mS 0
Y1 =
50 k
1
= 1 mS 0
Y2 =
1k
Y3 = 0.02 mS 0
I2 = (V1 V2)Y2
I1 =
V1(Y1 + Y2) Y2V2 = 50I1
V2(Y2 + Y3) Y2V1 = 50I2 = 50(V1 V2)Y2 = 50Y2V1 50Y2V2
────────────────────────────────────────────
(Y1 + Y2)V1 Y2V2 = 50I1
51Y2V1 + (51Y2 + Y3)V2 = 0
───────────────────────
(50)(51)Y2 I1
= 2451.92 Ei
VL = V2 =
(Y1 + Y2 )(51Y2 + Y3 ) 51Y22
216
CHAPTER 17
30.
a.
b.
yes
Z1 = Z 2
Z3
Z4
3
8 103 0
5 10 0
=
2.5 103 90
4 103 90
2 90 = 2 90 (balanced)
Z1 = 5 k 0, Z2 = 8 k 0
Z3 = 2.5 k 90, Z4 = 4 k 90
Z5 = 5 k 90, Z6 = 1 k 0
I1[Z1 + Z3 + Z6] Z1I2 Z3I3 = E
I2[Z1 + Z2 + Z5] Z1I1 Z5I3 = 0
I3[Z3 + Z4 + Z5] Z3I1 Z5I2 = 0
───────────────────────
[Z1 + Z3 + Z6]I1
Z1I2
Z3I3 = E
Z5I3 = 0
Z1I1 + [Z1 + Z2 + Z5]I2
Z3I1
Z5I2 + [Z3 + Z4 + Z5]I3 = 0
───────────────────────────────────────
I2 =
I3 =
E Z1( Z 3 + Z 4 + Z 5 ) + Z 3 Z 5
Z = ( Z1 + Z 3 + Z 6 )[( Z1 + Z 2 + Z 5 )( Z 3 + Z 4 + Z 5 ) Z 5 ] Z 1[ Z 1( Z 3 + Z 4 + Z 5 ) Z 3 Z 5 ] Z 3[ Z 1 Z 5 + Z 3 ( Z1 + Z 2 + Z 5 )]
2
E Z1Z5 + Z 3 (Z1 + Z 2 + Z5 )
I Z 5 = I2 I3 =
CHAPTER 17
Z
E Z1Z 4 Z 3 Z 2
Z
=
E 20 106 90 20 106 90
Z
=0A
217
c.
V1[Y1 + Y2 + Y6] Y1V2 Y2V3 = I
V2[Y1 + Y3 + Y5] Y1V1 Y5V3 = 0
V3[Y2 + Y4 + Y5] Y2V1 Y5V2 = 0
─────────────────────────
Y1V2
Y2V3 = I
[Y1 + Y2 + Y6]V1
Y1V1 + [Y1 + Y3 + Y5]V2
Y5V3 = 0
Y5V2 + [Y2 + Y4 + Y5]V3 = 0
Y2V1
─────────────────────────────────────────
V2 =
V3 =
I Y1( Y 2 + Y 4 + Y 5 ) + Y 2 Y 5
10 V 0
I = Es =
1 k 0
Rs
= 10 mA 0
1
Y1 =
5 k 0
= 0.2 mS 0
1
Y2 =
8 k 0
= 0.125 mS 0
1
Y3 =
2.5 k 90
= 0.4 mS 90
1
Y4 =
4 k 90
= 0.25 mS 90
1
Y5 =
5 k 90
= 0.2 mS 90
1
Y6 =
1 k 0
V2 = 1 mS 0
Y = ( Y1 + Y 2 Y 6 )[( Y 1 + Y 3 + Y 5)( Y 2 + Y 4 + Y 5) Y 5 ] Y1[ Y1( Y 2 + Y 4 + Y 5 ) Y 2 Y 5] Y 2[ Y 1Y 5 + Y 2( Y1+ Y 3 + Y 5 )]
2
I Y1Y5 + Y2 (Y1 +Y3 +Y5 )
Y
V Z 5 = V2 V3 =
I Y1Y4 Y4 Y3
Y
=
I 0.05 103 90 0.05 103 90
Y
=0V
31.
a.
Z1 = Z 2
Z3
Z4
3
4 10 0
4 103 0
?
3
4 10 90
4 103 90
1 90 1 90 (not balanced)
b.
The solution to 26(b) resulted in
E(Z1Z 5 Z 3 (Z1 Z 2 Z5 )
I3 = I X C =
Z
where
and
and
218
ZΔ = (Z1 + Z3 + Z6)[(Z1 + Z2 + Z5)(Z3 + Z4 + Z5) Z 52 ]
Z1[Z1(Z3 + Z4 + Z5) Z3Z5] Z3[Z1Z5 + Z3(Z1 + Z2 + Z5)]
Z1 = 5 k 0, Z2 = 8 k 0, Z3 = 2.5 k 90
Z4 = 4 k 90, Z5 = 5 k 90, Z6 = 1 k 0
I X C = 1.76 mA 71.54
CHAPTER 17
c.
The solution to 26(c) resulted in
I Y1Y5 + Y2 (Y1 +Y3 +Y5 )
V3 = VX C =
Y
YΔ = (Y1 + Y2 + Y6)[(Y1 + Y3 + Y5)(Y2 + Y4 + Y5) Y52 ]
Y1 [Y1(Y2 + Y4 + Y5) + Y2Y5]
Y2[Y1Y5 + Y2(Y1 + Y3 + Y5)]
Y1 = 0.2 mS 0, Y2 = 0.125 mS 0, Y3 = 0.4 mS 90
Y4 = 0.25 mS 90, Y5 = 0.2 mS 90
where
with
Y6 = 1 mS 0, I = 10 mA 0
V3 = VX C = 7.03 V 18.46
Source conversion:
and
32.
Z1Z4 = Z3Z2
(R1 jXC) Rx + jX Lx = R3R2
XC =
1
1
= 1 k
=
3
C (10 rad/s)(1 F)
(1 k j1 k) Rx + jX Lx = (0.1 k)(0.1 k) = 10 k
and Rx + jX Lx =
Rx = 5 , Lx =
33.
10 103
10 103
= 5 Ω + j5 Ω
=
1 103 j1 103 1.414 103 45
X Lx
=
5
= 5 mH
10 rad/s
3
1
1
1
= k
=
C (1000 rad/s)(3 F) 3
1
Z1 = R1 X C1 90 = (2 k 0) k 90 = 328.8 80.54
3
Z2 = R2 0 = 0.5 k 0, Z3 = R3 0 = 4 k 0
Z4 = Rx + j X Lx = 1 k + j6 k
X C1 =
Z1 = Z 2
Z3
Z4
328.8 80.54
0.5 k 0
?
4 k 0
6.083 80.54
82.2 10380.54 82.2 103 80.54 (balanced)
34.
Apply Eq. 17.6.
CHAPTER 17
219
35.
For balance:
R1(Rx + j X Lx ) = R2(R3 + j X L3 )
R1Rx + jR1 X Lx = R2R3 + jR2 X L3
R2 R3
R1
and R1ωLx = R2ωL3
R1Rx = R2R3 and Rx =
R1 X Lx = R2 X L3
so that Lx =
36.
R2 L3
R1
Z1 = 8 90 = j8
Z2 = 4 90 = +j4
Z3 = 8 90 = +j8
Z4 = 6 90 = j6
Z5 = 5 0
a.
Z1Z 2
= 5 38.66
+
Z1 Z 2 + Z5
Z1Z 5
= 6.25 51.34
Z7 =
Z1 + Z 2 + Z5
Z 2 Z5
Z8 =
= 3.125 128.66
Z1 + Z 2 + Z5
Z = Z7 + Z3 = 3.9 + j3.12 = 4.99 38.66
Z = Z8 + Z4 = 1.95 j3.56 = 4.06 118.71
Z Z = 10.13 67.33= 3.90 j9.35
ZT = Z6 + Z Z = 7.80 j6.23 = 9.98 38.61
120 V 0
E
=
= 12.02 A 38.61
I=
ZT 9.98 38.61
Z6 =
37.
220
12 j 9
= 4 j3
ZY = Z =
3
3
CHAPTER 17
ZT = 2 + 4 + j3 + [4 j3 + j3 ] [4 j3 + j3 ]
= 6 j3 + 2
= 8 j3 = 8.544 20.56
E
60 V 0
= 7.02 A 20.56
I=
=
8.544 20.56
ZT
ZΔ = 3ZY = 3(3 90) = 9 90
Z = 9 90 (12 j16 )
= 9 90 20 53.13
= 12.96 67.13
38.
2Z 2
2
2
= Z = [12.96 67.13] = 8.64 67.13
3
Z + 2Z 3
100 V 0
E
I=
= 11.57 A 67.13
=
ZT 8.64 67.13
ZT = Z 2Z =
39.
ZΔ = 3ZY = 3(5 ) = 15
Z1 = 15 0 5 90
= 4.74 71.57
Z2 = 15 0 6 90
= 5.57 68.2 = 2.07 + j5.17
Z3 = Z1 = 4.74 71.57
= 1.5 j4.5
ZT = Z1 (Z2 + Z3) = (4.74 71.57) (2.07 + j5.17 + 1.5 j4.5 )
= (4.74 7.57) (3.63 10.63)
= 2.71 23.87
100 V 0
E
=
= 36.9 A 23.87
I=
ZT 2.71 23.87
CHAPTER 17
221
Chapter 18
1.
Z1 = 3 0, Z2 = 8 90, Z3 = 6 90
Z2 Z3 = 8 90 6 90 = 24 90
30 V 30
E1
=
= 1.24 A 112.875
Z1 + Z 2 Z 3 3 j 24
Z3 I
(6 90)(1.24 A 112.875)
= 3.72 A 67.125
I =
=
2 90
Z 2 + Z3
I=
Z1 Z2 = 3 0 8 90 = 2.809 20.556
60 V 10
E2
=
I=
Z3 + Z1 Z 2 j 6 + 2.630 + j 0.986
= 10.597 A 72.322
I =
Z1 I
(3 0)(10.597 A 72.322)
= 3.721 A 2.878
=
Z1 + Z 2
3 + j8
I L1 = I + I = 3.72 A 67.125 + 3.721 A 2.878
= 1.446 A j3.427 A + 3.716 A + j0.187 A
= 5.162 A j3.24 A
= 6.09 A 32.12
2.
222
Z1 = 8 90, Z2 = 5 Ω 90
I = 0.3 A 60, E = 10 V 0
Z2 I
(8 90)(0.3 A 60) 2.4 A 150
I =
=
Z1 + Z 2
+ j8 j 5
3 90
= 0.8A 60
E
10 V 0
10 A 0
I =
=
Z1 + Z 2 + j8 j 5
3 90
= 3.33 A 90
IC = I I
= 0.8 A 60 3.33 A 90
= (0.4 A + j0.69 A) + j3.33 A
= 0.4 A + j4.02 A
= 4.04 A 84.32
CHAPTER 18
3.
E:
Z1 = 3 90, Z2 = 7 90
E = 10 V 90
Z3 = 6 90, Z4 = 4 0
Z = Z1 (Z3 + Z4)
= 3 90 (4 j6 )
= 3 90 7.21 56.31
= 4.33 70.56
ZE
V1 =
Z + Z 2
(4.33 70.56)(10 V 90)
=
(1.44 + j 4.08 ) j 7
43.3 V 160.56
=
= 13.28 V 224.31
3.26 63.75
13.28 V 224.31
I = V1 =
3 90
Z1
= 4.43 A 134.31
I:
CDR:
Z = Z3 + Z1 Z2
= j6 + 3 90 7 90
= j6 + 5.25 90
= j6 + j5.25
= j0.75 = 0.75 90
Z4 I
(4 0)(0.6 A 120)
2.4 A 120
=
=
I3 =
4 j 0.75
4.07 10.62
Z 4 + Z
= 0.59 A 130.62
Z2I3
(7 90)(0.59 A 130.62) 4.13 A 40.62
=
=
I =
j7 + j3
4 90
Z 2 + Z1
= 1.03 A 130.62
IL = I I (direction of I)
= 4.43 A 134.31 1.03 A 130.62
= (3.09 A + j3.17 A) (0.67 A + j0.78 A) = 2.42 A + j2.39 A
= 3.40 A 135.36
CHAPTER 18
223
4.
AC:
1
1
1
2 fC C (1000)(4.7 F)
= 212.77
XL = 2fL = L = (1000)(47 mH)
= 47
XC =
Z1 = 212.77 90, Z2 = 47 0, Z3 = 22 + j47 = 51.89 64.92
Z2 Z3 = 29.23 30.66
ZT = Z1 + Z2 Z3 = j212.77 + 25.14 + j14.91
= 25.14 j197.86 = 199.45 82.76
Is =
E
20 V 60
= 0.1 A 142.76
ZT 199.45 82.76
Z3I S
(51.89 64.92)(0.1 A 142.76) 5.19 A 207.68
22 j 47 47
83.49 34.26
Z3 Z 2
I = 62.16 mA 173.42
3
and i = 62.16 10 sin (1000t + 173.42)
I=
DC:
5V
5V
22 47 69
= 72.46 mA
I=
i = 72.46 mA + 62.16 10
5.
sin (1000t + 173.42)
DC:
AC:
224
3
(6 0)(I )
6 + 3 j1
(6 0)(4 A 0)
=
9 j1
24 A 0
=
9.055 6.34
= 2.65 A 6.34
IC =
CHAPTER 18
VC = ICXC = (2.65 A 6.34)(1 90) = 2.65 V 83.66
= 12 V + 2.65 V 83.66
υC = 12 V + 3.75 sin(ωt 83.66)
6.
E = 20 V 0
Z1 = 10 k 0
Z2 = 5 k j5 k
= 7.071 k 45
Z3 = 5 k 90
I = 5 mA 0
Z = Z1 Z2 = 10 k 0 7.071 k 45 = 4.472 k 26.57
(CDR)
(4.472 k 26.57)(5 mA 0) 22.36 mA 26.57
ZI
=
=
4 k j 2 k + j5 k
5 36.87
Z + Z 3
= 4.472 mA 63.44
I =
Z = Z2 Z3
= 7.071 k 45 5 k 90
= 7.071 k 45
ZE
(7.071 k 45)(20 V 0) 141.42 V 45
=
=
(5 k + j 5 k) + (10 k)
15.81 18.435
Z + Z1
= 8.945 V 26.565
V 8.945 V 26.565
=
= 1.789 mA 63.435 = 0.8 mA j1.6 mA
I =
5 k 90
Z3
I = I + I = (2 mA j4 mA) + (0.8 mA j1.6 mA) = 2.8 mA j5.6 mA
= 6.26 mA 63.43
(VDR)
7.
V =
Z1 = 20 k 0
Z2 = 10 k 90
I = 2 mA 0
E = 10 V 0
I =
CHAPTER 18
Z1 (hI )
(20 k 0)(100)(2 mA 0)
= 0.179 A 26.57
=
Z1 + Z 2
20 k + j10 k
225
E
10 V 0
=
22.36 k 26.57
Z1 + Z 2
= 0.447 mA 26.57
IL = I I (direction of I)
= 179 mA 26.57 0.447 mA 26.57
= 178.55 mA 26.57
I =
V:
8.
Z1 = 5 k 0, Z2 = 1 kΩ 90
Z3 = 4 k 0
V = 2 V 0, μ = 20
VL =
Z 3( V )
(4 k 0)(20)(2 V 0)
= 17.67 V 6.34
=
5 k j1 k + 4 k
Z1 + Z 2 + Z 3
I:
CDR: I =
Z1I
Z1 + Z 2 + Z 3
(5 kΩ 0)(2 mA 0)
9.056 kΩ 6.34
= 1.104 mA 6.34
=
VL = IZ3 = (1.104 mA 6.34)(4 k 0) = 4.416 V 6.34
VL = VL + VL = 17.67 V 6.34 4.416 V 6.34 = 22.09 V 6.34
9.
Z1 = 20 k 0
Z2 = 5 k + j5 k
I =
Z1 (hI )
(20 k 0)(100)(1 mA 0)
= 78.45 mA 11.31
=
Z1 + Z 2
20 k + 5 k + j 5 k
V
(20)(10 V 0)
Z1 + Z 2
25.495 k 11.31
= 7.845 mA 11.31
I =
=
IL = I I (direction of I)
= 78.45 mA 11.31 7.845 mA 11.31
= 70.61 mA 11.31
226
CHAPTER 18
Z1 = 2 k 0, Z2 = 2 k 0
VL = ILZ2
IL = hI + I = (h + 1)I
VL = (h + 1)IZ2
and by KVL: VL = IZ1 + E
V E
so that I = L
Z1
10.
V E
VL = (h + 1)IZ2 = (h + 1) L
Z2
Z1
Subt. for Z1, Z2
VL = (h + 1)(VL E)
VL(2 + h) = E(h + 1)
(h + 1)
51
VL =
E=
(20 V 53) = 19.62 V 53
(h + 2)
52
11.
I1:
I1 = 1 mA 0
Z1 = 2 k 0
Z2 = 5 k 0
KVL: V1 20 V V = 0
I =
Z
V1
21 V
I =
or V = 1 I
Z1
Z1
21
V1 = 21 V
V = I5Z2 = [I1 I]Z2
Z1
I = I1Z2 IZ2
21
Z
I 1 + Z 2 = I1Z 2
21
Z2
and I =
[I1] =
Z1
+ Z2
21
CHAPTER 18
( 5 k 0)(1 mA 0)
= 0.981 mA 0
2 k 0
+ 5 k 0
21
227
I2:
V1 = 20 V + V = 21 V
Z
V 21 V
V = 1 I
I = 1 =
Z1
Z1
21
Z1
V
I5 =
=
I
Z 2 21 Z 2
I = I2 I5 = I2
Z1
I
21 Z 2
Z
I 1 + 1 = I2
21 Z 2
2 mA 0
I2
= 1.963 mA 0
I =
=
Z1
2 k
1+
1+
21(5 k)
21 Z 2
I = I + I = 0.981 mA 0 + 1.963 mA 0
= 2.94 mA 0
12.
E1:
10 V 0 I 10 I 2 4 Vx = 0
with Vx = I 10
Solving for I:
10 V 0
= 192.31 mA 0
I=
52
Vs = 10 V 0 I(10 ) = 10 V (192.31 mA 0)(10 0) = 8.08 V 0
228
CHAPTER 18
I:
Ii Io
Vx 5 Vx
+
=
10 2
5 A + 0.1 Vx + 2.5 Vx = 0
2.6 Vx = 5 A
5
Vx =
V = 1.923 V
2.6
Vs = Vx = (1.923 V) = 1.923 V 0
Vs = Vs Vs = 8.08 V 0 + 1.923 V 0 = 10 V 0
5 A 0 +
13.
ZTh:
Z1 = 3 0, Z2 = 4 90
E = 100 V 0
ZTh = Z1 Z2 = (3 0 4 90)
= 2.4 36.87 = 1.92 + j1.44
ETh:
Z 2E
(4 90)(100 V 0)
=
Z 2 + Z1
5 53.13
= 80 V 36.87
ETh =
14.
ZTh:
ZTh = Z3 + Z1 Z2
= +j6 k + (2 k 0 3 k 90)
= +j6 k + 1.664 k 33.69
= +j6 k + 1.385 k j0.923 k
= 1.385 k + j5.077 k
= 5.26 k 74.74
ETh:
ETh =
=
CHAPTER 18
Z 2E
(3 k 90)(20 V 0)
=
Z 2 + Z1
2 k j 3 k
60 V 90
= 16.64 V 33.69
3.606 56.31
229
15.
From #31. ZTh = Z1 Z2
ZTh = ZN = 21.31 32.2
ETh = IZ = IZTh
= (0.1 A 0)(21.31 32.12)
= 2.13 V 32.2
16.
From #31. ZTh = ZN = 6.81 Ω 54.23 = 3.98 j5.53
Z1 = 2 0, Z3 = 8 90
Z2 = 4 90, Z4 = 10 0
E = 50 V 0
ETh = V2 + V4
Z2 E
V2 =
Z 2 + Z1 (Z3 + Z 4 )
( 4 90)(50 V 0)
=
+ j 4 + 2 0 (10 j8 )
= 47.248 V 24.7
V1 = E V2 = 50 V 0 47.248 V 24.7 = 20.972 V 70.285
Z 4 V1
(10 0)(20.972 V 70.285)
=
V4 =
= 16.377 V 31.625
10 j8
Z 4 + Z3
ETh = V2 + V4 = 47.248 V 24.7 + 16.377 V 31.625
= (42.925 V + j19.743 V) + (13.945 V j8.587 V)
= 56.870 V + j11.156 V = 57.95 V 11.10
17.
ZTh:
Z1 = 10 0, Z2 = 8 90
Z3 = 8 90
ZTh = Z3 + Z1 Z2
= j8 + 10 0 8 90
= j8 + 6.247 51.34
= j8 + 3.902 + j4.878
= 3.902 j3.122
= 5.00 38.66
230
CHAPTER 18
ETh: Superposition:
(E1)
(8 90)(120 V 0)
10 + j8
960 V 90
=
12.806 38.66
= 74.965 V 51.34
ETh =
(I)
ETh = VZ 2 + VZ3
= IZ3 + I(Z1 Z2)
= I(Z3 + Z1 Z2)
= (0.5 A 60)(j8 + 10 0 8 90)
= (0.5 A 60)(j8 + 3.902 + j4.878 )
= (0.5 A 60)(3.902 Ω j3.122 Ω)
= (0.5 A 60)(4.997 Ω 38.663)
= 2.499 V 21.337
ETh = ETh + ETh
= 74.965 V 51.34 + 2.449 V 21.337
= (46.83 V + j58.538 V) + (2.328 V + j0.909 V)
= 49.158 V + j59.447 V = 77.14 V 50.41
18.
ZTh:
ZTh = Z = 10 j10 = 14.14 45
ETh:
CHAPTER 18
ETh = E VZ
= 20 V 40 IZ
= 20 V 40 (0.6 A 90)(14.14 45)
= 20 V 40 8.484 V 45
= (15.321 V + j12.856 V) (6 V + j6 V)
= 9.321 V + j6.856 V
= 11.57 V 36.34
231
19.
a.
AC:
ETh:
ETh =
1
90 212.77 90
C
Z3 = 22 + L 90
= 22 + j47
= 51.89 64
Z1 =
Z 3E
(51.89 64.92)(20 V 60)
= 6.21 V 207.36
22 j 47 j 212.77
Z3 Z1
ZTh:
(212.77 90)(51.89 64.92)
j 212.77 22 j 47
= 66.04 57.36 = 35.62 + j55.61
ZTh = Z1 Z2 =
DC:
ETh:
ETh = 5 V
RTh:
RTh = 22
232
CHAPTER 18
b.
AC:
ETh
ZTh R L
6.21 V 207.36
=
35.62 j 55.61 47
6.21 V 207.36
=
82.62 j 55.61
6.21 V 207.36
=
99.59 33.94
= 62.36 mA 173.42
I=
DC:
5V
5V
22 47 69
= 72.46 mA
I=
i = 72.46 mA + 62.36 103 sin (1000t + 173.42)
matching the results of Problem 4.
20.
a.
ZTh:
ZTh = Z R1 Z R2 = 6 + 3 = 9
DC:
ETh = 12 V
AC:
ETh = IZ R1 = (4 A 0)(6 0) = 24 V 0
ETh = 12 V + 24 V 0
(DC) (AC)
CHAPTER 18
233
DC: VC = 12 V
ZC E
AC: VC =
ZC + Z RTh
b.
(1 90)(24 V 0)
j1 + 9
24 V 90
=
9.055 6.34
VC = 2.65 V 83.66
=
υC = 12 V+ 2.65 V 83.66
= 12 V + 3.75 sin(ωt 83.66)
21.
a.
ZTh:
1 Z1 = 10 k 0
5 Z2 = 5 k j5 k
= 7.071 k 45
ZTh = Z1 Z2 = (10 k 0) (7.071 k 45) = 4.47 k 26.57
Source conversion:
E1 = (Iθ)(R10) = (5 mA 0)(10 k 0) = 50 V 0
ETh =
Z 2 (E + E1 )
Z 2 + Z1
(7.071 k 45)(20 V 0 + 50 V 0)
(5 k j 5 k ) + (10 k )
(7.071 k 45)(70 V 0)
=
(15 k j 5 k )
494.97 V 45
=
15.811 18.435
= 31.31 V 26.57
=
b.
I=
ETh
31.31 V 26.565
=
ZTh + Z L 4.472 k 26.565 + 5 k 90
31.31 V 26.565
31.31 V 26.565
=
4 k j 2 k + j5 k
4 k + j3 k
31.31 V 26.565
=
= 6.26 mA 63.44
5 k 36.87
=
234
CHAPTER 18
22.
Z1 = 10 k 0
Z2 = 10 k 0
Z3 = 1 k 90
ZTh = Z3 + Z1 Z2 = 5 k j1 k 5.1 k 11.31
ETh: (VDR)
23.
ETh =
Z 2 (20 V ) (10 k 0)(20 V )
= 10 V
=
Z 2 + Z1
10 k + 10 k
ZTh:
0 Z1 = 40 k 0
.2 Z 2 = 0.2 k 90
Z 3 = 5 k 0
ZTh = Z3 (Z1 + Z2) = 5 k 0 (40 k j0.2 k) = 4.44 k 0.03
I =
Z1 (100 I )
Z1 + Z 2 + Z3
(40 k 0)(100 I )
45 k 0.255
= 88.89 I 0.255
=
ETh = IZ3 = (88.89 I 0.255)(5 k 0) = 444.45 103 I 0.26
24.
ZTh:
ZTh = Z1 = 20 k 0
ETh:
ETh = (hI)(Z1)
= (100)(2 mA 0)(20 k 0)
= 4 kV 0
CHAPTER 18
235
E:
ETh = ETh + ETh
= 4 kV 0 + 10 V 0
= 3990 V 0
25.
ZTh:
Z1 = 5 k 0
Z2 = j1
ZTh = Z1 + Z2 = 5 k j1 k
= 5.10 k 11.31
ETh:
ETh V + VZ1
= V IZ1
= (20)(2 V 0) − (2 mA 0)(5 k 0)
= −50 V 0
26.
ZTh:
Z1 = 20 k 0
Z2 = 5 k 0
ZTh = Z1 + Z2 = 25 k 0
ETh:
ETh = V (hI)(Z1)
= (20)(10 V 0) (100)(1 mA 0)(20 k 0)
= 1800 V 0
236
CHAPTER 18
27.
ETh: (Eoc)
hI = I
Z1 = 2 k 0
I = 0
and hI = 0
with Eoc = ETh = E = 20 V 53
Isc:
Isc = (h + 1)I
= (h + 1)(10 mA 53)
= 510 mA 53
ZTh =
28.
Eoc
20 V 53
= 39.22 0 (negative resistance)
=
I sc 510 mA 53
ETh:
Eoc = 21 V
Z1 = 5 k 0
V = I1Z1 = (1 mA 0)(5 k 0)
= 5 V 0
Eoc = ETh = 21(5 V 0)
= 105 V 0
V = I2Z1
= (2 mA 0)(5 k 0)
= 10 V 0
Eoc = ETh = V + 20 V = 21 V = 210 V 0
Isc:
Isc = I1
20 V = V V = 0 V
and I = 0 A
Isc = I2
Isc = Isc + Isc = 3 mA 0
Eoc = Eoc + Eoc = 315 V 0 = ETh
315 V 0
= 105 k 0
ZTh = Eoc =
3 mA 0
I sc
CHAPTER 18
237
29.
Eoc:
(ETh)
KVL: 6 Ix(2 k) Ix(1 k) + 8 V 0 Ix(3.3 k) = 0
8 V 0
= 0.491 mA 0
Ix =
16.3 k
Eoc = ETh = Ix(3.3 k) = 1.62 V 0
Isc:
8V
= 2.667 mA 0
3k
E
1.62 V 0
= 607.42 0
ZTh = oc =
2.667 mA 0
I sc
Isc =
30.
From Problem 13: ZN = ZTh = 1.92 + j1.44 = 2.4 36.87
I N:
Z1 = 3 0, Z2 = 4 90
E 100 V 0
Isc = IN =
=
3 0
Z1
= 33.33 A 0
238
CHAPTER 18
31.
Z1 = 20 + j20 = 28.284 45
Z2 = 68 0
ZN = Z1 Z2
= (28.284 45) (68 0)
= 21.31 32.2
Isc = I = IN = 0.1 A 0
32.
From Problem 17: ZN = ZTh = 5.00 38.66
I N:
Superposition:
(E1)
ZT = Z1 + Z2 Z3
= 10 + 8 90 8 90
64 0
= 10 +
0
= very large impedance
E
Is =
=0A
ZT
and V Z1 = 0 V
with V Z2 = V Z3 = E1 = 120 V 0
120 V 0
so that Isc = E1 =
90
8
Z3
= 15 A 90
(I)
Isc = I = 0.5 A 60
IN = Isc + Isc = + j15 A + 0.5 A 60 = + j15 A + 0.25 A + j0.433 A
= 0.25 A + j15.433 A = 15.44 A 89.07
CHAPTER 18
239
33.
a.
ZN:
E = 20 V 0, I2 = 0.4 A 20
Z1 = 6 + j8 = 10 53.13
Z2 = j12 = 15 53.13
ZN = Z1 Z2 = (10 53.13) (15 53.13)
= 9.66 14.93
I N:
(E)
(I2)
Isc = E/Z1 = 20 V 0/10 53.13
Isc = I2 = 0.4 A 20
= 2 A 53.13
IN = Isc + Isc = 2 A 53.13 + 0.4 A 20
= 2.15 A 42.87
34.
ZN:
E1 = 120 V 30, Z1 = 3 0
Z2 = 8 j8 , Z3 = 4 90
ZN = Z3 + Z1 Z2
= 4 90 + (3 0) (8 j8 )
= 4.37 55.67 = 2.47 + j3.61
I N:
I=
E1
120 V 30
=
ZT
Z1 +Z 2 Z3
120 V 30
3 + (8 j8 ) 4 90
120 V 30
=
6.65 46.22
= 18.05 A 16.22
=
(I )
(8 j8 )(18.05 A 16.22)
= 22.83 A 34.65
Isc = IN = Z 2
=
8 j8 + j 4
Z 2 + Z3
240
CHAPTER 18
35.
a.
Z1 = 212.77 90
Z3 = 22 + j47
= 51.89 64
AC:
I N:
E
20 V 60
= 94 mA 150
Z1 212.77 90
ZN = ZTh (problem 19) = 66.04 57.36 = 35.62 + j55.61
IN =
DC:
I N:
IN =
5V
= 227.27 mA
22
RN = RTh = (problem 19) = 22
b.
AC:
I N:
Z N (I N )
(66.04 57.36)(94 mA 150)
35.62 j 55.61 47
Z N 47
6.21 A 207.36
= 62.68 mA 173.22
=
99.08 34.14
I=
DC:
I=
3
and i = 72.46 mA + 62.68 10
Same as Problem 4 and 19.
CHAPTER 18
22 (227.27 mA)
= 72.46 mA
22 47
sin (1000t + 173.22)
241
36.
a.
From #20
ZN = ZTh = 9 0
DC:
IN =
E
RT
=
12 V
= 1.33 A
9
AC:
IN =
=
R1 I
(6 0)(4 A 0)
=
R1 + R2
9 0
24 V 0
= 2.67 A 0
9 0
IN = 1.33 A + 2.67 A 0
b.
DC: VC = IR
= (1.33 A)(9 Ω)
= 12 V
AC: Z = 9 0 1 90
= 0.994 83.66
VC = IZ = (2.667 A 0)(0.994 83.66)
= 2.65 V 83.66
VC = 12 V + 2.65 V 83.66
37.
a.
Note Problem 21(a):
ZN = ZTh = 4.47 k 26.57
Using the same source conversion: E1 = 50 V 0
Defining ET = E1 + E = 50 V 0 + 20 V 0 = 70 V 0
Z1 = 10 k 0
Z2 = 5 k j5 k = 7.071 k 45
Isc =
ET
70 V 0
= 7 mA 0
=
Z1 10 k 0
IN = Isc = 7 mA 0
242
CHAPTER 18
b.
( ) (4.472 k 26.565)(7 mA 0)
I = ZN IN =
Z N + Z L 4.472 k 26.565 + 5 k 90
31.30 mA 26.565 31.30 mA 26.565
=
=
4 j 2 + j5
4 + j3
31.30 mA 26.565
=
= 6.26 mA 63.44 as obtained in Problem 21.
5 36.87
38.
ZN:
Z1 = 10 k 0, Z2 = 10 k 0
Z3 = j1 k
ZN = Z3 + Z1 Z2 = 5 k j1 k
= 5.1 k 11.31
I N:
V2 =
(Z 2 Z 3 )20 V
(Z 2 Z 3 ) + Z1
(0.995 k 84.29)(20 V)
0.1 k j 0.99 k + 10 k
V2 = 1.961 V 78.69
=
IN = Isc =
39.
ZN:
V2 1.961 V 78.69
= 1.96 103 V 11.31
=
Z3
1 k 90
Z1 = 40 k 0, Z2 = 0.2 k 90
Z3 = 5 k 0
ZN = Z3 (Z1 + Z2)
= 5 k 0 (40 k j0.2 k)
= 4.44 k 0.03
I N:
Z1 (100 I )
Z1 + Z 2
( 40 k 0)(100 I )
=
40 k 0.286
= 100 I 0.29
IN = Isc =
CHAPTER 18
243
40.
ZN:
Z1 = 5 k 0, Z2 = 1 k 90
ZN = Z1 + Z2 = 5 k j1 k
= 5.1 k 11.31
.
IN:
V
(20)(2 V 0)
Z1 + Z 2 5.1 k 11.31
= 7.843 mA 11.31
Isc =
(I):
=
Z1 (I )
Z1 + Z 2
(5 k 0)(2 mA 0)
=
5.1 k 11.31
= 1.96 mA 11.31
Isc =
IN = Isc + Isc = 7.843 mA 11.31 + 1.96 mA 11.31
= 9.81 mA 11.31
41.
ZN:
Z1 = 20 k 0, Z2 = 5 k 0
V = 10 V 0, µ = 20, h = 100
I = 1 mA 0
ZN = Z1 + Z2 = 25 k 0
IN: (hI)
Z1 (hI )
Z1 + Z 2
(20 k 0)(hI )
=
20 k 0 + 5 k0
= 80 mA 0
Isc =
(µV)
Isc =
V
=
Z1 + Z 2
= 8 mA 0
(20)(10 V 0)
25 k
IN (direction of Isc) = Isc Isc = 80 mA 0 8 mA 0 = 72 mA 0
244
CHAPTER 18
42.
Z1 = 2 k 0
Z2 = 5 k 0
I2 = I3 + I5
V = I5Z2 = (I2 I3)Z2
Eoc = ETh = 21 V = 21(I2 I3)Z2
E
= 21 I 2 oc Z 2
Z1
Z2
Eoc 1 + 21 = 21 Z2I2
Z1
21 Z 2 I 2 21(5 k 0)(2 mA 0)
=
Eoc =
Z
5 k 0
2
1 + 21
1 + 21
Z1
2 k 0
ETh = Eoc = 3.925 V 0
20 V V V = 0
and IN = Isc = I2 = 2 mA 0
3.925 V 0
ZN = Eoc =
= 1.96 k
2 mA 0
I sc
43.
Z1 = 1 k 0
Z2 = 3 k 0
Z3 = 4 k 0
Eoc
21
Eoc
V
=
I = I1 + I2, I1 =
Z1
21 Z1
V2 = 21 V = Eoc V =
CHAPTER 18
245
I2 =
and
1
Eoc
Eoc
E
1
, I = I1 + I2 =
+ oc = Eoc
+
Z2
21 Z1
Z2
21 Z1 Z 2
+ 21 Z1
I = Eoc Z 2
21 Z1Z 2
21 Z1Z 2 I
(21)(1 k 0)(3 k 0)(2 mA 0)
=
Z 2 + 21Z1
3 k + 21(1 k 0)
ETh = Eoc = 5.25 V 0
Eoc =
Z
V3 21 V
V = 3 Isc
=
Z3
Z3
21
V = I1Z1
I = I1 + I
Isc =
Isc =
Z + Z3
Z 2 I
I = 2
I sc
Z 2 + Z3
Z2
Z3
Z + Z3
V Z 2 + Z3
+ 2
+
I sc =
I sc
Z1 Z 2
Z2
21 Z1
I
2 mA 0
= 0.79 mA 0
Isc =
=
4 k 7 k
Z3
Z3 + Z 2
+
+
21 k 3 k
Z2
21 Z1
I = I1 + I =
IN = 0.79 mA 0
E
5.25 V 0
ZN = oc =
= 6.65 k 0
I sc 0.79 mA 0
44.
Z1 = 3 + j4 , Z2 = j6
ZTh = Z1 Z2
= 5 53.13 6 90
= 8.32 3.18
ZL = 8.32 3.18 = 8.31 j0.46
246
CHAPTER 18
ETh =
Z2 E
Z 2 + Z1
(6 90)(120 V 0)
3.61 33.69
= 199.45 V 56.31
2
(3.124 V ) 2
= 1198.2 W
Pmax = E Th =
4RTh
4(8.31 )
=
Z1 = 3 + j4 = 5 53.13
Z2 = 2 Ω 0
ZN = ZTh = Z1 Z2
= 5 53.13 2 0
10 53.13
=
2 + 3 + j4
10 Ω 53.13
=
5 + j4
10 53.13
=
6.403 38.66
= 1.56 14.47
ZTh = 1.56 14.47
= 1.51 + j0.39
ZL = 1.51 j0.39
45.
ETh = I(Z1 Z2)
= (2 A 30)(1.562 14.47)
= 3.12 V 44.47
2
(3.12 V ) 2
= 1.61 W
Pmax = E Th =
4RTh 4(1.51 )
46.
ZTh:
Z1 = 4 90, Z2 = 10 0
Z3 = 5 90, Z4 = 6 90
E = 60 V 60
ZTh = Z4 + Z3 (Z1 + Z2) = j6 + (5 90) (10 + j4 )
= 2.475 j4.754
= 11.04 77.03
ZL = 11.04 77.03
CHAPTER 18
247
ETh:
ETh =
Z 3 (E )
Z3 + Z1 + Z 2
( 5 90)(60 V 60)
j5 + j 4 + 10
= 29.85 V 24.29
=
2
/ 4 RTh = (29.85 V)2/4(2.475 ) = 90 W
Pmax = E Th
47.
Z1 = 3 + j4 = 5 53.13
Z2 = j8
Z3 = 12 + j9
ZTh = Z2 + Z1 Z3 = j8 + (5 53.13) (15 36.87)
= 5.71 64.30 = 2.475 j5.143
ZL = 5.71 64.30 = 2.48 Ω + j5.15
ETh + V Z3 E2 = 0
ETh = E2 VZ3
Z3 (E 2 E1 )
Z3 + Z1
= 168.97 V 112.53
VZ3 =
ETh = E2 VZ3 = 200 V 90 168.97 V 112.53 = 78.24 V 34.16
2
/ 4 RTh = (78.24 V)2/4(2.475 ) = 618.33 W
Pmax = E Th
48.
248
E 0 1 V 0
= 1 mA 0
=
R10 1 k 0
ZTh = 40 k 0
ETh = (50 I)(40 k 0) = (50)(1 mA 0)(40 k 0) = 2000 V 0
2
( 2 kV ) 2
= 25 W
Pmax = E Th =
4 RTh 4(40 k )
I=
CHAPTER 18
49.
ETh:
Z1 = 2 k 0
Z2 = = 3 k 90
Z3 = 6 k 90
Z2E
(3 k 90)(20 V 0)
Z 2 Z1
j 3 k 2 k
60 V 90
= 16.62 V 33.69
3.61 56.31
ETh
ZTh:
ZTh Z3 Z1 Z 2
(2 k 0)(3 k 90)
2 k j 3 k
j 6 k 1.66 k 33.69
ZTh = +j6 k +
j 6 k 1.38 k j 920.8
1.38 k j 5.08 k
5.26 k 74.80
ZL = 5.36 k 74.80 = 1.38k j5.08 k
b.
50.
Pmax =
2
ETh
(16.62 V) 2
= 50.04 mW
4 RTh 4(1.38 k)
From #20, ZTh = 9 , ETh = 12 V + 24 V 0
a.
ZL = 9
b.
2
(12 V ) 2 (24 V ) 2
Pmax = E Th =
= 4 W + 16 W = 20 W
+
4 RTh 4(9 )
4(9 )
or ETh = V 02 + V12eff
2
= 26.833 V
2
(26.833 V )
and Pmax = E Th =
= 20 W
4 RTh
4(9 )
CHAPTER 18
249
51.
52.
a.
Problem 21(a):
ZTh = 4.47 k 26.57 = 4 k j2 k
ZL = 4 k + j2 k
ETh = 31.31 V 26.57
b.
2
Pmax = E Th
/ 4 RTh = (31.31 V)2/4(4 k) = 61.27 mW
a.
ZTh = 2 k 0 2 k 90 = 1 k j1 k
R L = R Th + X Th + X Load
2
2
= (1 k) 2 + (1 k + 2 k) 2
= (1 k) 2 + (1 k) 2
= 1.41 k
53.
b.
Rav = (RTh + RLoad)/2 = (1 k + 1.41 k)/2 = 1.21 k
2
(50 V ) 2
= 516.53 mW
Pmax = E Th =
4 Rav 4(1.21 k)
a.
ZTh:
1
1
=
2 fC 2 (10 kHz)(4 nF)
3978.87
XL = 2fL = 2(10 kHz)(30 mH)
1884.96
Z1 = 1 k 0, Z2 = 1884.96 90
Z3 = 3978.87 90
ZTh = (Z1 + Z2) Z3 = (1 k + j1884.96 ) 3978.87 −90)
= 2133.79 62.05 3978.87 −90)
= 3658.65 36.52
XC =
ZL = 3658.65 36.52 = 2940.27 − j2177.27
1
1
= 7.31 nF
C=
=
2 fX C 2 (10 kHz)(2177.27 )
b.
RL = RTh = 2940.27
c.
ETh
Z3 (E)
(3978.87 90)(2 V0)
=
= 3.43 V−25.53)
Z3 Z1 Z 2 1 k + j1884.96 j 3978.87
2
/ 4 RTh = (3.43 V) 2 /4(2940.27 Ω) = 1 mW
Pmax = ETh
250
CHAPTER 18
(4 k 0)(4 mA 0)
= 1.33 mA 0
4 k + 8 k
Vab = (Iab)(8 k 0) = 10.67 V 0
54.
Iab =
55.
a.
4 k(E)
1
= (20 V 0)
4 k + 12 k 4
= 5 V 0
5 V 0
= 0.83 mA 0
I=
6 k
V=
b.
6 k ( E )
1
= (20 V 0)
2
6 k + 6 k
= 10 V 0
10 V 0
= 0.83 mA 0
I=
12 k
V=
56.
100 V 0
= 50 mA 0
2 k 0
50 V 0
I2 =
4 k 90
= 12.5 mA 90
Z1 = 2 k 0
Z2 = 4 k 90
Z3 = 4 k 90
IT = I1 I2 = (50 mA 0 12.5 mA 90) = 50 mA + j12.5 mA
= 51.54 mA 14.04
Z = Z1 Z2 = (2 k 0) (4 k 90) = 1.79 k 26.57
ZIT
(1.79 k 26.57)(51.54 mA 14.04)
IC =
=
1.6 k + j 0.8 k j 4 k
Z + Z 3
= 25.77 mA 104.04
I1 =
CHAPTER 18
251
Chapter 19
1.
a.
PT = 60 W + 45 W + 25 W = 130 W
b.
QT = 0 VARS, ST = PT = 130 VA
c.
130 VA
S
= 0.542 A
ST = EIs, Is = T =
E
240 V
d.
P
60 W
= 204.2
(0.542 A ) 2
V = IsR = (0.542 A)(204.2 ) = 110.68 V
V1 = V2 = E V = 240 V 110.68 V = 129.32 V
2
2
(129.32 V ) 2
V
P1 = V 1 , R1 = 1 =
= 371.6
45 W
R1
P1
P = I s2 R, R =
2
Is
2
=
2
2
(129.32 V )
V
V2
, R2 = 2 =
= 668.9
25 W
R2
P2
V 129.32 V
V 129.32 V
= 0.193 A
= 0.348 A, I2 = 2 =
I1 = 1 =
R1 371.6
R2 668.9
P2 =
e.
2.
a.
ZT = 3 j5 + j9 = 3 + j4 = 5 53.13
50 V 0
E
I=
= 10 A 53.13
=
ZT 5 53.13
R:
L:
C:
P = I2R = (10 A)2 3 = 300 W
P=0W
P=0W
b.
R:
C:
L:
Q = 0 VAR
QC = I2XC = (10 A)2 5 = 500 VAR
QL = I2XL = (10 A)2 9 = 900 VAR
c.
R:
C:
L:
S = 300 VA
S = 500 VA
S = 900 VA
d.
PT = 300 W
QT = QL QC = 400 VAR(L)
ST =
2
2
PT + QT = EI = (50 V)(10 A) = 500 VA
300 W
= 0.6 lagging
Fp = PT =
S T 500 VA
e.
252
CHAPTER 19
f.
WR =
VI
VI VI
VI
: WR = 2 = 2
=
f1
f2
2 f1 f1
V = IR = (10 A)(3 ) = 30 V
(30 V)(10 A)
=5J
WR =
60 Hz
3.
g.
VC = IXC = (10 A)(5 ) = 50 V
VI (50 V)(10 A)
WC =
= 1.33 J
=
1 (2 )(60 Hz)
VL = IXL = (10 A)(9 ) = 90 V
VI (90 V)(10 A)
= 2.39 J
WL =
=
1
376.8
a.
PT = 0 + 100 W + 300 W = 400 W
QT = 200 VAR(L) 600 VAR(C) + 0 = 400 VAR(C)
ST =
Fp =
b.
5.
a.
PT
400 W
= 0.707 (leading)
=
ST 565.69 VA
PT = EIs cos θT
400 W = (100 V)Is(0.7071)
400 W
= 5.66 A
Is =
70.71 V
Is = 5.66 A 135
c.
4.
PT2 + QT2 = 565.69 VA
PT = 600 W + 500 W + 100 W = 1200 W
QT = 1200 VAR(L) + 600 VAR(L) 1800(C) = 0 VAR
ST = PT = 1200 VA
b.
1200 W
Fp = P T =
=1
S T 1200 VA
c.
d.
Is =
a.
PT = 200 W + 100 W + 0 + 50 W = 350 W
QT = 50 VAR(L) + 100 VAR(L) 200 VAR(C) 400 VAR(C) = 450 VAR(C)
ST =
CHAPTER 19
S T 1200 VA
= 6 A, 1 0
=
E
200 V
Is = 6 A 0
2
2
PT + QT = 570.09 VA
253
6.
350 W
PT
= 0.614 (leading)
=
S T 570.09 VA
b.
Fp =
c.
d.
PT = EIs cos θT
350 W = (50 V)Is(0.614)
350 W
= 11.4 A
Is =
30.7 V
Is = 11.4 A 52.12
a.
IR =
b.
c.
60 V 30
= 3 A 30
20 0
P = I2R = (3 A)2 20 = 180 W
QR = 0 VAR
S = P = 180 VA
60 V 30
= 6 A 60
10 90
PL = 0 W
QL = I2XL = (6 A)2 10 = 360 VAR(L)
S = Q = 360 VA
IL =
PT = 180 W + 400 W = 580 W
QT = 600 VAR(L) + 360 VAR(L) = 960 VAR(L)
ST =
(580 W) 2 + (960 VAR) 2 = 1121.61 VA
580 W
Fp = PT =
= 0.517 (lagging) θ = 58.87
1121.61
VA
ST
d.
ST = EIs
1121.61 VA
S
= 18.69 A
Is = T =
E
60 V
I s = 30 58.87 = 28.87
Is = 18.69 A 28.87
2
2
7.
a.
b.
(20 V)
R: P = E =
= 200 W
R
2
PL,C = 0 W
R:
Q = 0 VAR
C:
2
(20 V)2
= 80 VAR(C)
QC = E =
5
XC
L:
(20 V )
QL = E =
= 100 VAR(L)
4
XL
2
254
2
CHAPTER 19
S = 200 VA
S = 80 VA
S = 100 VA
c.
R:
C:
L:
d.
PT = 200 W + 0 + 0 = 200 W
QT = 0 + 80 VAR(C) + 100 VAR(L) = 20 VAR(L)
ST =
(200 W)2 + (20 VAR) 2 = 200 VA
200 W
Fp = PT =
= 0.995 (lagging) 5.73
S T 200.998 VA
8.
e.
f.
Is =
a.
S T 200.998 VA
=
= 10.05 A
E
20 V
Is = 10.05 A5.73
50 V 60
= 10 A 6.87
5 53.13
PR = I2R = (10 A)2 3 = 300 W
PL = 0 W
PC = 0 W
R L:
I=
b.
QR = 0 VAR
QL = I2XL = (10 A)2 4 = 400 VAR
50 V 60
= 5 A 150
IC =
10 90
QC = I2XC = (5 A)2 10 Ω = 250 VAR
c.
SR = P = 300 VA
SL = QL = 400 VA
SC = QC = 250 VA
d.
PT = PR = 300 W
QT = 400 VAR(L) 250 VAR(C) = 150 VAR(L)
ST =
(300 W) 2 + (150 VAR) 2 = 335.41 VA
300 W
Fp = PT =
= 0.894 (lagging)
S T 335.41 VA
e.
f.
S T 335.41 VA
=
= 6.71 A
E
50 V
0.894 26.62 lagging
θ = 60 26.62 = 33.38
Is = 6.71 A 33.38
Is =
CHAPTER 19
255
9. ac.
XL = ωL = (400 rad/s)(0.1 H) = 40
1
1
XC =
=
C (400 rad/s)(100 F)
= 25
Z1 = 40 90, Z2 = 25 90
Z3 = 30 0
ZT = Z1 + Z2 Z3 = +j40 + (25 90) (30 0)
= +j40 + 19.21 50.19
= +j40 + 12.3 j14.76
= 12.3 + j25.24
= 28.08 64.02
Is =
E
50 V 0
= 1.78 A 64.02
28.08 64.02
=
ZT
V2 = Is(Z2 Z3) = (1.78 A 64.02)(19.21 50.19)
= 34.19 V 114.21
34.19 V 114.21
I2 = V 2 =
= 1.37 A 24.21
25 90
Z2
34.19 V 114.21
= 1.14 A 114.21
I3 = V 2 =
30 0
Z3
d.
Z1:
P = 0 W, QL = I s2 X L = (1.78 A)2 40 = 126.74 VAR(L), S = 126.74 VA
Z2:
P = 0 W, QC = I 22 X C = (1.37 A)2 25 = 46.92 VAR(C), S = 46.92 VA
Z3:
P = I 32 R = (1.14 A)2 30 = 38.99 W, QR = 0 VAR, S = 38.99 VA
PT = 0 + 0 + 38.99 W = 38.99 W
QT = +126.74 VAR(L) 46.92 VAR(C) + 0 = 79.82 VAR(L)
2
2
PT + QT = 88.83 VA
ST =
38.99 W
Fp = PT =
= 0.439 (lagging)
S T 88.83 VA
e.
f.
WR =
f1 =
g.
1 400 rad/s
= 63.69 Hz
=
2
6.28
WL =
WC =
256
VR I R V2 I 3 (34.19 V)(1.14 A)
= 0.31 J
=
=
2f1
2 f1
2(63.69 Hz)
VL I L
=
(Is X L )Is
VC I C
=
V2 I 2
1
1
1
1
=
=
I s2 X L
1
=
(1.78 A) 2 40
= 0.32 J
400 rad/s
(34.19 V)(1.37 A)
= 0.12 J
400 rad/s
CHAPTER 19
10.
a.
b.
11.
12.
a.
S T 10,000 VA
=
= 50 A
E
200 V
0.5 60 leading
Is leads E by 60
E
200 V 0
ZT =
= 4 Ω 60 = 2 j3.464 = R jXC
=
50 A 60
Is
Is =
Fp = PT PT = FpST = (0.5)(10,000 VA) = 5000 W
ST
S T 5000 VA
=
= 41.67 A
E
120 V
Fp = 0.8 36.87 (lagging)
E = 120 V 0, I = 41.67 A 36.87
E
120 V 0
= 2.88 36.87 = 2.30 + j1.73 = R + jXL
Z= =
I 41.67 A 36.87
I=
b.
P = S cos θ = (5000 VA)(0.8) = 4000 W
a.
PT = 0 + 300 W = 300 W
QT = 600 VAR(C) + 200(L) = 400 VAR(C)
2
2
PT + QT = 500 VA
P
300 W
Fp = T =
= 0.6 (leading)
ST 500 VA
ST =
b.
ST 500 VA
=
= 16.67 A
E
30 V
Fp = 0.6 53.13
Is = 16.67 A 53.13
Is =
c.
d.
Load: 600 VAR(C), 0 W
R = 0, L = 0, QC = I2XC XC =
QC
2
=
600 VAR
= 2.159
(16.67 A)2
I
Load: 200 VAR(L), 300 W
C = 0, R = P/I2 = 300 W/(16.67 A)2 = 1.079
Q
200 VAR
= 0.7197
XL = 2L =
(16.67 A) 2
I
ZT = j2.159 + 1.0796 + j0.7197
= 1.08 j1.44
CHAPTER 19
257
13.
a.
PT = 0 + 300 W + 600 W = 900 W
QT = 500 VAR(C) + 0 + 500 VAR(L) = 0 VAR
ST = PT = 900 VA
Fp = PT = 1
ST
b.
Is =
c.
S T 900 VA
=
= 9 A, Is = 9 A 0
E
100 V
d.
2
Z1:
Z3:
14.
a.
4
100 V 0
= 5A 90
Z1 20 90
I2 = Is I1 = 9 A j5 A = 10.296 A 29.05
P
300 W
300
= 2.83
R = 2=
=
2
106
(10.296
A)
I
XL,C = 0
P
600 W
= 5.66
R= 2=
I 2 (10.296 A)2
Q
500
XL = 2 =
= 4.72 , XC = 0
I 2 (10.296 A)2
I1 =
Z2:
2
QC = V X C = V = 10 = 20
XC
QC 500
E
=
PT = 200 W + 30 W + 0 = 230 W
QT = 0 + 40 VAR(L) + 100 VAR(L) = 140 VAR(L)
ST =
2
2
PT + QT = 269.26 VA
230 W
= 0.854 (lagging) 31.35
Fp = PT =
S T 269.26 VA
b.
258
S T 269.26 VA
= 2.6926 A
=
E
100 V
Is = 2.69 A 31.35
Is =
CHAPTER 19
c.
2
Z2:
Z3:
15.
a.
4
R = V = 10 = 50
P 200
XL,XC = 0
100 V 0
= 2 A 0
I1 =
50 0
I2 = Is I1
= 2.6926 A 31.35 2 A 0
= 2.299 A j1.40 A 2.0 A
= 0.299 A j1.40 A
= 1.432 A 77.94
Z1:
30 W
P
Q
40 VAR
= 14.63 , XL = 2 =
= 19.50
=
2
2
I 2 (1.432 A)
I 2 (1.432 A)2
XC = 0
R=
XL =
Q 100 VAR
= 48.76 , R = 0 , XC = 0
=
I 22 (1.432 A)2
PT = 100 W + 1000 W = 1100 W
QT = 75 VAR(C) + 2291.26 VAR(C) = 2366.26 VAR(C)
ST =
2
2
PT + QT = 2609.44 VA
1100 W
= 0.422 (leading) 65.04
Fp = PT =
S T 2609.44 VA
b.
2609.44 VA
ST = EI E = S T =
= 521.89 V
I
5A
E = 521.89 V 65.07
c.
I Z1 =
S S 125 VA
= 0.2395 A
= =
V1 E 521.89 V
I Z2 =
S S 2500 VA
= 4.79 A
= =
V2 E 521.89 V
CHAPTER 19
259
Z1:
R=
100 W
P
= 1743.38
=
2
I Z1 (0.2395)2
Q = I Z21 X C X C =
Z2:
R=
XC =
16.
P
I Z21 X C
=
Q
I Z21 X C
Q
75 VAR
= 1307.53
=
2
I Z1 (0.2395 A)2
1000 W
= 43.59
(4.790 A) 2
=
2291.26 VAR
= 99.88
(4.790 A) 2
a.
0.7 45.573
P = S cos θ = (10 kVA)(0.7) = 7 kW
Q = S sin θ = (10 kVA)(0.714) = 7.14 kVAR(L)
b.
QC = 7.14 kVAR =
V2
XC
(208 V) 2
V2
= 6.059
=
Q C 7.14 kVAR
1
1
1
C=
= 438 μF
XC =
=
2 fC
2 fX C (2π)(60 Hz)(6.059 )
XC =
c.
Uncompensated:
10,000 VA
S
= 48.08 A
Is = T =
E
208 V
Compensated:
7,000 W
S
= 33.65 A
Is = T = P T =
E
E
208 V
d.
260
cos θ = 0.9
θ = cos10.9 = 25.842
x
tan θ =
7 kW
x = (7 kW)(tan 25.842)
= (7 kW)(0.484)
= 3.39 kVAR
y = (7.14 3.39) kVAR
= 3.75 kVAR
CHAPTER 19
QC = 3.75 kVAR =
XC =
C=
V2
XC
(208 V)2
V2
= 11.537
=
QC 3.75 kVAR
1
1
= 230 μF
=
2 fX C (2π)(60 Hz)(11.537 )
Uncompensated:
Is = 48.08 A
Compensated:
ST =
(7 kW) 2 + (3.39 kVAR) 2 = 7.778 kVA
S T 7.778 kVA
=
= 37.39 A
E
208 V
Is = 48.08 A 37.39 A = 10.69 A
Is =
17.
a.
PT = 5 kW, QT = 6 kVAR(L)
ST =
2
2
PT + QT = 7.81 kVA
b.
5 kW
= 0.640 (lagging)
Fp = PT =
S T 7.81 kVA
c.
Is =
d.
XC =
S T 7,810 VA
= 65.08 A
=
E
120 V
2
1
(120 V) 2
, QC = I2XC = E =
2 fC
XC
XC
and
e.
(120 V)2 14, 400
= 2.4
=
6000
QC
1
1
= 1105 μF
C=
=
2 fX C (2 )(60 Hz)(2.4 )
XC =
ST = EIs = PT
5000 W
= 41.67 A
Is = P T =
E
120 V
CHAPTER 19
261
18.
a.
Load 1:
Load 2:
P = 20,000 W, Q = 0 VAR
θ = cos10.7 = 45.573
x
10 kW
x = (10 kW)tan 45.573
= (10 kW)(1.02)
= 10,202 VAR(L)
tan θ =
Load 3:
θ = cos10.85 = 31.788
x
5 kW
x = (5 kW)tan 31.788
= (5 kW)(0.62)
= 3098.7 VAR(L)
tan θ =
PT = 20,000 W + 10,000 W + 5,000 W = 35 kW
QT = 0 + 10,202 VAR + 3098.7 VAR = 13,300.7 VAR(L)
ST =
b.
QC = QL = 13,300.7 VAR
2
(103 V)2
XC = E =
= 75.184
Q C 13,300.7 VAR
C=
c.
2
2
PT + QT = 37,442 VA = 37.442 kVA
1
1
= 35.28 μF
=
2 fX C (2π)(60 Hz)(75.184 )
Uncompensated:
37.442 kVA
S
Is = T =
= 37.44 A
E
1 kV
Compensated:
ST = PT = 35 kW
35 kW
S
= 35 A
Is = T =
E
1 kV
⌬Is = 37.44 A 35 A = 2.44 A
19.
262
a.
ZT = R1 + R2 + R3 + jXL jXC
= 2 + 3 + 1 + j3 j12 = 6 j9 = 10.82 56.31
50 V 0
E
=
= 4.62 A 56.31
I=
ZT 10.82 56.31
CHAPTER 19
b.
20.
21.
P = VI cos θ = (50 V)(4.62 A) cos 56.31 = 128.14 W
a-b: P = I2R = (4.62 A)2 2 = 42.69 W
b-c: P = I2R = (4.62 A)2 3 = 64.03 W
a-c: 42.69 W + 64.03 W = 106.72 W
a-d: 106.72 W
c-d: 0 W
d-e: 0 W
f-e: P = I2R = (4.62 A)2 1 = 21.34 W
a.
ST = 660 VA = EIs
660 VA
= 5.5 A
Is =
120 V
θ = cos10.6 = 53.13
E = 120 V 0, Is = 5.5 A 53.13
P = EI cos θ = (120 V)(5.5 A)(0.6) = 396 W
Wattmeter = 396 W, Ammeter = 5.5 A, Voltmeter = 120 V
b.
ZT =
a.
R=
E
120 V 0
= 21.82 53.13 = 13.09 + j17.46 = R + jXL
=
I
5.5 A 53.13
P
I
2
b.
R=
c.
R=
XL
49.75
= 132.03 mH
=
2 f (2π)(60 Hz)
P
I
2
P
I
2
22.
a.
=
90 W
= 10
(3 A) 2
=
E 200 V
60 W
= 100
= 15 , ZT = =
2
I
2A
(2 A)
ZT2 R 2 = (100 Ω) 2 (15 Ω)2 = 98.87
XL =
L=
E 200 V
80 W
= 50
= 5 Ω, ZT = =
2
I
4A
(4 A )
ZT2 R 2 = (50 ) 2 (5 Ω) 2 = 49.75
XL =
L=
=
XL
98.87
= 262.39 mH
=
2 f
376.8
XL = 2πfL = (6.28)(50 Hz)(0.08 H) = 25.12
R 2 + X L2 = (4 Ω) 2 + (25.12 )2 = 25.44
ZT =
60 V
= 2.358 A
Z T 25.44
P = I2R = (2.358 A)2 4 = 22.24 W
I=
CHAPTER 19
E
=
263
b.
P
30 W
= 2.07 A
=
7
R
E
60 V
= 28.99
ZT = =
I 2.07 A
I=
XL =
L=
c.
28.13 Ω
XL
=
= 89.54 mH
2 f (2π)(50 Hz)
P = I2R = (1.7 A)2 10 = 28.9 W
E 60 V
= 35.29
ZT = =
I 1.7 A
XL =
L=
264
(28.99 Ω) 2 (7 Ω) 2 = 28.13
(35.29 Ω)2 (10 Ω) 2 = 33.84
XL
38.84
= 107.77 mH
=
2 f
314
CHAPTER 19
Chapter 20
1.
a.
ωs =
s 250 rad/s
= 39.79 Hz
=
2
2
fs =
b.
ωs =
3.
1
= 3496.50 rad/s
(0.51 H)(0.16 F)
s 3496.50 rad/s
= 556.49 Hz
=
2
2
fs =
2.
1
1
=
= 250 rad/s
LC
1 H)(16 F)
1
= 22,173 rad/s
(0.27 mH)(7.5 F)
22,173 rad/s
= 3528.93 Hz
fs = s =
2
2
c.
ωs =
a.
XC = 30
d.
VR = IR = (25 mA)(10 ) = 250 mV = E
VL = IXL = (25 mA)(30 ) = 750 mV
VC = IXC = (25 mA)(30 ) = 750 mV
VL = VC
b.
ZTs = 2
c.
e.
30
Qs = X L =
= 15 (med Q)
R
2
a.
XL = 2 k
b.
I=
c.
VR = IR = (120 mA)(100 ) = 12 V = E
VL = IXL = (120 mA)(2 k) = 240 V
VC = IXC = (120 mA)(2 k) = 240 V
VL = VC = 20 VR
d.
Qs =
e.
XL = 2πfL, L =
f.
I=
E 50 mV
=
= 25 mA
2
ZTs
P = I2R = (25 mA)2 2 = 1.25 mW
E
12 V
= 120 mA
=
ZTs 100
X L 20000
=
= 20 (high Q)
R
100
XL
2 k
= 63.7 mH
=
2 f 2 (5 kHz)
1
1
1
,C=
=
= 15,920 pF
XC =
2 fC
2 fX C 2 (5 kHz)(2 k)
CHAPTER 20
265
f.
g.
4.
f s 5 kHz
= 250 Hz
=
20
Qs
BW
0.25 kHz
= 5 kHz +
= 5.13 kHz
2
2
BW
0.25 kHz
= 5 kHz
= 4.88 kHz
f1 = fs
2
2
f2 = fs +
1
L=
1
1
= 3.91 mH
=
2
(2 f s ) C (2 1.8 kHz ) 2 2 F
a.
fs =
b.
XL = 2πfL = 2π(1.8 kHz)(3.91 mH) = 44.2
1
1
=
= 44.2
XC =
2 fC 2 (1.8 kHz)(2 F)
XL = XC
c.
Erms = (0.707)(20 mV) = 14.14 mV
E
14.14 mV
= 3.01 mA
Irms = rms =
R
4.7
d.
P = I2R = (3.01 mA)2 4.7 = 42.58 μW
e.
ST = PT = 42.58 μVA
g.
h.
266
BW =
2 LC
f.
Fp = 1
44.2
Qs = X L =
= 9.4
R
4.7
f
1.8 kHz
= 191.49 Hz
BW = s =
9.4
Qs
2
1 R 1 R
4
+
+
2 2 L 2 L LC
2
1 4.7
1 4.7
4
+
+
=
2 2(3.91 mH) 2 3.91 mH (3.91 mH)(2 F)
1
601.02 11.324 103
=
2
= 1897.93 Hz
2
1 R 1 R
4
f1 =
+
+
2 2 L 2 L LC
1
601.02 11.324 103
=
2
= 1.71 kHz
1
1
PHPF = Pmax = (42.58 µW) = 21.29 μW
2
2
f2 =
CHAPTER 20
5.
6.
a.
BW = fs/Qs = 6000 Hz/15 = 400 Hz
b.
f2 = fs +
c.
Qs =
d.
PHPF =
a.
L=
b.
f2 = fs + BW/2 = 10,000 Hz + 250 Hz/2 = 10,125 Hz
f1 = fs BW/2 = 10,000 Hz 125 Hz = 9,875 Hz
c.
d.
7.
BW
= 6000 Hz + 200 Hz = 6200 Hz
2
BW
f1 = fs
= 6000 Hz 200 Hz = 5800 Hz
2
XL
XL = QsR = (15)(3 ) = 45 = XC
R
1
1
1
Pmax = (I2R) = (0.5 A)2 3 = 375 mW
2
2
2
200
XL
= 3.185 mH
=
2 f 2 (104 Hz)
R
5
=
BW =
250 Hz
2 L 2 (3.185 mH)
200
f
10,000 Hz
= 40, BW = s =
= 250 Hz
or Qs = X L = X C =
R
R
5
40
Qs
200
= 40
Qs = X L =
R
5
E 0 30 V 0
= 6 A 0, VL = (I 0)(XL 90)
=
R0 5 0
= (6 A 0)(200 90)
= 1200 V 90
VC = (I 0)(XC 90) = 1200 V 90
I=
e.
P = I2R = (6 A)2 5 = 180 W
a.
BW =
b.
Qs = X L XL = QsR = (10)(2 ) = 20
R
c.
L=
fs
Qs = fs/BW = 2000 Hz/200 Hz = 10
Qs
XL
20
=
= 1.59 mH
2 f (6.28)(2 kHz)
1
1
= 3.98 μF
C=
=
2 fX C (6.28)(2 kHz)(20 )
CHAPTER 20
267
8.
9.
d.
f2 = fs + BW/2 = 2000 Hz + 100 Hz = 2100 Hz
f1 = fs BW/2 = 2000 Hz 100 Hz = 1900 Hz
a.
BW = 6000 Hz 5400 Hz = 600 Hz
b.
BW = fs/Qs fs = QsBW = (9.5)(600 Hz) = 5700 Hz
c.
Qs =
d.
L=
XL
19
= 0.53 mH
=
2 f 2 (5700 Hz)
C=
1
1
= 1.47 μF
=
2 fX C 2 (5.7 kHz)(19 )
XL
XL = XC = QsR = (9.5)(2 ) = 19
R
E
E
5V
= 10
R=
=
R
500 mA
IM
BW = fs/Qs Qs = fs/BW = 8400 Hz/120 Hz = 70
X
Qs = L XL = QsR = (70)(10 Ω) = 700
R
XC = XL = 700
XL
700
= 13.26 mH
L=
=
2 f (2π)(8.4 kHz)
IM =
C=
1
1
= 27.07 nF
=
2 fX C (2π)(8.4 kHz)(0.7 k )
f2 = fs + BW/2 = 8400 Hz + 120 Hz/2 = 8.46 kHz
f1 = fs BW/2 = 8400 Hz 60 Hz = 8.34 kHz
10.
Qs = X L XL = QsR = 20(2 Ω) = 40 = XC
R
f
BW = s fs = QsBW = (20)(400 Hz) = 8 kHz
Qs
40
= 795.77 H
L= XL =
2 f 2 (8 kHz)
1
1
C=
= 497.36 nF
=
2 fX C 2 (8 kHz)(40 )
f2 = fs + BW/2 = 8000 Hz + 400 Hz/2 = 8200 Hz
f1 = fs BW/2 = 8000 Hz 200 Hz = 7800 Hz
11.
a.
b.
268
fs =
s 2 106 rad/s
=
= 1 MHz
2
2
f 2 f1
= 0.16 BW = f2 f1 = 0.16 fs = 0.16(1 MHz) = 160 kHz
fs
CHAPTER 20
c.
12.
2
2
(120 V)2
= 720
P= VR R= VR=
R
P
20 W
R
R
720
BW =
= 0.716 mH
L=
=
2 L
2 BW (6.28)(160 kHz)
1
1
1
fs =
C=
= 35.38 pF
= 2 6
2 2
4 f s L 4 (10 Hz ) 2(0.716 mH)
2 LC
d.
2 f s L 2 (106 Hz)(0.716 mH)
X
Q = X L = 80 R = L =
= 56.23
=
80
80
80
R
a.
Q =
XL
R
X
2 fL 2 (1MHz)(100 H)
R = L =
= 50.27
=
12.5
Q
Q
f 2 f1 1
=
= 0.2
fs
Qs
X
1
2 fL 2 (1 MHz)(100 H) 628.32
=
= 5= L =
=
0.2
R
R
R
R
628.32
= 125.66
R=
5
R = Rd + R
Qs =
125.66 = Rd + 50.27
and Rd = 125.66 50.27 = 75.39
13.
c.
XC =
a.
fp =
1
= XL
2 fC
1
1
C=
= 253.3 pF
=
2 fX C 2 (1 MHz)(628.32 )
1
2 LC
=
2
= 159.16 kHz
2 (0.1 mH)(10 nF)
b.
c.
IL =
4V
4V
VL
=
= 40 mA
=
X L 2 f p L 100
IC =
4V
4V
VL
= 40 mA
=
=
X C 1/ 2 f p C 100
CHAPTER 20
269
14.
15.
d.
2 k
2 k
=
Qp = R s =
= 20
X Lp 2 f p L 100
a.
fs =
b.
Q =
c.
Since Q 10, fp fs = 13.4 kHz
d.
XL = 2πfpL = 2π(13.4 kHz)(4.7 mH) = 395.72
1
1
= 395.91
=
XC =
2 f p C 2 (13.4 kHz)(30 nF)
XL = XC
e.
ZTp = Q2 R = (49.46)2 8 = 19.57 k
f.
VC = IZ T p = (10 mA)(19.57 k) = 195.7 V
g.
Q 10, Qp = Q = 49.46
f p 13.4 kHz
BW =
= 270.9 Hz
=
49.46
Qp
h.
IL = IC = Q IT = (49.46)(10 mA) = 494.6 mA
a.
fs =
b.
Q =
1
2 LC
=
1
= 13.4 kHz
2 (4.7 mH)(30 nF)
X L 2 fL 2 (13.4 kHz)(4.7 mH)
= 49.46 10 (yes)
=
=
8
R
R
1
2 LC
=
1
= 1.027 MHz
2 (200 H)(120 F)
XL
X
2 (1.027 MHz)(200 H)
= 86.04
R L
15
R
Q
Zp= Q2 R (15) 2 86.04 = 19.36 k
c.
270
2
2
P = I R = (120 mA) (950.9 ) = 13.69 W
CHAPTER 20
d.
XL = 2 fL 2 (1.027 MHz)(200 H) = 1.291 k
86.04 0)(114.1 V)
VR =
= 7.587 V
86.04 j1.291 k
P = VR2 / R (7.587 V)2 86.04 = 669 mW
13.69 W: 669 mW 20:1
16.
a.
Q =
X L 100
= 5 10
=
RL
20
R2 + X 2 (20 )2 + (100 ) 2
1
XL
= 104
X
=
=
=
C
100
XL
R2 + X L2 X C
b.
+
10,400
= 342.11
ZT = Rs Rp = Rs R X L = 1000
20
R
c.
E = IZTp = (5 mA 0)(342.11 0) = 1.711 V 0
2
IC =
2
E
1.711 V 0
= 16.45 mA 90
=
X C 90 104 90
ZL = 20 + j100 = 101.98 78.69
E
1.711 V 0
= 16.78 mA 78.69
IL =
=
Z L 101.98 78.69
d.
e.
17.
100
= 795.77 H
L= XL =
2 f 2 (20 kHz)
1
1
= 76.52 nF
C=
=
2 fX C 2 (20 kHz)(104 )
R 342.11
= 3.29
=
XC
104
BW = fp/Qp = 20,000 Hz/3.29 = 6079.03 Hz
Qp =
2 106
2
Hz (1 mH)
2
X
X
2000
= 57.14
Q 35 L R L
35
35
35
R
Q 10 : Q p
CHAPTER 20
fp
BW
2 106 / 2 Hz
20
100,000 Hz
271
R Q2 R R (35) 2 57.14
Q p 20
XL
2000
And 40,000 = R 70, 000
So R = 93.33 k use R = 91 k (standard value)
1
1
Q p 10, X C X L 2000
2 fC
2 106
2
Hz C
2
C = 250 pF use C = 240 pF (standard value)
18.
a.
fs =
1
2 LC
=
1
= 102.73 kHz
2 (80 H)(0.03 F)
2
(1.5 )2 0.03 F
C
= 102.73 kHz(.99958)
fp = fs 1 R = 102.73 kHz 1
L
80 H
= 102.69 kHz
1 2C
fm = fs 1 R = 102.73 kHz(0.99989) = 102.72 kHz
4 L
Since fs fp fm high Qp
b.
XL = 2πfpL = 2π(102.69 kHz)(80 μH) = 51.62
1
1
=
= 51.66
XC =
2 f p C 2 (102.69 kHz)(0.03 F)
XL XC
c.
ZTp = Rs Q2 R
51.62
= 34.41
Q = X L =
R
1.5
ZTp = 10 k (34.41) 21.5 = 10 k 1.776 k = 1.51 k
R s Q R Z T p 1.51 k
= 29.25
=
=
XL
X L 51.62
f
102.69 kHz
BW = p =
= 3.51 kHz
29.25
Qp
2
d.
Qp =
e.
Converting the voltage source to a current source:
E 100 V
= 10 mA
Is =
Rs 10 k
And Rs = Rp = 10 k
R s I s = 10 k (10 mA) = 8.49 mA
Then IT =
2
R s + Q R 10 k + 1.78 k
IC = IL Q IT = (34.41)(8.49 mA) = 292.14 mA
272
CHAPTER 20
19.
f.
VC = IZTp = (10 mA)(1.51 k) = 15.1 V
a.
fs =
1
2 LC
=
1
= 7.12 kHz
2 (0.5 mH)(1 F)
R2 C
(8 Ω) 2 (1 F)
= 7.12 kHz 1
= 7.12 kHz(0.9338) = 6.65 kHz
0.5 mH
L
fp = fs 1
1 (8 Ω) 2 (1 F)
1 R 2C
fm = fs 1 = 7.12 kHz 1
= 7.12 kHz (0.9839)
4 0.5 mH
4 L
= 7.01 kHz
Low Qp
b.
c.
d.
XL = 2πfpL = 2π(6.647 kHz)(0.5 mH) = 20.88
1
1
=
= 23.94
XC =
2 fC 2 (6.647 kHz)(1 F)
XC > XL (low Q)
2
2
2
2
R + X L = 500 (8 ) + (20.88 ) = 500 62.5
ZTp = Rs Rp = Rs
8
R
= 55.56
ZT p
Qp =
X Lp
BW =
e.
fp
Qp
=
55.56
= 2.32
23.94
=
6.647 kHz
= 2.87 kHz
2.32
One method: VC = IZTp = (40 mA)(55.56 ) = 2.22 V
IC =
IL =
20.
VC
2.22 V
= 92.73 mA
=
X C 23.94
VC
2.22 V
2.22 V
= 99.28 mA
=
=
R + jX L 8 + j 20.88 22.36
f.
VC = 2.22 V
a.
ZT p =
R2 + X L2
= 50 k
R
(50 )2 + X L2 = (50 k)(50 )
XL =
CHAPTER 20
250 104 2.5 103 = 1580.3
273
b.
Q=
X L 1580.3
= 31.61 10
=
50
R
XC = XL = 1580.3
21.
XL
1580.3 Ω
= 15.72 kHz
=
2 L 2π(16 mH)
c.
XL = 2πfpL fp =
d.
XC =
a.
Q = 20 > 10 fp = fs =
b.
Q =
1
1
1
C=
= 6.4 nF
=
2 f p C
2 f s X C 2 (15.72 kHz)(1580.3 )
1
2 LC
=
1
= 3558.81 Hz
2 (200 mH)(10 nF)
X L 2 fL
2 fL 2 (3558.81 Hz)(0.2 H)
R =
= 223.61
=
=
R
R
20
Q
ZTp = Rs R p = Rs Q2 R = 40 k (20)2 223.61
ZTp = 27.64 k
Converting the voltage source to a current source:
E 200 V
= 5 mA
Is
Rs 40 k
Rp = Rs = 40 k
VC = IZTp = (5 mA)(27.64 k) = 138.2 V
c.
P = I2R = (5 mA)227.64 k = 691 mW
d.
Qp =
BW =
22.
f
p
Qp
=
3558.81 Hz
= 575.86 Hz
6.18
a.
Ratio of XC to R suggests high Q system.
XL = 400 = XC
b.
Q =
c.
Qp =
BW =
274
27.64 k
R Rs R p
= 6.18
=
=
2 (3558.81 Hz)(0.2 H)
XL
XL
X L 400
= 50
=
R
8
R
XL
fp
Qp
=
Rs R p
XL
=
Rs Q 2R
XL
=
20 k (50)2 8 10 k
= 25
=
400
400
fp = QpBW = (25)(1000 Hz) = 25 kHz
CHAPTER 20
23.
d.
V C max = IZTp = (0.1 mA)(10 k) = 1 V
e.
f2 = fp + BW/2 = 25 kHz +
a.
XC =
1 kHz
= 25.5 kHz
2
1 kHz
f1 = fp BW/2 = 25 kHz
= 24.5 kHz
2
R2 + X L2
X L2 XLXC + R2 = 0
XL
X L2 100 XL + 144 = 0
XL =
( 100) (100) 2 4(1)(144)
2
104 576
= 50 48.54
2
XL = 98.54 or 1.46
= 50
b.
c.
Q =
Qp =
X L 98.54
= 8.21
=
R
12
Rs R p
X Lp
R2 + X L2
(12 ) 2 + (98.54 ) 2
40 k
R
12
=
100
XC
40 k
=
40 k 821.18 804.66
=
= 8.05
100
100
BW = fp/Qp fp = QpBW = (8.05)(1 kHz) = 8.05 kHz
=
24.
d.
VCmax = IZTp = (6 mA)(804.66 ) = 4.83 V
e.
f2 = fp + BW/2 = 8.05 kHz +
a.
1 kHz
= 8.55 kHz
2
1 kHz
f1 = fp BW/2 = 8.05 kHz
= 7.55 kHz
2
1
1
fs =
=
= 41.09 kHz
2 LC 2 (0.5 mH)(30 nF)
fp = fs 1
R2 C
(6 )2 30 nF
= 41.09 kHz 1
= 41.09 kHz(0.9978) = 41 kHz
0.5 mH
L
1 (6 ) 2(30 nF)
1 R 2C
fm = fs 1 = 41.09 kHz 1
= 41.09 kHz(0.0995)
4 0.5 mH
4 L
= 41.07 kHz
High Qp
CHAPTER 20
275
b.
80 V 0
= 4 mA 0, Rs = 20 k
20 k 0
X
2 fL 2 (41 kHz)(0.5 mH)
Q = L =
= 21.47 (high Q coil)
=
6
R
R
I=
2
2
R + X L
(6 ) 2 + (128.81 ) 2
20
k
Rs R p
R =
6
=
Qp =
2
2
(6 ) 2 + (128.81 ) 2
R + X L
X Lp
128.81
XL
20 k 2.771 k 2.434 k
=
=
= 18.86 (high Qp)
129.09
129.09
Rs
c.
ZTp = Rs Rp = 20 k 2.771 k = 2.43 k
d.
VC = IZTp = (4 mA)(2.43 k) = 9.74 V
e.
BW =
f.
XC =
fp
Qp
1
1
=
= 129.39
2 fC 2 (41 kHz)(30 nF)
V
9.736 V
= 75.25 mA
IC = C =
X C 129.39
IL =
25.
41 kHz
= 2.17 kHz
18.86
=
9.736 V
9.736 V
VC
=
= 75.50 mA
=
R + jX L 6 + j128.81 128.95
2 f p L
2 f p L 2 (20 kHz)(2 mH)
Q = X L =
= 3.14
R =
80
Q
R
R
BW = fp/Qp Qp = fp/BW = 20 kHz/1.8 kHz = 11.11
1
1
1
= 2
C=
= 31.66 nF
High Q fp fs =
2 2
4 f p L 4 (20 kHz) 2 2 mH
2 LC
Qp =
R
XC
R = QpXC =
Qp
2 f p C
=
11.11
= 2.79 k
2 (20 kHz)(31.66 nF)
= (80) 3.14 = 20.1 k
Rp R
(20.1 k)(2.793 k)
RsR p
R = Rs Rp =
Rs =
= 3.24 k
=
R p R 20.1 k 2.793 k
Rs + R p
Rp =
276
Q2 R
2
CHAPTER 20
26.
VCmax
1.8 V
= 9 k
I
0.2 mA
R p 9 k
R Rs R p R p
Qp =
= 300 = XC
=
XL =
=
=
XL
XL
XL
30
Qp
VCmax IZTp ZTp =
BW =
fp
Qp
fp = QpBW = (30)(500 Hz) = 15 kHz
L=
XL
300
= 3.18 mH
=
2 f 2 (15 kHz)
C=
1
1
= 35.37 nF
=
2 fX C 2 (15 kHz)(300 )
Qp = Q (Rs= ) =
27.
a.
=
fs =
1
2 LC
Q =
=
X
300 Ω
XL
R = L =
= 10
30
Qp
R
1
2 (200 H)(2 nF)
= 251.65 kHz
X L 2 (251.65 kHz)(200 H)
= 15.81 10
=
R
20
fp = fs = 251.65 kHz
b.
ZTp = Rs Q2 R = 40 kΩ (15.81)2 20 = 4.44 k
c.
Qp =
d.
BW =
e.
20 μH, 20 nF
fs the same since product LC the same
fs = 251.65 kHz
X
2 (251.65 kHz)(20 H)
= 1.581
Q = L =
20
R
Low Q :
Rs Q 2 R 4.444 k
=
= 14.05
XL
316.23
fp
Qp
=
251.65 kHz
= 17.91 kHz
14.05
fp = fs 1
R2 C
(20 ) 2 (20 nF)
= (251.65 kHz) 1
20 H
L
= (251.65 kHz)(0.775) = 194.93 kHz
XL = 2πfpL = 2π(194.93 kHz)(20 µH) = 24.496 Ω
R 2 + X L2 (20 )2 + (24.496 ) 2
Rp =
= 50
=
20
R
ZTp = Rs Rp = 40 k 50 = 49.94
CHAPTER 20
277
R
49.94
= 2.04
=
X L 24.496
f p 194.93 kHz
BW =
=
= 95.55 kHz
2.04
Qp
Qp =
f.
0.4 mH, 1 nF
fs = 251.65 kHz since LC product the same
2 (251.65 kHz)(0.4 mH)
Q = X L =
= 31.62 10
20
R
fp = fs = 251.65 kHz
ZTp = Rs Q2 R = 40 k (31.62)2 20 = 40 k ( 20 k) 13.33 k
Rs Q2 R 13.33 k
= 21.08
=
632.47
XL
f
251.65 kHz
= 11.94 kHz
BW = p =
Qp
21.08
Qp =
g.
h.
L 200 H
= 100 103
=
C
2 nF
L 20 H
part (e) =
= 1 103
C 20 nF
L 0.4 mH
part (f) =
= 400 103
C
1 nF
Network
L
ratio increased BW decreased.
C
Also, Vp = IZTp and for a fixed I, ZTp and therefore Vp will increase with increase in the
Yes, as
L/C ratio.
278
CHAPTER 20
Chapter 21
1.
3
= 0.1875, d2 = 1
16
Value = 103 100.1875"/1"
= 103 1.54
= 1.54 kHz
3
right: d1 = = 0.75, d2 = 1
4
Value = 103 100.75"/1"
= 103 5.623
= 5.62 kHz
a.
left: d1 =
b.
bottom:
top:
5
15
= 0.3125, d2 =
= 0.9375
16
16
Value = 101 100.3125"/ 0.9375" = 101 100.333
= 101 2.153
= 0.22 V
11
= 0.6875, d2 = 0.9375
d1 =
16
Value = 101 100.6875"/ 0.9375" = 101 100.720
= 101 5.248
= 0.52 V
d1 =
a.
5
b.
4
c.
8
d.
6
e.
1.30
f.
3.94
g.
4.75
h.
0.498
a.
1000
b.
1012
c.
1.59
d.
1.1
e.
1010
f.
1513.56
g.
10.02
h.
1,258,925.41
4.
a.
11.51
b.
−9.21
c.
5.
log10 48 = 1.68
log10 8 + log10 6 = 0.903 + 0.778 = 1.68
6.
log10 0.2 = 0.699
log10 18 log10 90 = 1.255 1.954 = 0.699
7.
log10 0.5 = 0.30
log10 2 = (0.301) = 0.30
8.
log10 27 = 1.43
3 log10 3 = 3(0.4771) = 1.43
2.
3.
CHAPTER 21
2.996
d.
9.07
279
9.
280 mW
P2
= log10
= log10 70 = 1.85
4 mW
P1
a.
bels = log10
b.
dB = 10 log10
P2
= 10(log10 70) = 10(1.845) = 18.45
P1
10.
dB = 10 log10 P 2
P1
100 W
6 dB = 10 log10
P1
0.6 = log10 x
100 W
x = 3.981 =
P1
100 W
P1 =
= 25.12 W
3.981
11.
dB = 10 log10
12.
dBm = 10 log10
dBm = 10 log10
40 W
P2
= 10 log10
= 10 log10 20 = 13.01
2W
P1
P
1 mW
120 mW
= 10 log10 120 = 20.79
1 mW
13.
dBv = 20 log10
8.4 V
V2
= 20 log10
= 20 log 10 84 = 38.49
0.1 V
V1
14.
dBυ = 20 log10
V2
V1
22 = 20 log10
Vo
20 mV
1.1 = log10 x
Vo
20 mV
Vo = 251.79 mV
x = 12.589 =
15.
280
P
0.0002 bar
0.001 bar
dBs = 20 log10
= 13.98
0.0002 bar
0.016 bar
dBs = 20 log10
= 38.06
0.0002 bar
Increase = 24.08 dBs
dBs = 20 log10
CHAPTER 21
16.
60 dBs 90 dBs
quiet
loud
60 dBs = 20 log10
P1
= 20 log10x
0.002 bar
3 = log10x
x = 1000
90 dBs = 20 log10
P2
= 20 log10y
0.002 bar
4.5 = log10y
y = 31.623 103
P1
x 0.002 bar
103
=
= P1 =
y
P2
P 2 31.623 103
0.002 bar
and P2 = 31.62 P1
18.
b.
19.
V2
0.775 V
V2
0.4 = log10
0.775 V
a.
a.
8 dB = 20 log10
V2
= 2.512
0.775 V
V2 = (2.512)(0.775 V) = 1.947 V
2
(1.947 V)2
= 6.32 mW
P= V =
R
600
V2
5 dB = 20 log10
0.775 V
V2
0.25 = log10
0.775 V
V2
= 0.562
0.775 V
V2 = (0.562)(0.775 V) = 0.436 V
2
(0.436 V) 2
V
= 0.32 mW
=
P=
600
R
Aυ =
Vo
=
Vi
XC
R
2
X C2
90 + tan1 XC/R =
1
2
R
1
XC
tan1 R/XC
1
1
= 3617.16 Hz
=
2 RC 2 (2.2 k)(0.02 F)
V
f = f c:
Aυ = o = 0.707
Vi
fc =
CHAPTER 21
281
f = 0.1fc:
At fc, XC = R = 2.2 k
1
1
1 1
XC =
=
=
= 10 2.2 k = 22 k
2 fC 2 0.1 f c C 0.1 2 f c C
Aυ =
f = 0.5fc =
1
fc :
2
XC =
Aυ =
f = 2fc:
XC =
Aυ =
f = 10fc:
XC =
Aυ =
b.
θ = tan1 R/XC
f = f c:
f = 0.1fc:
f = 0.5fc:
f = 2fc:
f = 10fc:
20.
a.
1
2
R
1
XC
=
1
2
2.2 k
+1
22 k
=
1
(.1) 2 + 1
= 0.995
1
1
= 2
= 2 2.2 k = 4.4 k
2 f cC
fc
2 C
2
1
1
=
= 0.894
2
(0.5) 2 + 1
2.2 k
+1
4.4 k
1
=
2 fC
1
1 1 1
=
= 2.2 k = 1.1 k
2 (2f c )C 2 2 f cC 2
1
2
2.2 k
+1
1.1 k
=
1
(2) 2 + 1
= 0.447
1
1 1 1
=
= 2.2 k = 0.22 k
2 (10 f c )C 10 2 f cC 10
1
2
2.2 k
+1
0.22 k
=
1
(10) 2 + 1
= 0.0995
θ = tan1 = 45
1
= 5.71
10
1
θ = tan1 2.2 k/4.4 k = tan1 = 26.57
2
θ = tan1 2.2 k/1.1 k = tan1 2 = 63.43
θ = tan1 2.2 k/0.22 k = tan1 10 = 84.29
θ = tan1 2.2 k/22 k = tan1
1
1
=
= 15.915 kHz
2 RC 2 ( 1 k )(0.01 F)
f = 2fc = 31.83 kHz
1
1
XC =
=
= 500
2 fC 2 (31.83 kHz)(0.01 F)
500
V
XC
Aυ = o =
= 0.4472
=
2
2
Vi
(1 k )2 + (0.5 k ) 2
R X
fc =
C
Vo = 0.4472Vi = 0.4472(10 mV) = 4.47 mV
282
CHAPTER 21
b.
1
1
f c = (15,915 kHz) = 1.5915 kHz
10
10
1
1
XC =
=
= 10 k
2 fC 2 (1.5915 kHz)(0.01 F)
V
10 k
XC
=
= 0.995
Aυ = o =
2
2
Vi
(1 k ) 2 + (10 k ) 2
R + XC
f=
Vo = 0.995Vi = 0.995(10 mV) = 9.95 mV
c.
21.
Yes, at f = fc, Vo = 7.07 mV
1
f c , Vo = 9.95 mV (much higher)
at f =
10
at f = 2fc, Vo = 4.47 mV (much lower)
fc = 500 Hz =
1
1
=
2 RC 2 (1.2 k )C
1
1
= 0.265 μF
=
2 Rfc 2 (1.2 k )(500 Hz)
V
1
Aυ = o =
2
Vi
R
1
XC
C=
At f = 250 Hz, XC = 2402.33 and Aυ = 0.895
At f = 1000 Hz, XC = 600.58 and Aυ = 0.4475
θ = tan1R/XC
1
At f = 250 Hz = fc, θ = 26.54
2
At f = 1 kHz = 2fc, θ = 63.41
CHAPTER 21
283
22.
1
1
=
= 67.73 kHz
2 RC 2 (4.7 k )(500 pF)
a.
fc =
b.
f = 0.1 fc = 0.1(67.726 kHz) 6.773 kHz
1
1
=
= 46.997 k
XC =
2 fC 2 (6.773 kHz)(500 pF)
V
46.997 k
XC
=
Aυ = o =
= 0.995 1
2
2
Vi
R +X
(4.7 k )2 + (46.997 k ) 2
C
c.
f = 10fc = 677.26 kHz
1
1
=
470
XC =
2 fC 2 (677.26 kHz)(500 pF)
V
470
XC
=
= 0.0995 0.1
Aυ = o =
2
2
Vi
R + XC
(4.7 k ) 2 + (470 ) 2
d.
Aυ =
Vo
= 0.01 =
Vi
XC
2
R + X C2
X C = 100 X
2
2
R +XC=
C
0.01
R2 + X C2 = 104 X C2
R2 = 104 X C2 X C2 = 9,999 X C2
R
4.7 k
47
XC =
=
9,999 99.995
1
1
1
XC =
=
f=
= 6.77 MHz
2 fC
2 X CC 2 (47 )(500 pF)
23.
a.
Aυ =
Vo
R
tan1 XC/R =
=
2
2
Vi
R XC
fc =
f = f c:
f = 2fc:
X
1+ C
R
2
tan1 XC/R
1
1
= 3.62 kHz
=
2 RC 2 (2.2 k)(0.02 F)
Vo
= 0.707
Vi
At fc, XC = R = 2.2 k
1
1
1 1 1
XC =
=
=
= 2.2 k = 1.1 k
2 fC 2 (2 f c )C 2 2 f cC 2
Aυ =
Aυ =
284
1
1
1.1 k
1+
2.2 k
2
= 0.894
CHAPTER 21
f=
1
f c:
2
f = 10fc:
1
1
= 2
= 2 2.2 k = 4.4 k
f
2 f cC
2 c C
2
1
Aυ =
= 0.447
2
4.4 k
1+
2.2 k
1
1 1 2.2 k
=
= 0.22 k
XC =
=
2 (10 f c )C 10 2 f cC
10
XC =
1
= 0.995
2
0.22 k
1+
2.2 k
1
1
= 10
XC =
= 10 2.2 k = 22 k
f
2 f cC
2 c C
10
1
= 0.0995
Aυ =
2
22
k
1+
2.2
k
Aυ =
f=
b.
f = f c,
θ = 45
f = 2fc,
θ = tan1 (XC/R) = tan1 1.1 k/2.2 k = tan1
1
f c,
2
θ = tan1
f = 10fc,
θ = tan1
f=
4.4 k
= tan1 2 = 63.43
2.2 k
0.22 k
= 5.71
2.2 k
22 k
= 84.29
2.2 k
1
f c,
10
θ = tan1
a.
f = fc: Aυ =
Vo
= 0.707
Vi
b.
fc =
f=
24.
1
f c:
10
1
= 26.57
2
1
1
=
= 15.915 kHz
2 RC 2 (10 k )(1000 pF)
f = 4fc = 4(15.915 kHz) = 63.66 kHz
1
1
=
= 2.5 k
XC =
2 fC 2 (63.66 kHz)(1000 pF)
V
R
10 k
=
Aυ = o =
= 0.970 (significant rise)
2
2
Vi
R XC
(10 k )2 + (2.5 k ) 2
CHAPTER 21
285
25.
c.
f = 100fc = 100(15.915 kHz) = 1591.5 kHz 1.592 MHz
1
1
=
= 99.972
XC =
2 fC 2 (1.592 MHz)(1000 pF)
10 k
R
=
Aυ =
= 0.99995 1
2
2
(10 k ) 2 + (99.972 ) 2
R + XC
d.
At f = fc, Vo= 0.707Vi = 0.707(10 mV) = 7.07 mV
2
(7.07 mV ) 2
Po = V o =
5 nW
R
10 k
Aυ =
fc =
Vo
=
Vi
1
X
1+ C
R
2
tan1 XC/R
1
1
1
R=
= 795.77
=
2 RC
2 f cC 2 ( 2 kHz)(0.1 F)
R = 795.77 750
47
= 797
nominal values
1
= 1996.93 Hz using nominal values
fc =
2 (797 )(0.1 F)
At
286
f = 1 kHz, Aυ = 0.458
f = 4 kHz, Aυ 0.9
θ = tan1 X C
R
f = 1 kHz, θ = 63.4
f = 4 kHz, θ = 26.53
CHAPTER 21
26.
1
1
=
= 79.58 kHz
2 RC 2 (100 k )(20 pF)
a.
fc =
b.
f = 0.01fc = 0.01(79.577 kHz) = 0.7958 kHz 796 Hz
1
1
=
= 9.997 M
XC =
2 fC 2 (796 Hz)(20 pF)
R
100 k
=
Aυ = V o =
= 0.01 0
2
2
Vi
(100 k ) 2 + (9.997 M ) 2
R + XC
c.
f = 100fc = 100(79.577 kHz) 7.96 MHz
1
1
=
= 999.72
XC =
2 fC 2 (7.96 MHz)(20 pF)
V
R
100 k
=
= 0.99995 1
Aυ = o =
2
2
Vi
(100 k ) 2 + (999.72 ) 2
R + XC
d.
Aυ =
Vo
R
= 0.5 =
Vi
R 2 + X C2
R 2 + X C2 = 2R
R2 + X C2 = 4R2
X C2 = 4R2 R2 = 3R2
3R 2 = 3R = 3 (100 k) = 173.2 k
1
1
1
f=
XC =
=
2 fC
2 X C C 2 (173.2 k )(20 pF)
f = 45.95 kHz
XC =
27.
a.
1
1
=
= 795.77 Hz
2 RC 2 (0.1 k )(2 F)
1
1
= 1.94 Hz
f c2 =
=
2 RC 2 (10 k )(8200 pF)
low-pass section:
f c1 =
high-pass section:
For the analysis to follow, it is assumed (R2 + jX C 2 ) R1 R1 for all frequencies of
interest.
At f c1 = 795.77 Hz:
VR1 = 0.707 Vi
X C2 =
|Vo | =
1
= 24.39 k
2 fC2
24.39 k (VR1 )
(10 k ) 2 + (24.39 k ) 2
= 0.925 VRi
Vo = (0.925)(0.707 Vi) = 0.654 Vi
CHAPTER 21
287
At f c2 = 1.94 kHz:
Vo = 0.707 VR1
1
= 41
2 fC1
R1Vi
100 (Vi )
= 0.925 Vi
VR1 =
=
(100 ) 2 + (41 ) 2
R12 + X C21
X C1 =
|Vo | = (0.707)(0.925 Vi) = 0.64 Vi
(1.94 kHz 795.77 Hz)
= 1.37 kHz
2
X C 1 = 58.1 , X C 2 = 14.17 k
At f = 795.77 Hz +
VR1 =
Vo =
100 (Vi )
(100 ) 2 + (58.1 )2
= 0.864 Vi
14.17 k VR1
(10 k ) 2 + (14.17 k ) 2
= 0.817 VR1
Vo = 0.817(0.864 Vi) = 0.706Vi
V
and Aυ = o = 0.706 ( maximum value)
Vi
After plotting the points it was determined that the gain should also be determined at
f = 500 Hz and 4 kHz:
f = 500 Hz:
X C1 = 159.15 , X C2 = 38.82 k,
VR1 = 0.532 Vi, Vo = 0.968 VR1
f = 4 kHz:
Vo = 0.515 Vi
X C1 = 19.89 , X C2 = 4.85 kΩ,
VR1 = 0.981 Vi, Vo = 0.437 VR1
Vo = 0.429 Vi
b.
288
Using 0.707(.706) 0.5 to define the bandwidth
BW 3.4 kHz 0.48 kHz = 2.92 kHz
and BW 2.9 kHz
2.9 kHz
with fcenter = 480 Hz +
= 1930 Hz
2
CHAPTER 21
28.
1
= 4 kHz
2 R1C1
Choose R1 = 1 k
1
1
C1 =
= 39.8 nF Use 39 nF
=
2 f1R1 2 (4 kHz)(1 k )
f1 =
1
= 80 kHz
2 R2C2
Choose R2 = 20 k
1
1
C2 =
= 99.47 pF Use 100 pF
=
2 f 2 R2 2 (80 kHz)(20 k )
f2 =
80 kHz 4 kHz
= 42 kHz
2
At f = 42 kHz, X C1 = 97.16 , X C2 = 37.89 k
Center frequency = 4 kHz +
Assuming Z2 Z1
R1 (Vi )
= 0.995Vi
|VR1 |=
R12 + X C21
|Vo | =
X C2 (VR1 )
R22 + X C21
= 0.884Vi
Vo = 0.884 VR1 = 0.884(0.995Vi) = 0.88 Vi
as f = f1: VR1 = 0.707Vi, X C2 = 221.05 k
and Vo = 0.996 VR1
so that Vo = 0.996 VR1 = 0.996(0.707Vi) = 0.704Vi
Although Aυ = 0.88 is less than the desired level of 1, f1 and f2 do define a band of frequencies
for which Aυ 0.7 and the power to the load is significant.
CHAPTER 21
289
29.
a.
b.
c.
fs =
1
2 LC
=
1
= 98.1 kHz
2 (4.7 mH)(560 pF)
XL
2 (98.1 kHz)(4.7 mH)
=
= 16.84
160 + 12
R + R
f
98.1 kHz
BW = s =
= 5.83 kHz
16.84
Qs
Qs =
R
160 (1 V)
V
= 0.93 V and Aυ = o = 0.93
Vi=
R R
172
Vi
5.83 kHz
BW
= 95.19 kHz
f1 = fs
= 98.1 kHz
Since Qs 10,
2
2
BW
f2 = fs +
= 101.02 kHz
2
At f = 95.19 kHz: XL = 2πfL = 2π(95.19 kHz)(4.7 mH) = 2.81 k
1
1
= 2.99 k
XC =
=
2 fC 2 (95.19 kHz)(560 pF)
160 (1 V 0)
160 V 0
Vo =
=
172 + j 2.81 k j 2.99 k 172 j180
160 V 0
= 0.643 V46.30
=
248.97 46.30
At f = fs: Vomax =
At f = 101.02 kHz: XL = 2πfL = 2π(101.02 kHz)(4.7 mH) = 2.98 k
1
1
XC =
= 2.81 k
=
2 fC 2 (101.02 kHz)(560 pF)
160 (1 V 0)
160 V 0
Vo =
=
172 + j 2.98 k j 2.81 k 172 + j170
160 V 0
= 0.66 V44.66
=
241.83 44.66
d.
f = fs: Vomax = 0.93 V
f = f1 = 95.19 kHz, Vo = 0.707(0.93 V) = 0.66 V
f = f2 = 101.02 kHz, Vo = 0.707(0.93 V) = 0.66 V
30.
a.
R2C
159.15 kHz
L
2 LC
2 f p L 2 (159.15 kHz)(1 mH)
X
Q = L =
= 62.5 10
=
16
R
R
fp =
1
1
ZTp = Q2 R = (62.5)2 16 = 62.5 k 4 k
and Vo Vi at resonance.
290
CHAPTER 21
However, R = 3.3 k affects the shape of the resonance curve and BW = fp/ Q cannot be
applied.
V
For Aυ = o = 0.707, | X | = R for the following configuration
Vi
For frequencies near fp, XL R and ZL = R + jXL XL
and X = XL XC.
For frequencies near fp but less than fp
XC X L
X=
XC X L
and for Aυ = 0.707
XC X L
=R
XC X L
1
and XL = 2πf1L
2 f1C
the following equation can be derived:
Substituting XC =
f12 +
1
1
f1 2
=0
2 RC
4 LC
For this situation:
1
1
= 48.23 103
=
2 RC 2 (3.3 k )(0.001 F)
1
1
= 2.53 1010
= 2
2
4 LC 4 (1 mH)(0.001 F)
and solving the quadratic equation, f1 = 135.83 kHz
BW
= fp f1 = 159.15 kHz 135.83 kHz = 22.32 kHz
and
2
BW
so that f2 = fp +
= 159.15 kHz + 18.75 kHz = 177.9 kHz
2
b.
fp
159.15 kHz
= 3.57
BW 44.64 kHz
BW = 2(18.75 kHz) = 37.5 kHz
Qp =
CHAPTER 21
=
291
31.
b.
a.
Qs =
5000
5000
XL
= 12.5
=
=
R + R 390 + 10 400
f s 5000 Hz
= 400 Hz
=
12.5
Qs
400 Hz
= 4.8 kHz
f1 = 5000 Hz
2
400 Hz
= 5.20 kHz
f2 = 5000 Hz +
2
BW =
c.
At resonance
10 (Vi )
Vo =
10 + 400
= 0.024 Vi
32.
d.
At resonance,
a.
Q =
10 Ω 2 k = 9.95 Ω
9.95 (Vi )
0.024 Vi as above!
Vo =
9.95 + 400
X L 400
= 40
=
R
10
2
2
Z T p = Q R = (40) 20 = 32 k 1 k
At resonance, Vo =
32 k Vi
= 0.97Vi
32 k + 1 k
Vo
= 0.97
Vi
For the low cutoff frequency note solution to Problem 30:
1
1
f12 +
f1 2
=0
2 RC
4 LC
1
1
C=
= 19.9 nF
=
2 fX C 2 (20 kHz)(400 )
and Aυ =
L=
XL
400
=
= 3.18 mH
2 f 2 (20 kHz)
Substituting into the above equation and solving
f1 = 16.4 kHz
BW
= 20 kHz 16.4 kHz = 3.6 kHz
with
2
and BW = 2(3.6 kHz) = 7.2 kHz
f
20 kHz
Qp = p =
= 2.78
BW 7.2 kHz
292
CHAPTER 21
b.
c.
At resonance
Z T p = 32 k 100 k = 24.24 k
24.24 k V i
= 0.96Vi
24.24 k + 1 k
V
and Aυ = o = 0.96 vs 0.97 above
Vi
with Vo =
At frequencies to the right and left of fp, the impedance Z T p will decrease and be
affected less and less by the parallel 100 k load. The characteristics, therefore, are
only slightly affected by the 100 k load.
d.
At resonance
Z T p = 32 k 20 k = 12.31 k
with Vo =
12.31 k Vi
= 0.925Vi vs 0.97 Vi above
12.31 k + 1 k
At frequencies to the right and left of fp, the impedance of each frequency will actually
be less due to the parallel 20 k load. The effect will be to narrow the resonance curve
and decrease the bandwidth with an increase in Qp.
33.
a.
fp =
1
2 LC
1
= 726.44 kHz (band-stop)
2 (400 H)(120 pF)
=
X Ls 90 + X L p 90 X C 90 = 0
jX Ls +
jX Ls +
X
90 X C 90
jX L p jX C
X Lp X C
j X Lp X C
jX Ls j
X Ls
Lp
X Lp X C
X
Lp
XC
X Lp X C
X Lp X C
=0
=0
=0
=0
X Ls X C X Ls X L p + X L p X C = 0
Lp
Ls
Ls +
=0
C
C
CHAPTER 21
293
1
Ls + L p = 0
C
Ls + L p
=
CLs L p
LsLpω2
f=
34.
a.
Ls + L p
1
2
CLs L p
1
c.
fc =
f=
f=
1
f c:
2
1
f c:
10
f = 10fc:
f=
1
f c:
2
f = 2fc:
294
Ls =
2
XL
24.15 k
= 128.19 mH
=
2 f 2 (30 kHz)
1
1
= 7.2 kHz
=
2 RC 2 (0.47 k )(0.047 F)
f = 2fc:
d.
460 106
= 2.01 MHz (pass-band)
28.8 1019
1
2
1
1
= 12.68 mH
= 2
2
4 f s C 4 (100 kHz ) 2(200 pF)
2 LC
XL = 2πfL = 2π(30 kHz)(12.68 mH) = 2388.91
1
1
=
= 26.54 k
XC =
2 fC 2 (30 kHz)(200 pF)
XC XL = 26.54 k 2388.91 = 24.15 k(C)
X Lp = X C(net) = 24.15 k
fs =
Lp =
35. a, b.
=
A dB = 20 log10
A dB = 20 log10
A dB = 20 log10
1
1+ f c /f
1
1
1 (10)2
Aυ =
1 + (0.1) 2
1 + f c /f
1
1 (0.5) 2
2
=
1
1+ (2)2
= 7 dB
= 20.04 dB
1
1
= 20 log10
= 0.969 dB
1 (0.5) 2
A dB = 20 log10
Aυ =
2
= 0.043 dB
1
1 + (2) 2
= 0.447
= 0.894
CHAPTER 21
e.
36.
a.
fc =
1
1
1
= 1.83 kHz
=
=
2 RC 2 (6.8 k 12 k )0.02 F 2 (4.34 k )(0.02 F)
Vo
1
=
Vi
1 + ( f /f ) 2
c
1
Vi
and Vo =
1 + ( f /f ) 2
c
b.
c. & d.
CHAPTER 21
295
e.
Remember the log scale! 1.5fc is not midway between fc and 2fc
A dB = 20 log10 Aυ
1.5 = 20 log10 Aυ
0.075 = log10 Aυ
V
Aυ = o = 0.84
Vi
f.
37. a, b.
θ = tan1 fc/f
Aυ =
fc =
c.
Vo
= A =
Vi
1
1 + (f/f c )
2
tan1f/fc
1
1
= 13.26 kHz
=
2 RC 2 (12 k )(1 nF)
f = fc/2 = 6.63 kHz
AdB 20 log10
1
1 + (0.5) 2
= 0.97 dB
f = 2fc = 26.52 kHz
AdB = 20 log10
1
1 + (2) 2
= 6.99 dB
f = fc/10 = 1.326 kHz
AdB = 20 log10
1
1 + (0.1) 2
= 0.04 dB
f = 10fc = 132.6 kHz
A dB = 20 log10
d.
296
f = fc/2:
Aυ =
f = 2fc:
Aυ =
1
1 + (10) 2
1
1 (0.5) 2
1
1 + (2) 2
= 20.04 dB
= 0.894
= 0.447
CHAPTER 21
38.
e.
θ = tan1 f/fc
f = fc/2:
θ = tan1 0.5 = 26.57
θ = tan1 1 = 45
f = f c:
f = 2fc:
θ = tan1 2 = 63.43
a.
R2 XC =
( R2 )( jX C )
R2 X C
= j
R2 jX C
R2 jX C
jR2 X C
Vi
R2 jX C
R2 X C Vi
Vo =
= j
R2 X C
R1 ( R2 jX C ) jR2 X C
R1 j
R2 jX C
-jR2 X C Vi
jR2 X C Vi
=
=
R1R2 jR1 X C jR2 X C R1R2 j ( R1 R2 ) X C
R2 X C Vi
R2 Vi
=
=
jR1R2 ( R1 R2 ) X C j R1R2 + ( R R )
1
2
XC
R2
Vi
R1 R2
R2 Vi
=
=
RR
R1 R2 j 1 2 1 + j R1R2 1
XC
R1 R2 X C
R2
V
R1 R2
and Aυ = o =
RR
Vi
1 + j 1 2 C
R1 R2
or Aυ =
CHAPTER 21
R2
R1 R2
1
1+ j 2 f ( R1 R2 )C
297
defining fc =
1
2 ( R1 R2 )C
1
1+ j f/f c
1
R2
and Aυ =
tan 1 f/fc
R1 R2 1+ ( f/f c )2
R2
1
|Vi |
with |Vo | =
R1 R2 1 + (f/f c ) 2
R2
27 k
for f fc, Vo =
Vi =
Vi = 0.852Vi
R1 R2
4.7 k + 27 k
Aυ =
R2
R1 R2
at f = fc: Vo = 0.852[0.707]Vi = 0.602Vi
1
1
= 1.02 kHz
fc =
2 ( R1 R2 )C 2 (4.7 k 27 k)0.039 F
b.
c. & d.
20 log10
298
4.7 k + 27 k
R1 R2
= 20 log10
27 k
R2
= 20 log10 1.174 = 1.39 dB
CHAPTER 21
e.
AdB 1.39 dB 0.5 dB = 1.89 dB
AdB = 20 log10 Aυ
1.89 = 20 log10 Aυ
0.0945 = log10 Aυ
V
Aυ = o = 0.80
Vi
f.
θ = tan1 f/fc
39.
R2' 39 k 68 k = 24.79 k
a.
From Section 21.11,
Aυ =
j f/f1
Vo
=
Vi 1 jf/f c
1
1
= 642.01 Hz
=
2 R2 C
2 (24.79 k )(0.01 F)
1
1
=
fc =
= 457.47 Hz
2 R1 + R2 C
2 (10 k + 24.79 k )(0.01 F)
f1 =
20log10
CHAPTER 21
f
f
20log10 c
f1
f1
457.5 Hz
= 20 log10
642 Hz
= −2.94 dB
299
b.
f
f
= + tan1 1
f
f1
θ = 45
θ = 54.52
θ = 90 tan1
f = f1:
f = f c:
1
f = f1 = 321 Hz, θ = 63.44
2
1
f=
f1 = 64.2 Hz, θ = 84.29
10
f = 2f1 = 1,284 Hz, θ = 26.57
f = 10f1 = 6420 Hz, θ = 5.71
40.
a.
VTh =
12 k Vi
= 0.682 Vi
12 k + 5.6 k
RTh = 5.6 k 12 k = 3.82 k
f = Hz: (C short circuit)
8.2 k (0.682 Vi )
= 0.465 Vi
Vo =
8.2 k + 3.82 k
At f c : V0 0.707(0.465 Vi ) 0.329 Vi
300
CHAPTER 21
R2 (0.682 Vi )
0.682 R2 Vi
=
R1 R2 jX C R1 R2 jX C
V
0.682 R2
j 2 f (0.682 R2 )C
and Aυ = o =
=
Vi R1 R2 jX C 1 + j 2 f ( R1 R2 )C
1
1
j f/f1
so that Aυ =
with f1 =
=
1 + j f/f c
2 0.682R2 C 2 0.682(8.2 k )(0.1 F)
= 284.59 Hz
1
1
and fc =
=
2 ( R1 R2 )C 2 (3.82 k + 8.2 k )(0.1 F)
= 132.41 Hz
voltage-divider rule: Vo =
132.41 Hz
284.59 Hz
= 20 log10 0.465 = 6.65 dB
20 log10 f/f1 = 20 log10
b.
θ = 90 tan1 f/fc = +tan1 fc/f = tan1 132.6 Hz/f
or
CHAPTER 21
301
f
f1
Aυ =
f
1 j
fc
1 j
41.
a.
1
1
= 19.41 kHz
2 R2C 2 (10 k)(820 pF)
1
1
fc =
2 ( R1 R2 )C 2 (10 k 91 k)(820 pF)
= 1.92 kHz
f1 =
20log10
R1 R2
20log10 10 = 20 dB
R2
b.
θ = tan1 f/f1 tan1 f/fc
f = 10 kHz
10 kHz
10 kHz
tan1
= 27.25 79.13 = 51.88
θ = tan1
19.41 kHz
1.92 kHz
f = fc: (f1 = 10 fc)
fc
f
θ = tan1
tan 1 c = tan 1 0.1tan 1 1 = 5.71 45 = 39.29
10 f c
fc
42.
a.
R1 no effect!
Note Section 21.12.
Vo 1 + j ( f/f1 )
=
Vi 1 + j ( f/f c )
1
f1 =
= 2.84 kHz
2 (5.6 k )(0.01 F)
1
fc =
= 904.3 Hz
2 (12 k + 5.6 k )(0.01 F)
Aυ =
Note Fig. 21.65.
Asymptote at 0 dB from 0 fc
6 dB/octave from fc to f1
12 k + 5.6 k
9.95 dB from f1 on 20 log
= 9.95 dB
5.6
k
302
CHAPTER 21
(b)
Note Fig. 21.67.
From 0 to 26.50 at fc and f1
θ = tan1 f/f1 tan1 f/fc
At f = 1500 Hz (between fc and f1)
θ = tan1 1500 Hz/2.84 kHz tan1 1500 Hz/904.3 Hz
= 27.83 58.92 = 31.09
43.
a.
V o 1 jf1/f
V i 1 jf c /f
1
1
f1 =
= 945.66 Hz
2 R1C 2 (3.3 k)(0.051 F)
1
1
= 7.59 kHz
fc =
=
2 (R1 R2 )C 2 (3.3 k 0.47 k ) (0.051 F)
0.411 k
Aυ =
20 log10
R1 R2
3.3 k + 0.47 k
= 20 log10 8.02 = 18.08 dB
= 20 log10
0.47 k
R2
b.
f
f1
+ tan1 c
f
f
f
f
f f1 : tan 1 1 tan 1 c
f1
f1
θ = tan1
7.59 kHz
945.66 Hz
45 82.89 37.89
tan 1 1 tan 1
945.66 Hz
7.59 kHz
tan 1
4 kHz
4 kHz
13.28 62.24 48.96
f 4 kHz: tan 1
f f c : tan 1
f
945.66 Hz
tan 1 c
7.59 kHz
fc
tan 1 0.125 tan 1 1
7.11 45 37.89
CHAPTER 21
303
44.
a.
Note Section 21.13.
1 j ( f1 /f )
Aυ =
1 j (f c /f )
f1 =
fc =
1
1
= 964.58 Hz
=
2 R1C 2 (3.3 k )(0.05 F)
1
1
= 7334.33 Hz
=
2 ( R1 R2 )C 2 (3.3 k 0.5 k ) 0.05 F
0.434 k
Note Fig. 21.72.
20 log10
3.3 k + 0.5 k
R1 R2
= 17.62 dB
= 20 log10
0.5 k
R2
Asymptote at 17.62 dB from 0 f1
+6 dB/octave from f1 to fc
0 dB from fc on
b.
θ = tan1 f1/f + tan1 fc/f
Test at 3 kHz
θ = tan1 964.58 Hz/3.0 kHz + tan1 7334.33 Hz/3.0 kHz
= 17.82 + 67.75 = 49.93 50
Therefore rising above 45 at and near the peak
50 kHz vs 23 kHz drop about 1 dB at 23 kHz due to 50 kHz break.
Ignore effect of break frequency at 10 Hz.
Assume 2 dB drop at 68 Hz due to break frequency at 45 Hz.
Rough sketch suggests low cut-off frequency of 90 Hz.
Checking: Ignoring upper terms
2
2
10 Hz
45 Hz
68 Hz
A dB 20 log10 1 +
20 log10 1 +
20 log10 1 +
f
f
f
= −0.0532 dB − 0.969 dB − 1.96 dB
= −2.98 dB (excellent)
304
2
CHAPTER 21
High frequency cutoff: Try 20 kHz
2
f
f
A dB = 20log10 1 +
20 log10 1 +
23 kHz
50 kHz
= −2.445 dB − 0.6445 dB
= −3.09 dB (excellent
BW = 20 kHz 90 Hz = 19,910 Hz
2
20 kHz
f1 = 90 Hz, f2 = 20 kHz
Testing: f = 100 Hz
f
f
10 Hz
45 Hz
68 Hz
+ tan 1
+ tan 1
tan 1
tan 1
23 kHz
50 kHz
f
f
f
= tan1 0.1 + tan1 0.45 + tan1 0.68 tan1 0.00435 tan1 .002
= 5.71 + 24.23 + 34.22 0.249 0.115
= 63.8 vs about 65 on the plot
θ = tan 1
45.
a.
1
A
=
100 Hz
130 Hz
f
f
A max
1 j
1 j
1 + j
1 + j
20 kHz
50 kHz
f
f
Proximity of 100 Hz to 130 Hz will raise lower cutoff frequency above 130 Hz:
Testing: f = 180 Hz: (with lower terms only)
2
A dB
100
130
= 20 log10 1
20 log10 1
f
f
2
100
130
= 20 log10 1
20 log10 1
180
180
= 1.17 dB 1.82 dB = 2.99 dB 3 dB
CHAPTER 21
2
2
305
Proximity of 50 kHz to 20 kHz will lower high cutoff frequency below 20 kHz:
Testing: f = 18 kHz: (with upper terms only)
2
f
f
A dB = 20 log10 1
20 log10 1
20 kHz
50 kHz
2
18 kHz
13 kHz
= 20 log10 1 +
20 log10 1 +
20 kHz
20 kHz
= 2.576 dB 0.529 dB = 3.105 dB
2
2
b.
Testing:
f = 1.8 kHz:
100
130
1.8 kHz
1.8 kHz
+ tan 1
tan 1
tan 1
1.8 kHz
1.8 kHz
20 kHz
50 kHz
= 3.18 + 4.14 5.14 2.06
= 0.12 0
θ = tan1
47.
flow = fhigh BW = 36 kHz 35.8 kHz = 0.2 kHz = 200 Hz
Aυ =
306
120
50
200
f
1 j 1 j
1 j
36 kHz
f
f
CHAPTER 21
0.05
1
1
+jf
=
=
=
100
100
2000 +jf + 2000
0.05 j
1 j
1 j
f
0.05 f
f
f
+j
2000 and f = 2000 Hz
=
1
f
1+ j
2000
48.
Aυ =
49.
Aυ =
50.
Aυ =
200
1
1
200 j 0.1 f 1 j 0.1 f 1 j f
200
2000
1
f
,
= 1 and f = 2 kHz
A dB = 20 log 20
2
f 2000
1+
2000
jf/ 1000
(1 + jf/ 1000)(1 + jf/10,000)
CHAPTER 21
307
51.
f
f
1 j
1 j
1000
2000
Aυ =
2
f
j
1
3000
2
2
f
f
AdB = 20 log10 1 + 1 + 20 log10 1 + 2 + 40 log10
1000
2000
52.
308
1
f
1+ 3
3000
2
j
2 f
f
f
j
f
= j
= j
= j
,
= j
1000
1000
1000
159.16 Hz 5000
795.78 Hz
2
CHAPTER 21
53.
a.
b.
Woofer − 400 Hz:
XL = 2πfL = 2π(400 Hz)(4.7 mH) = 11.81
1
1
=
= 10.20
XC =
2 (400 Hz)(39 F)
2 fC
R XC = 8 0 10.2090 = 6.3 38.11
( R X C )(Vi )
(6.3 38.11)(Vi )
=
Vo =
( R X C ) jX L
(6.3 38.11) j 11.81
Vo = 0.673 96.11 Vi
V
and Aυ = o = 0.673 vs desired 0.707 (off by less than 5%)
Vi
Tweeter − 5 kHz:
XL = 2πfL = 2π(5 kHz)(0.39 mH) = 12.25
1
1
=
= 11.79
XC =
2 fC 2 ( 5 kHz)(2.7 F)
R XL = 8 0 12.25 90 = 6.7 33.15
(6.7 33.15)(Vi )
Vo =
(6.7 33.15) j 11.79
Vo = 0.678 88.54 Vi
V
and Aυ = o = 0.678 vs 0.707 (off by less than 5%)
Vi
Woofer − 3 kHz:
XL = 2πfL = 2π(3 kHz)(4.7 mH) = 88.59
1
1
=
= 1.36
XC =
2 fC 2 ( 3 kHz)(39 F)
R XC = 8 0 1.36 90 = 1.341 80.35
( R X C )(Vi )
(1.341 80.35)(Vi )
Vo =
=
( R X C ) jX L (1.341 80.35) j 88.59
Vo = 0.015 170.2 Vi
V
and Aυ = o = 0.015 vs desired 0 (excellent)
Vi
Tweeter − 3 kHz:
XL = 2πfL = 2π(3 kHz)(0.39 mH) = 7.35
1
1
=
= 19.65
XC =
2 fC 2 (3 kHz)(2.7 F)
R XL = 8 0 7.35 90 = 5.42 47.42
( R X L )(Vi )
(5.42 47.42)( Vi )
=
Vo =
( R X L ) jX C (5.42 47.42) j 19.65
Vo = 0.337 124.24 Vi
V
and Aυ = o = 0.337 (acceptable since relatively close to cut frequency for tweeter)
Vi
CHAPTER 21
309
c.
Mid-range speaker − 3 kHz:
Z = 7.41 22.15
Z = 8.24 33.58
Z = 7.816 37.79
ZVi
(7.816 37.79)Vi
=
= 1.11 8.83 Vi
Z jX C
7.816 37.79 j1.36
(7.41 22.15)Vi
ZV1
=
Vo =
= 0.998 46.9 Vi
Z + jX L 7.41 22.15 j 7.35
V
Aυ = o = 0.998 (excellent)
Vi
V1 =
and
310
CHAPTER 21
Chapter 22
1.
a.
2
(40 mH) 2
= 50 mH
M = k L p Ls L s = M 2
(50 mH)(0.8) 2
L pk
b.
ep = N p
es = kNs
c.
ep = L p
es = M
2.
a.
d p
dt
d p
dt
di p
dt
di p
dt
= (20)(0.08 Wb/s) = 1.6 V
= (0.8)(80 t)(0.08 Wb/s) = 5.12 V
= (40 mH)(0.3 103 A/s) = 12 V
= (80 mH)(0.03 103 A/s) = 24 V
k=1
2
b.
(a)
2
( 40 mH )
= 32 mH
Ls = M 2 =
(50 mH)(1) 2
L pk
(b)
ep = 1.6 V, es = kNs
(c)
ep = 15 V, es = 12 V
d p
= (1)(80 t)(0.08 Wb/s) = 6.4 V
dt
k = 0.2
2
3.
(a)
2
(40 mH )
Ls = M 2 =
= 0.8 H
(50 mH)(0.2) 2
L pk
(b)
ep = 1.6 V, es = kNs
(c)
ep = 15 V, es = 12 V
d p
dt
= (0.2)(80 t)(0.08 Wb/s) = 1.28 V
a.
2
( 40 mH ) 2
Ls = M 2 =
= 355.56 mH
(50 mH)(0.3) 2
L pk
b.
ep = N p
es = kNs
c.
d p
dt
d p
dt
= (300 t)(0.08 Wb/s) = 24 V
= (0.9)(25 t)(0.08 Wb/s) = 1.8 V
ep and es the same as problem 1: ep = 15 V, es = 12 V
CHAPTER 22
311
4.
5.
Ns
120 t
Ep =
(40 V) = 240 V
Np
20 t
a.
Es =
b.
Φmax =
a.
Es =
b.
Φm(max) =
6.
Ep =
7.
f=
8.
a.
40 V
Ep
= 7.51 mWb
=
4.4 fN p 4.44(60 Hz)(20 t)
30 t
Ns
(40 V) = 5 V
E p=
240 t
Np
40 V
Ep
=
= 625.63 μWb
4.44 fN p (4.44)(60 Hz)(240 t)
60 t
Np
Es =
(240 V) = 20 V
720 t
Ns
40 V
Ep
= 120 Hz
=
(4.44) N p m (max) (4.44)(20 t)(3.75 mWb)
1
IL = aIp = (2 A) = 0.4 A
5
2
VL = ILZL = A (2 ) = 0.8 V
5
2
b.
9.
10.
11.
Zp =
1
Zin = a2ZL = 2 = 0.08
5
Vg
Ip
=
120 V
= 30
4A
1
Vg = aVL = (600 V) = 150 V
4
V g 150 V
Ip =
=
= 37.5 A
4
Zi
IL = Is =
VL 240 V
= 12 A
=
Z L 20
I s = a = N p 12 A = N p
0.05 A 50
Ip
Ns
50(12)
Np =
= 12,000 turns
0.05
312
CHAPTER 22
12.
a.
a=
1
N p 400 t
=
=
1200
t
3
Ns
2
1
Zi = a ZL = [12 + j12 ] = 1.333 + j1.333 = 1.885 45
3
Ip = Vg/Zi = 100 V/1.885 Ω = 53.05 A
2
13.
IL = aIp =
a.
Zp = a2ZL a =
Zp =
b.
Zp
ZL
10 V
Vp
=
= 36
I p 20 V/ 72
36
=3
4
a=
1
1
1
Vs Ns 1
=
= V s = V p = (10 V) = 3 V
3
3
3
Vp Np 3
P=
14.
1
(53.05 A) = 17.68 A, VL = ILZL = (17.68 A)(16.97 Ω) = 300 V
3
b.
Vs2 (3.33 V ) 2
= 2.78 W
=
Zs
4
a.
Re = Rp + a2Rs = 4 + (4)2 1 = 20
b.
Xe = Xp + a2Xs = 12 + (4)2 2 = 44
c.
Vg
d.
Ip =
e.
aVL =
Zp
=
120 V 0
120 V 0
=
= 0.554 A 11.73
20 + 192 + j 44 212 + j 44
2
or
f.
g.
VL =
CHAPTER 22
a R LV g
= Ipa2RL
2
( R e a R L) j X e
VL = aIpRL0 = (4)(0.554 A 11.73)(20 0) = 26.59 V 11.73
1
Ns
Vg = (120 V) = 30 V
4
Np
313
15.
4t
=4
Ns 1t
Re = Rp + a2Rs = 4 + (4)2 1 = 20
Xe = Xp + a2Xs = 12 + (4)2 2 = 44
Zp = Z Re + Z X e + a 2 Z X L = 20 + j44 + j(4)2 20
= 20 + j44 + j320 = 20 + j364 = 364.55 86.86
Np
a.
a=
b.
Ip =
c.
VRe = (Iθ)(Re0) = (329.17 mA 86.86)(20 0)
Vg
Zp
=
=
120 V 0
= 329.17 mA 86.86
364.55 86.86
= 6.58 V 86.86
VX e = (Iθ)(Xe90) = (329.17 mA 86.86)(44 90)
= 14.48 V 3.14
VX L = I(a2 Z X L ) = (329.17 mA 86.86)(320 Ω 90)
= 105.33 V 3.14
16.
a.
a = Np/Ns = 4 t/1 t = 4, Re = Rp + a2Rs = 4 + (4)2 1 = 20
Xe = Xp + a2Xs = 12 + (4)2 2 = 44
Zp = Re + jXe ja2XC = 20 + j44 j(4)2 20
= 20 + j44 j320 = 20 j276 = 276.72 Ω 85.86
b.
Ip =
c.
V Re = (Ipθ)(Re0) = (0.43 A 85.86)(20 0) = 8.6 V 85.86
V X e = (Ipθ)(Xe90) = (0.43 A 85.86)(44 90) = 18.92 V 175.86
Vg
Zp
=
120 V 0
= 0.43 A 85.86
276.72 85.86
2
V X C = (Ipθ)(a XC90) = (0.43 A 85.86)(320 90) = 137.60 V 4.14
17.
18.
Coil 1:
L1 M12
Coil 2:
L2 M12
LT = L1 + L2 2M12 = 4 H + 7 H 2(1 H) = 9 H
19.
L T ( ) L1 L2 2M 12
M12 = k L1 L2 = (0.8) (200 mH)(600 mH) = 277 mH
LT (+) = 200 mH + 600 mH + 2(277 mH) = 1.35 H
314
CHAPTER 22
20.
M23 = k L2 L3 1 (1 H)(4 H) = 2 H
L1 + M12 M13 = 2 H + 0.2 H 0.1 H = 2.1 H
L2 + M12 M23 = 1 H + 0.2 H 2 H = 0.8 H
L3 M23 M13 = 4 H 2 H 0.1 H = 1.9 H
LT = 2.1 H 0.8 H + 1.9 H = 3.2 H
Coil 1:
Coil 2:
Coil 3:
21.
E1 I1[ Z R1 + Z L1 ] I2[Zm] = 0
I2[ Z L2 + Z RL ] + I1[Zm] = 0
──────────────────────
I1( Z R1 + Z L1 ) + I2(Zm) = E1
I1(Zm) + I2( Z L2 + Z RL ) = 0
───────────────────────
22.
Zi = Zp +
Xm = ωM 90
( M ) 2
( M ) 2
= Rp + j X Lp +
Zs + ZL
Rs + jX Ls + RL
Rp = 2 , X L p = ωLp = (103 rad/s)(8 H) = 8 k
Rs = 1 , X Ls = ωLs = (103 rad/s)(2 H) = 2 k
M = k L p L s = 0.05 (8 H)(2 H) = 0.2 H
Zi = 2 + j8 k +
(103 rad/s 0.2 H ) 2
1 + j 2 k + 20
4 104
21 j 2 103
= 2 + j8 k + 0.21 j19.99 = 2.21 + j7980
Zi = 7980 89.98
= 2 + j8 k +
23.
Np
Vp
2400 V
= 20
120 V
a.
a=
b.
10,000 VA = VsIs Is =
c.
Ip =
d.
a=
Is =
CHAPTER 22
Ns
=
Vs
=
10,000 VA 10,000 VA
= 83.33 A
=
120 V
Vs
10,000 VA 10,000 VA
=
= 4.17 A
2400 V
Vp
Vp
Vs
=
120 V
1
= 0.05 =
2400 V
20
10,000 VA
= 4.17 A, Ip = 83.33 A
2400 V
315
24.
Is = I1 = 2 A, Ep = VL = 40 V
Es = Vs VL = 200 V 40 V = 160 V
200 V
(2 A) = 10 A
VgI1 = VLIL IL = Vg/VL I1 =
40 V
Ip + I1 = IL Ip = IL I1 = 10 A 2A = 8 A
25.
a.
Es =
Ns
Ep
Np
25 t
(100 V 0) = 25 V 0 = VL
100 t
E
25 V 0
= 5 A 0 = IL
Is = s =
Z L 5 0
=
2
26.
b.
N
100 t
2
Zi = a ZL = p Z L
5 0 = (4) 5 0 = 80 0
25 t
Ns
c.
1
1
Z1/ 2 = Zi = (80 0) = 20 0
4
4
a.
b.
2
2
15 t
E2 = N 2 E1 =
(60 V 0) = 10 V 0
90 t
N1
45 t
E3 = N 3 E1 =
(60 V 0) = 30 V 0
90 t
N1
10 V 0
I2 = E 2 =
= 1.25 A 0
Z 2 8 0
30 V 0
I3 = E 3 =
= 6 A 0
Z3 5 0
1
R1
=
1
1
2
( N1 / N 2 ) R2 ( N1 / N 3 ) 2R3
1
1
2
(90 t /15 t ) 8 (90 t / 45 t ) 2 5
1
1
1
= 0.05347 S
R1 288 20
R1 = 18.70
=
27.
a.
N2
40 t
E1 =
(120 V 60) = 40 V 60
N1
120 t
E
40 V 60
= 3.33 A 60
I2 = 2 =
Z 2 12 0
E2 =
N3
30 t
E1 =
(120 V 60) = 30 V 60
N1
120 t
E
30 V 60
I3 = 3 =
= 3 A 60
Z3 10 0
E3 =
316
CHAPTER 22
b.
1
R1
=
1
1
2
( N1 / N 2 ) R2 ( N1 / N 3 ) 2R3
1
1
2
(120 t / 40 t ) 12 (120 t / 30 t ) 210
1
1
1
=
= 0.0155 S
108
160
R1
1
= 64.52
R1 =
0.0155 S
=
28.
ZM = Z M12 = ωM12 90
E I1Z1 I1 Z L1 I1(Zm) I2(+Zm) I1 Z L2 + I2 Z L2 I1(Zm) = 0
E I1(Z1 + Z L1 Zm + Z L2 Zm) I2(Zm Z L2 ) = 0
or
I1(Z1 + Z L1 + Z L2 2 Zm) + I2(Zm Z L2 ) = E
──────────────────────────────────────────────
I2Z2 Z L2 (I2 I1) I1(+Zm) = 0
or
I1(Zm Z L2 ) + I2(Z2 + Z L2 ) = 0
──────────────────────────
E1 I1Z1 I1 Z L1 I2( Z M12 ) I3(+ Z M13 ) = 0
29.
or
E1 I1[Z1 + Z L1 ] + I2 Z M12 I3 Z M13 = 0
────────────────────────────────
I2(Z2 + Z3 + Z L2 ) + I3Z2 I1( Z M12 ) = 0
or
I2(Z2 + Z3 + Z L2 ) + I3Z2 + I1 Z M12 = 0
────────────────────────────────
I3(Z2 + Z4 + Z L3 ) + I2Z2 I1(+ Z M13 ) = 0
or
I3(Z2 + Z4 + Z L3 ) + I2Z2 I1 Z M13 = 0
─────────────────────────────
Z M12 I2 +
[Z1 + Z L1 ]I1
Z M12 I1 [Z2 + Z3 + Z L2 ]I2 +
Z M13 I3 = E1
Z2I3 = 0
Z M13 I1
Z2I2 + [Z2 + Z4 + Z L3 ]I3 = 0
────────────────────────────────────────
CHAPTER 22
317
Chapter 23
1.
2.
a.
E = EL/ 3 = 208 V/1.732 = 120.1 V
b.
V = E = 120.1 V
c.
I =
d.
IL = I = 12.01 A
a.
E = EL/ 3 = 208 V/1.732 = 120.1 V
b.
V = E = 120.1 V
c.
Z = 12 j16 Ω = 20 53.13
d.
IL = I = 6 A
b.
V = 120.1 V
I =
3.
4.
V 120.1 V
6A
=
20
Z
a.
E = 120.1 V
c.
Z = (10 0 (10 90) = 7.071 45
120.1 V
V
I = =
= 16.98 A
Z 7.071
d.
IL = 16.98 A
a.
θ2 = 120, θ3 = 120
b.
Van = 120 V 0, Vbn = 120 V 120, Vcn = 120 V 120
c.
5.
V 120.1 V
= 12.01 A
=
10
R
120 V 0
Ian = V an =
= 6 A 0
Z an 20 0
120 V 120
Ibn = V bn =
= 6 A 120
20 0
Z bn
120 V 120
Icn = V cn =
= 6 A 120
20 0
Z cn
d.
IL = I = 6A
a.
θ2 = 120, θ3 = +120
b.
Van = 120 V 0, Vbn = 120 V 120, Vcn = 120 V 120
c.
Z = 9 + j12 = 15 53.13
e.
VL =
3 V =
3 (120 V) = 207.8 V
120 V 0
120 V 120
= 8 A 53.13, Ibn =
= 8 A 173.13
15 53.13
15 53.13
120 V 120
= 8 A 66.87
Icn =
15 53.13
Ian =
318
CHAPTER 23
e.
6.
a, b.
c.
IL = I = 8 A
f.
EL =
3 E = (1.732)(120 V) = 207.85 V
The same as problem 4.
Z = 6 0 8 90 = 4.8 36.87
120 V 0
= 25 A 36.87
Ian = V an =
Z an 4.8 36.87
120 V 120
Ibn = V bn =
= 25 A 83.13
Z bn 4.8 36.87
120 V 120
Icn = V cn =
= 25 A 156.87
Z cn 4.8 36.87
d.
7.
IL = I = 25 A
e.
VL
VL =
3 V =
3 (120 V) = 207.84 V
220 V
= 127.0 V
3 1.732
Z = 10 j10 = 14.42 45
V = Van = Vbn = Vcn =
=
127 V
V
=
= 8.98 A
Z 14.142
IL = IAa = IBb = ICc = I = 8.98 A
I = Ian = Ibn = Icn =
8.
Z = 12 + j16 = 20 53.13
V 50 V
=
= 2.5 A
Z 20
ZT = 13 + j16 = 20.62 50.91
I =
V = I Z T = (2.5 A)(20.62 ) = 51.55 V
VL =
9.
a.
3 V =
3 (51.55 V) = 89.29 V
22 kV
30 = 12.7 kV 30
3
22 kV
EBN =
150 = 12.7 kV 150
3
22 kV
ECN =
90 = 12.7 kV 90
3
EAN =
CHAPTER 23
319
b, c. IAa = Ian =
E AN
12.7 kV 30
=
(30 + j 40 ) + (0.4 k + j1 k )
Z AN
12.7 kV 30
12.7 kV 30
=
430 + j1040 1125.39 67.54
= 11.29 A 97.54
12.7 kV 150
= 11.29 A 217.54
=
1125.39 67.54
12.7 kV 90
=
= 11.29 A 22.46
1125.39 67.54
=
IBb = Ibn = E BN
Z BN
E CN
ICc = Icn =
Z CN
10.
11.
12.
13.
320
d.
Van = IanZan = (11.29 A 97.54)(400 + j1000)
= (11.29 A 97.54)(1077.03 68.2)
= 12.16 kV 29.34
Vbn = IbnZbn = (11.29 A 217.54)(1077.03 68.2)
= 12.16 kV 149.34
Vcn = IcnZcn = (11.29 A 22.46)(1077.03 68.2)
= 12.16 kV 90.66
a.
E = EL/ 3 = 208 V/1.732 = 120.1 V
c.
I =
a.
E = EL/ 3 = 208 V/1.732 = 120.1 V
c.
Z = 6.8 + j14 = 15.564 64.09
208 V
V
= 13.36 A
I = =
Z 15.564
d.
IL = 3 I = (1.732)(13.36 A) = 23.14 A
V 208 V
= 10.4 A
=
Z 20
b.
V = EL = 208 V
d.
IL = 3 I = (1.732)(10.4 A) = 18 A
b.
V = EL = 208 V
b.
V = 208 V
Z = 18 0 18 90 = 12.728 45
a.
E = VL/ 3 = 208 V/ 3 = 120.09 V
c.
I =
d.
IL = 3 I = (1.732)(16.34 A) = 28.30 A
a.
θ2 = 120, θ3 = +120
b.
Vab = 208 V 0, Vbc = 208 V 120, Vca = 208 V 120
208 V
V
=
= 16.34 A
Z 12.728
CHAPTER 23
c.
d.
14.
208 V 0
Iab = V ab =
= 9.46 A 0
Z ab 22 0
208 V 120
Ibc = V bc =
= 9.46 A 120
22 0
Z bc
208 V 120
= 9.46 A 120
Ica = V ca =
22 0
Z ca
e.
IL = 3 I = (1.732)(9.46 A) = 16.38 A
f.
E = EL/ 3 = 208 V/1.732 = 120.1 V
a.
θ2 = 120, θ3 = +120
b.
Vab = 208 V 0, Vbc = 208 V 120, Vca = 208 V 120
c.
d.
Z = 100 j100 = 141.42 45
208 V 0
Iab = V ab =
= 1.47 A 45
141.42
45
Z ab
208 V 120
Ibc = V bc =
= 1.47 A 75
Z bc 141.42 45
208 V 120
Ica = V ca =
= 1.47 A 165
Z ca 141.42 45
e.
IL = 3 I = (1.732)(1.471 A) = 2.55 A
f.
E = EL/ 3 = 208 V/1.732 = 120.1 V
15. a, b.
The same as problem 13.
c.
d.
Z = 3 0 4 90 = 2.4 36.87
208 V 0
Iab = V ab =
= 86.67 A 36.87
Z ab 2.4 36.87
208 V 120
Ibc = V bc =
= 86.67 A 156.87
Z bc 2.4 36.87
208 V 120
Ica = V ca =
= 86.67 A 83.13
Z ca 2.4 36.87
CHAPTER 23
321
e.
IL =
3 I = (1.732)(86.67 A) = 150.11 A
16.
Vab = Vbc = Vca = 220 V
Z = 10 + j10 = 14.142 45
220 V
V
= 15.56 A
Iab = Ibc = Ica = =
14.142
Z
17.
a.
f.
E = 120.1 V
16 kV 0
16 kV 0
=
Iab = V ab =
Z ab 300 + j1000 1044.03 73.30
Iab = 15.33 A 73.30
16 kV 120
Ibc = V bc =
= 15.33 A 193.30
Z bc 1044.03 73.30
16 kV 120
Ica = V ca =
= 15.33 A 46.7
Z ca 1044.03 73.30
b.
IAa Iab + Ica = 0
IAa = Iab Ica = 15.33 A 73.30 15.33 A 46.7
= (4.41 A j14.68 A) (10.51 A + j11.16 A)
= 4.41 A 10.51 A j(14.68 A + 11.16 A)
= 6.11 A j25.84 A = 26.55 A 103.30
IBb + Iab = Ibc
IBb = Ibc Iab = 15.33 A 193.30 15.33 A 73.30
= 26.55 A 136.70
ICc + Ibc = Ica
ICc = Ica Ibc = 15.33 A 46.7 15.33 A 193.30
= 26.55 A 16.70
c.
EAB = IAa(10 + j20 ) + Vab IBb(22.361 63.43)
= (26.55 A 103.30)(22.361 63.43) + 16 kV 0
(26.55 A 136.70)(22.361 63.43)
= (455.65 V j380.58 V) + 16,000 V (557.42 V j204.32 V)
= 17.01 kV j176.26 V
= 17.01 kV 0.59
EBC = IBb(22.361 63.43) + Vbc ICc(22.361 63.53)
= (26.55 A 136.70)(22.361 63.53) + 16 kV 120
(26.55 A 16.70)(22.361 63.53)
= 17.01 kV 120.59
ECA = ICc(22.361 63.43) + Vca IAa(22.361 63.43)
= 17.01 kV 119.41
322
CHAPTER 23
18.
19.
a.
E = EL = 208 V
c.
I =
a.
E = EL = 208 V
c.
I =
20. a, b.
c.
V 120.09 V
=
= 7.08 A
Z 16.971
208 V
V = E L =
= 120.1 V
3 1.732
d.
IL = I 4 A
b.
V = EL 3 = 120.09 V
d.
IL = I = 7.08 A
The same as problem 18.
Z = 15 0 20 90 = 12 36.87
I =
d.
V 120.1 V
= 4.00 A
=
30
Z
b.
V 120.1 V
=
10 A
12
Z
IL = I 10 A
120 V 120 V
= 69.28 V
=
1.732
3
69.28 V
Ian = Ibn = Icn =
= 2.89 A
24
IAa = IBb = ICc = 2.89 A
21.
Van = Vbn = Vcn =
22.
Van = Vbn = Vcn =
120 V
= 69.28 V
3
Z = 10 + j20 = 22.36 63.43
Ian = Ibn = Icn =
V
Z
=
69.28 V
= 3.10 A
22.36
IAa = IBb = ICc = I = 3.10 A
23.
Van = Vbn = Vcn = 69.28 V
Z = 20 0 15 90 = 12 53.13
69.28 V
= 5.77 A
12
IAa = IBb = ICc = 5.77 A
Ian = Ibn = Icn =
24.
a.
E = EL = 440 V
c.
I =
CHAPTER 23
V 440 V
=2A
=
Z 220
b.
V = EL = E = 440 V
d.
IL = 3 I = (1.732)(2 A) = 3.46 A
323
25.
a.
E = EL = 440 V
c.
Z = 12 j9 = 15 36.87
26. a, b.
c.
The same as problem 24.
Z = 22 0 22 90 = 15.56 45
440 V
V
= 28.28 A
=
Z 15.56
3 I = (1.732)(28.28 A) = 48.98 A
d.
IL =
a.
θ2 = 120, θ3 = +120
b.
Vab = 100 V 0, Vbc = 100 V 120, Vca = 100 V 120
c.
d.
28.
3 I = (1.732)(29.33 A) = 50.8 A
IL =
I =
27.
V = EL = 440 V
V 440 V
= 29.33 A
=
Z 15
I =
d.
b.
100 V 0
= 5 A 0
Iab = V ab =
Z ab 20 0
100 V 120
Ibc = V bc =
= 5 A 120
20 0
Z bc
100 V 120
Ica = V ca =
= 5 A 120
20 0
Z ca
3 (5 A) = 8.66 A
e.
IAa = IBb = ICc =
a.
θ2 = 120, θ3 = +120
b.
Vab = 100 V 0, Vbc = 100 V 120, Vca = 100 V 120
c.
d.
Z = 12 + j16 = 20 53.13
100 V 0
V ab
=
= 5 A 53.13
Z ab 20 53.13
100 V 120
Ibc = V bc =
= 5 A 173.13
Z bc 20 53.13
Iab =
324
CHAPTER 23
100 V 120
Ica = V ca =
= 5 A 66.87
Z ca 20 53.13
29.
3 I = (1.732)(5 A) = 8.66 A
e.
IAa = IBb = ICc =
a.
θ2 = 120, θ3 = 120
b.
Vab = 100 V 0, Vbc = 100 V 120, Vca = 100 V 120
c.
d.
Z = 20 0 20 90 = 14.14 45
100 V 0
= 7.07 A 45
14.14 45
100 V 120
Ibc =
= 7.07 A 75
14.14 45
100 V 120
= 7.07 A 165
Ica =
14.14 45
Iab =
e.
30.
IAa = IBb = ICc =
3 (7.07 A) = 12.25 A
PT = 3I2 R = 3(6 A)2 12 = 1296 W
QT = 3I2 X = 3(6 A)2 16 = 1728 VAR(C)
ST =
2
2
PT QT = 2160 VA
1296 W
= 0.6 (leading)
Fp = PT =
2160
VA
ST
31.
V = 120 V, I = 120 V/20 = 6 A
PT = 3I2 R = 3(6 A)2 20 = 2160 W
QT = 0 VAR
ST = PT = 2160 VA
2160 W
Fp = PT =
=1
S T 2160 VA
32.
PT = 3I2 R = 3(8.98 A)2 10 = 2419.21 W
QT = 3I2 X = 3(8.98 A)2 10 = 2419.21 VAR(C)
ST =
Fp =
PT2 Q T2 = 3421.28 VA
PT
2419.21 W
= 0.7071 (leading)
=
ST 3421.28 VA
CHAPTER 23
325
33.
V = 208 V
V 2
(208 V ) 2
PT = 3 = 3
= 7210.67 W
18
R
V2
(208 V ) 2
QT = 3 = 3
= 7210.67 VAR(C)
18
X
2
2
PT QT = 10,197.42 VA
ST =
7210.67 W
= 0.707 (leading)
Fp = PT =
10,197.42
VA
ST
34.
PT = 3I2 R = 3(1.471 A)2 100 = 649.15 W
QT = 3I2 X = 3(1.471 A)2 100 = 649.15 VAR(C)
PT2 QT2 = 918.04 VA
ST =
Fp =
35.
PT
649.15 W
= 0.7071 (leading)
=
ST 918.04 VA
PT = 3I2 R = 3(15.56 A)2 10 = 7.26 kW
QT = 3I2 X = 3(15.56 A)2 10 = 7.26 kVAR
PT2 Q T2 = 10.27 kVA
ST =
Fp =
PT
7.263 kW
= 0.7071 (lagging)
=
ST 10.272 kVA
2
36.
PT = 3
2
V 3(120.1 V )
=
= 2884.80 W
15
R
2
QT = 3
2
V 3(120.1 V )
=
= 2163.60 VAR(C)
20
X
2
2
PT QT = 3605.97 VA
P
2884.80 W
Fp = T =
= 0.8 (leading)
ST 3605.97 VA
ST =
37.
Z = 10 + j20 = 22.36 63.43
V L 120 V
=
= 69.28 V
3 1.732
69.28 V
V
= 3.098 A
I = =
Z 22.36
V =
PT = 3I2 R = 3(3.098 A)2 10 = 287.93 W
326
CHAPTER 23
QT = 3I2 X = 3(3.098 A)2 20 Ω = 575.86 VAR
PT2 QT2 = 643.83 VA
ST =
Fp =
PT
287.93 W
= 0.447 (lagging)
=
ST 643.83 VA
2
38.
ST =
Fp =
39.
2
V 3(440 V )
=
= 26.4 kW
22
R
QT = PT = 26.4 kVAR(L)
PT = 3
PT2 QT2 = 37.34 kVA
PT
26.4 kW
= 0.707 (lagging)
=
ST 37.34 kVA
Z = 12 + j16 = 20 53.13
I =
V 100 V
=5A
=
Z 20
PT = 3I2 R = 3(5 A)2 12 = 900 W
QT = 3I2 X = 3(5 A)2 16 = 1200 VAR(L)
2
2
PT QT = 1500 VA
P
900 W
Fp = T =
= 0.6 (lagging)
ST 1500 VA
ST =
40.
PT = 3 ELIL cos θ
4800 W = (1.732)(200 V)IL (0.8)
IL = 17.32 A
I
17.32 A
I = L =
= 10 A
1.732
3
θ = cos1 0.8 = 36.87
200 V 0
V
Z = =
= 20 36.87 = 16 + j12
I 10 A 36.87
41.
PT =
3 ELIL cos θ
1200 W = 3 (208 V)IL(0.6) IL = 5.55 A
V
208 V
V = L =
= 120.1 V
3 1.732
θ = cos1 0.6 = 53.13 (leading)
120.1 V 0
V
Z = =
j 17.31
= 21.64 53.13 = 12.98
I 5.55 A 53.13
R
XC
CHAPTER 23
327
42.
Δ:
Z = 15 + j20 = 25 53.13
V
I =
Z
=
125 V
=5A
25
PT = 3I2 R = 3(5 A)2 15 = 1125 W
QT = 3I2 X = 3(5 A)2 20 = 1500 VAR(L)
Y:
V = VL/ 3 = 125 V/1.732 = 72.17 V
Z = 3 j4 = 5 53.13
I =
V 72.17 V
= 14.43 A
=
5
Z
PT = 3I2 R = 3(14.43 A)2 3 = 1874.02 W
QT = 3I2 X = 3(14.43 A)2 4 = 2498.7 VAR
PT = 1125 W + 1874.02 W = 2999.02 W
QT = 1500 VAR(L) 2498.7 VAR(C) = 998.7 VAR(C)
ST =
Fp =
43.
a.
c.
d.
e.
PT2 QT2 = 3161 VA
PT 2999.02 W
= 0.949 (leading)
=
3161 VA
ST
E =
16 kV
= 9,237.6 V
3
b.
IL = I = 80 A
1200 kW
= 400 kW
3
P4Ω = (80 A)24 = 25.6 kW
PT = 3P = 3(25.6 kW + 400 kW) = 1276.8 kW
P L =
Fp =
PT
, ST =
ST
Fp =
1, 276.8 kW
= 0.576 lagging
2,217.025 kVA
3 VLIL =
3 (16 kV)(80 A) = 2,217.025 kVA
θL = cos1 0.576 = 54.83 (lagging)
E AN0 80A 54.83°
IAa =
Z T 54.83
given
for entire load
328
CHAPTER 23
44.
f.
Van = EAN IAa(4 + j20 )
= 9237.6 V 0 (80 A 54.83)(20.396 78.69)
= 9237.6 V 0 1631.68 V 23.86
= 9237.6 V (1492.22 V + j660 V)
= 7745.38 V j660 V
= 7773.45 V 4.87
g.
Z =
h.
Fp(entire system) = 0.576 (lagging)
Fp(load) = 0.643 (lagging)
V an 7773.45 V 4.87
=
= 97.168 49.95
80 A 54.83
I Aa
= 62.52
+ j 74.38
R
XC
i.
1276.8 kW 3(25.6 kW)
η = P o = P i P lost =
= 0.9398 93.98%
1276.8 kW
Pi
Pi
a.
b.
V =
220 V
= 127.02 V, Z = 10 j10 = 14.14 45
3
127.02 V
V
I = =
= 8.98 A
Z 14.14
PT = 3I2 R = 3(8.98 A)2 10 = 2419.2 W
Each wattmeter:
2419.2 W
= 806.4 W
3
45.
b.
PT = 5899.64 W, Pmeter = 1966.55 W
46.
a.
b.
PT = P + Ph = 85 W + 200 W = 285 W
c.
0.2 P = 0.5
Ph
100 W
Ph = P =
= 200 W
0.5
0.5
PT = Ph P = 200 W 100 W = 100 W
CHAPTER 23
329
48.
a.
208 V 0
Iab = E AB =
= 20.8 A 0
R0 10 0
208 V 120 208 V 120
E BC
= 14.708 A 165
Ibc =
=
R jX L
10 j10
14.142 45
208 V 120
208 V 120
E CA
Ica =
= 14.708 A 165
=
R jX C 10 j10 14.142 45
b.
IAa + Ica Iab = 0
IAa = Iab Ica
= 20.8 A 0 14.708 A 165
= 20.8 A (14.207A + j3.807 A)
= 35.007 A j3.807 A
= 35.213 A 6.207
IBb + Iab Ibc = 0
IBb = Ibc Iab
= 14.708 A 165 20.8 A 0
= (14.207 A j3.807 A) 20.8 A
= 35.007 A j3.807 A
= 35.213 A 173.79
ICc + Ibc Ica = 0
ICc = Ica Ibc
= 14.708 A 165 14.708 A 165
= (14.207 A + j3.807 A) (14.207 A j3.807 A)
= 7.614 A 90
c.
P1 = VacIAa cos IVAaca Vca = Vca θ 180 = 208 V 120 180
= 208 V 60
IAa = 35.213 A 6.207
P1 = (208 V)(35.213 A) cos 53.793
= 4.326 kW
P2 = VbcIBb cos IVBbbc Vbc = 208 V 120
IBb = 35.213 A 173.79
P2 = (208 V)(35.213 A) cos 53.79
= 4.327 kW
d.
330
PT = P1 + P2 = 4.326 kW + 4.327 kW = 8.653 kW
CHAPTER 23
49.
a.
b.
c.
V = E = E L = 120.09 V
3
120.09 V
Ian = V an =
= 8.49 A
Z an 14.142
120.09 V
V
= 7.08 A
Ibn = bn =
Z bn 16.971
120.09 V
Icn = V cn =
= 42.47 A
Z cn 2.828
2
2
10 + I bn
12 + I cn2 2
PT = I an
= (8.49 A)2 10 + (7.08 A)2 12 + (42.47 A)2 2
= 720.80 W + 601.52 W + 3.61 kW
= 4.93 kW
QT = PT = 4.93 kVAR(L)
ST =
Fp =
50.
PT2 QT2 = 6.97 kVA
PT
= 0.707 (lagging)
ST
d.
Ean = 120.09 V30, Ebn = 120.09 V150, Ecn = 120.09 V90
120.09 V 30 120.09 V 30
= 8.49 A 75
=
Ian = E an =
10 + j10
14.142 45
Z an
120.09 V 150 120.09 V 150
Ibn = Ebn =
= 7.08 A 195
=
12 + j12
16.971 45
Z bn
120.09 V 90 120.09 V 90
Icn = Ecn =
=
= 42.47 A 45
2 + j2
2.828 45
Z cn
e.
IN = Ian + Ibn + Icn
= 8.49 A 75 + 7.08 A 195 + 42.47 A45
= (2.02 A j8.20 A) + (6.84 A + j1.83 A) + (30.30 A + j30.30 A)
= 25.66 A j23.93 A
= 35.09 A 43.00
Z1 = 12 j16 = 20 53.13, Z2 = 3 + j4 = 5 53.13
Z3 = 20 0
EAB = 200 V0, EBC = 200 V 120, ECA = 200 V 120
ZΔ = Z1Z2 + Z1Z3 + Z2Z3
= (20 53.13)(5 53.13) + (20 53.13)(20 0)
+ (5 53.13)(20 0)
= 100 0 + 400 53.13 + 100 53.13
= 100 + (240 j320 ) + (60 + j80 )
= 400 j240
= 466.48 30.96
CHAPTER 23
331
Ian =
E AB Z3 ECA Z 2 (200 V 0)(20 0) (200 V 120)(5 53.13)
=
Z
Z
4000 A 0 1000 A 173.13
= 10.71 A 29.59
466.48 30.96
E Z E AB Z3 (200 V 120)(20 53.13) (200 V 0)(20 0)
Ibn = BC 1
=
Z
Z
=
4000 A 173.13 4000 A 0
= 17.12 A 145.61
466.48 30.96
E Z E BC Z1 (200 V 120)(5 53.13) (200 V 120)(20 53.13)
Icn = CA 2
=
Z
Z
=
1000 A 173.13 4000 A 173.13
= 6.51 A 42.32
466.48 30.96
2
2
PT = I an
12 + I bn
4 + I cn2 20
= 1376.45 W + 1172.38 W + 847.60 W = 3396.43 W
2
2
QT = I an
16 + I bn
3 = 1835.27 VAR(C) + 879.28 VAR(L) = 955.99 VAR(C)
=
ST =
Fp =
332
PT2 QT2 = 3508.40 VA
PT
3396.43 W
= 0.968 (leading)
=
ST 3508.40 VA
CHAPTER 23
Chapter 24
1.
a.
positive-going
d.
Amplitude = 8 V 2 V = 6 V
e.
f.
g.
2.
Vb = 2 V
tp = 0.2 ms
V1 V 2
100%
V
8V + 7.5 V
= 7.75 V
V=
2
8 V 7.5 V
% tilt =
100% = 6.5%
7.75 V
1
1
1
prf = =
= 625 kHz
T (2.0 ms 0.4 ms) 1.6 ms
tp
T
100%
0.2 ms
100% = 12.5%
1.6 ms
negative-going
d.
8 mV ( from base line level)
b.
+7 mV
c.
3 μs
8 mV 7 mV 15 mV
=
= 7.5 mV
2
2
8 mV (7 mV)
% Tilt = V 1 V 2 100% =
100%
V
7.5 mV
1 mV
=
100% = 13.3%
7.5 mV
V=
f.
T = 15 μs 7 μs = 8 μs
1
1
= 125 kHz
prf = =
T 8 s
g.
Duty cycle =
a.
positive-going
d.
Amplitude = (30 10)mV = 20 mV
e.
c.
% tilt =
a.
e.
3.
b.
3 s
tp
100% =
100% = 37.5%
T
8 s
b.
Vb = 10 mV
c.
8
tp = 4 ms = 3.2 ms
10
V1 V 2
100%
V
30 mV + 28 mV
= 29 mV
V=
2
30 mV 28 mV
% tilt =
100% 6.9%
29 mV
% tilt =
CHAPTER 24
333
4.
tr (0.2 div.)(2 ms/div.) = 0.4 ms
tf (0.4 div.)(2 ms/div.) = 0.8 ms
5.
tilt =
V1 V2
V V
= 0.1 with V = 1 2
V
2
Substituting V into top equation,
V1 V2
0.95 V1
= 0.1 leading to V2 =
or V2 = 0.905(15 mV) = 13.58 Mv
V1 V2
1.05
2
6.
7.
a.
tr = 80% of straight line segment
= 0.8(2 μs) = 1.6 μs
b.
tf = 80% of 4 μs interval
= 0.8(4 μs) = 3.2 μs
c.
At 50% level (10 mV)
tp = (8 1)μs = 7 μs
d.
prf =
a.
T = (4.8 2.4)div. 50 s/div. = 120 μs
c.
8.
334
1
1
=
= 50 kHz
T 20 s
b.
f=
1
1
= 8.33 kHz
T 120 s
Maximum Amplitude: (2.2 div.)(0.2 V/div.) = 0.44 V = 440 mV
Minimum Amplitude: (0.4 div.)(0.2 V/div.) = 0.08 V = 80 mV
T = (3.6 2.0)ms = 1.6 ms
1
1
= 625 Hz
prf = =
T 1.6 ms
tp
0.2 ms
Duty cycle = 100% =
100% = 12.5%
T
1.6 ms
CHAPTER 24
9.
T = (15 7)μs = 8 μs
1
1
= 125 kHz
prf =
T 8 s
tp
(20 15) s
5
100% = 100% = 62.5%
Duty cycle = 100%
T
8 s
8
10.
T = (3.6 div.)(2 ms/div.) = 7.2 ms
1
1
prf = =
= 138.89 Hz
T 7.2 ms
tp
1.6 div.
Duty cycle = 100% =
100% = 44.4%
T
3.6 div.
11.
a.
T = (9 1)μs = 8 μs
c.
prf =
d.
Vav = (Duty cycle)(Peak value) + (1 Duty cycle)(Vb)
tp
2 s
100% = 25%
Duty cycle = 100%
T
8 s
Vav = (0.25)(6 mV) + (1 0.25)(2 mV)
= 1.5 mV 1.5 mV = 0 V
or
(2 s)(6 mV) (2 s)(6 mV)
Vav =
=0V
8s
e.
Veff =
12.
b.
tp = (3 1)μs = 2 μs
1
1
= 125 kHz
T 8 s
(36 106 )(2 s) (4 106 )(6 s)
= 3.46 mV
8 s
Eq. 24.5 cannot be applied due to tilt in the waveform.
(Method of Section 13.6)
Between 2 and 3.6 ms
1
(3.4 ms 2 ms)(2 V) + (3.6 ms 3.4 ms)(7.5 V) + (3.6 ms 3.4 ms)(0.5 V)
2
Vav =
3.6 ms 2 ms
1
(1.4 ms)(2 V) + (0.2 ms)(7.5 V) + (0.2 ms)(0.5 V)
2
=
1.6 ms
2.8 V + 1.5 V + 0.05 V
=
= 2.719 V
1.6
CHAPTER 24
335
13.
Ignoring tilt and using 20 mV level to define tp
tp = (2.8 div. 1.2 div.)(2 ms/div.) = 3.2 ms
T = (at 10 mV level) = (4.6 div. 1 div.)(2 ms/div.) = 7.2 ms
3.2 ms
t
100% = 44.4%
Duty cycle = p 100%
T
7.2 ms
Vav = (Duty cycle)(peak value) + (1 Duty cycle)(Vb)
= (0.444)(30 mV) + (1 0.444)(10 mV)
= 13.320 mV + 5.560 mV
= 18.88 mV
14.
Vav = (Duty cycle)(Peak value) + (1 Duty cycle)(Vb)
tp
Duty cycle =
(decimal form)
T
(8 1) s
= 0.35
=
20 s
Vav = (0.35)(20 mV) + (1 0.35)(0)
= 7 mV + 0
= 7 mV
15.
Using methods of Section 13.8:
A1 = b1h1 = [(0.2 div.)(50 μs/div.)][(2 div.)(0.2 V/div.)] = 4 μsV
A2 = b2h2 = [(0.2 div.)(50 μs/div.)][(2.2 div.)(0.2 V/div.)] = 4.4 µsV
A3 = b3h3 = [(0.2 div.)(50 μs/div.)][(1.4 div.)(0.2 V/div.)] = 2.8 μsV
A4 = b4h4 = [(0.2 div.)(50 μs/div.)][(1 div.)(0.2 V/div.)] = 2.0 μsV
A5 = b5h5 = [(0.2 div.)(50 μs/div.)][(0.4 div.)(0.2 V/div.)] = 0.8 μsV
Vav =
16.
Using the defined polarity of Fig. 24.57 for υC, Vi = 5 V, Vf = +20 V
and τ = RC = (10 k)(0.02 μF) = 0.2 ms
a.
336
(4 4.4 2.8 2.0 0.8) sV
= 117 mV
120 s
υC = Vi + (Vf Vi)(1 et/τ)
= 5 + (20 (5))(1 et/0.2 ms)
= 5 + 25(1 et/0.2 ms)
= 5 + 25 25et/0.2 ms
υC = 20 V 25 Vet/0.2 ms
CHAPTER 24
b.
c.
Ii = 0
iC =
E C 20 V 20 V 25 V e
=
R
10 k
t / 0.2 ms
= 2.5 mAet/0.2 ms
d.
17.
υC = Vi + (Vf Vi)(1 et/RC)
= 8 + (4 8)(1 et/20 ms)
= 8 4(1 et/20 ms)
= 8 4 + 4et/20 ms
= 4 + 4et/20 ms
υC = 4 V(1 + et/20 ms)
18.
Vi = 10 V, Vf = 2 V, τ = RC = (1 k)(1000 μF) = 1 s
υC = Vi + (Vf Vi)(1 et/τ)
= 10 V + (2 V 10 V)(1 et)
= 10 8(1 et)
= 10 8 + 8et
υC = 2 V+ 8 Vet
19.
Vi = 10 V, Ii = 0 A
CHAPTER 24
τ
= RC = (2 k)(10 μF)
= 20 ms
Using the defined direction of iC
(10 V 2 V) t/τ
e
iC =
1k
τ = RC = (1 k)(1000 μF) = 1 s
8 V t
iC =
e
1k
and iC = 8mAet
337
20.
τ
= RC = (5 k)(0.04 μF) = 0.2 ms (throughout)
υC = E(1 et/τ) = 20 V(1 et/0.2 ms)
(Starting at t = 0 for each plot)
a.
T=
1
1
=
= 2 ms
f 500 Hz
T
= 1 ms
2
5τ = 1 ms =
b.
T=
T
2
1
1
=
= 10 ms
f 100 Hz
T
= 5 ms
2
5τ = 1 ms =
c.
T=
1T
5 2
1
1
=
= 0.2 ms
f 5 Hz
T
= 0.1 ms
2
T
5τ = 1 ms = 10
2
21.
The mathematical expression for iC is the same for each frequency!
τ = RC = (5 k)(0.04 μF) = 0.2 ms
20 V t / 0.2 ms
= 4 mAet/0.2 ms
and iC =
e
5 k
a.
T=
1
T
= 2 ms, = 1 ms
500 Hz
2
5τ = 5(0.2 ms) = 1 ms =
338
b.
T=
c.
T=
T
2
1
T
= 10 ms,
= 5 ms
100 Hz
2
1T
5τ = 1 ms =
5 2
1
T
= 0.2 ms,
= 0.1 ms
5000 Hz
2
T
5τ = 1 ms = 10
2
CHAPTER 24
22.
τ
= 0.2 ms as above
1
= 2 ms
T=
500 Hz
T
5τ = 1 ms =
2
T
0 : υC = 20 V(1 et/0.2 ms)
2
T
T: Vi = 20 V, Vf = 20 V
2
υC = Vi + (Vf Vi)(1 et/τ)
= 20 + (20 20)(1 et/0.2 ms)
= 20 40(1 et/0.2 ms)
= 20 40 + 40et/0.2 ms
υC = 20 V+ 40 Vet/0.2 ms
T
23.
3
T : Vi = 20 V, Vf = +20 V
2
υC = Vi + (Vf Vi)(1 et/τ)
= 20 + (20 (20))(1 et/τ)
= 20 + 40(1 et/τ)
= 20 + 40 40et/τ
υC = 20 V 40 Vet/0.2 ms
υC = Vi + (Vf Vi)(1 et/RC)
Vi = 20 V, Vf = 20 V
υC = 20 + (20 20)(1 et/RC)
T
= 20 V (for 0 )
2
For
T
T, υi = 0 V and υC = 20 Vet/τ
2
τ
with
= RC = 0.2 ms
T
T
= 1 ms and 5τ =
2
2
3
T , υi = 20 V
2
υC = 20 V(1 et/τ)
For T
For
3
T 2T, υi = 0 V
2
υC = 20 Vet/τ
CHAPTER 24
339
24.
25.
τ
= RC = 0.2 ms
T
5τ = 1 ms =
2
Vi = 10 V, Vf = +20 V
T
0 :
2
υC = Vi + (Vf Vi)(1 et/τ)
= 10 + (20 (10))(1 et/τ)
= 10 + 30(1 et/τ)
= 10 + 30 30et/τ
υC = +20 V 30 Vet/0.2 ms
Zp:
Zs:
T
T:
2
Vi = 20 V, Vf = 0 V
υC = 20 Vet/0.2 ms
1
1
=
= 5.31 M
2 fC 2 (10 kHz)(3 pF)
(9 M 0)(5.31 M 90)
Zp =
= 4.573 M 59.5
9 M j 5.31 M
XC =
CT = 18 pF + 9 pF = 27 pF
1
1
= 0.589 M
XC =
=
2 fC T 2 (10 kHz)(27 pF)
Zs =
Vscope =
(1 M 0)(0.589 M 90)
= 0.507 M 59.5
1 M j 0.589 M
(0.507 M 59.5)(100 V 0)
ZsVi =
Z s Z p (0.257 M j 0.437 M ) + (2.324 M j 3.939 M )
50.7 106 V 59.5
1
(100 V 0)
= 10 V 0 =
6
10
5.07 10 59.5
= Z p = 59.5
=
Zs
26.
Zp: XC =
1
1
= 3.333 M
=
5
C (10 rad/s)(3 pF)
(9 M 0)(3.333 M )
= 3.126 M 69.68
9 M j 3.333 M
1
1
XC =
= 0.370 M
=
5
C (10 rad/s)(27 pF)
Zp =
Zs:
(1 M 0)(0.370 M 90)
= 0.347 M 69.68
1 M j 0.370 M
Z p = Z s
Zs =
340
CHAPTER 24
Vscope =
(0.347 M 69.68)(100 V 0)
ZsVi =
Z s Z p (0.121 M j 0.325 M ) + (1.086 M j 2.931 M )
34.70 106 V 69.68
3.470 106 69.68
1
10 V 0 =
(100 V 0)
10
=
CHAPTER 24
341
Chapter 25
1.
2.
I:
a.
no
b.
no
c.
yes
d.
no
e.
yes
II:
a.
yes
b.
yes
c.
yes
d.
yes
e.
no
III:
a.
yes
b.
yes
c.
no
d.
yes
e.
yes
IV:
a.
no
b.
no
c.
yes
d.
yes
e.
yes
b.
i=
c.
2Im 2
2
2
1 + cos(2ωt 90) cos(4ωt 90) + cos(6ωt 90) +
3
15
35
1 4
2
2
2
i = 2 I m 1 cos(2ωt 90)
cos(4ωt 90)
cos(6ωt 90)
15
35
4 3
2Im
Im 2Im
=
2
d.
2
2
2
cos (2ωt 90)
cos (4ωt 90) +
cos (6ωt 90) +
i = 2 I m 1 +
15
35
4 3
3.
342
a.
υ = 4 + 2 sin α
b.
υ = (sin α)2
CHAPTER 25
c.
4.
i = 2 2 cos α
a.
b.
CHAPTER 25
343
5.
a.
b.
c.
344
CHAPTER 25
6.
Vav = 100 V
a.
Veff =
(50 V)2 + (25 V) 2
= 107.53 V
2
Iav = 3 A
b.
Ieff =
7.
(100 V)2 +
(3 A)2 +
(2 A)2 + (0.8 A)2
= 3.36 A
2
a.
Veff =
(20 V) 2 + (15 V)2 + (10 V)2
= 19.04 V
2
b.
Ieff =
(6 A) 2 + (2 A) 2 + (1 A)2
= 4.53 A
2
8.
PT = V0I0 + V1I1 cos θ1 + + VnIn cos θn
(50 V)(2 A)
(25 V)(0.8 A)
cos 53 +
cos 70
= (100 V)(3 A) +
2
2
= 300 + (50)(0.6018) + (10)(0.3420)
= 333.52 W
9.
P=
10.
a.
DC: E = 18 V, Io =
b.
Ieff =
(20 V)(6 A)
(15 V)(2 A)
(10 V)(1 A)
cos 20 +
cos 30 +
cos 60
2
2
2
= 60(0.9397) + 15(0.866) + 5(0.5)
= 71.87 W
E 18 V
= 1.5 A
=
R 12
ω = 400 rad/s:
XL = ωL = (400 rad/s)(0.02 H) = 8
Z = 12 + j8 = 14.42 33.69
E
30 V/ 2 0
2.08 A
33.69
I= =
=
Z 14.42 33.69
2
2.08
i = 1.5 + 2
sin(400t 33.69)
2
i = 1.5 + 2.08 sin(400t 33.69)
CHAPTER 25
(1.5 A)2 +
(2.08 A) 2
= 2.10 A
2
345
c.
2.08 A
33.69 (12 0)
DC: υR = E = 18 V, VR =
2
24.96 V
=
33.69
2
24.96
υR = 18 + 2
sin(400t 33.69)
2
υR = 18 + 24.96 sin(400t 33.69)
d.
2
V Reff = (18 V ) +
e.
DC: VL = 0 V
(24.96 V ) 2
= 25.21 V
2
2.08 A
VL =
33.69 (8 90)
2
16.64 V
=
56.31
2
υL = 0 + 16.64 sin(400t + 56.31)
ω = 400 rad/s:
11.
346
(16.64 V)2
= 11.77 V
2
f.
2
V Leff = 0 +
g.
2
R = (2.101 A)2 12 = 52.97 W
P = I eff
a.
DC: IDC =
b.
Ieff =
c.
υR = iR = i(12 )
= 24 + 24.96 sin(400t 33.69) + 6 sin(800t 53.13)
d.
Veff =
24 V
=2A
12
ω = 400 rad/s:
Z = 12 + j(400 rad/s)(0.02 H) = 12 + j8 = 14.422 33.69
30 V 0
= 2.08 A 33.69 (peak values)
I=
14.422 33.69
ω = 800 rad/s:
Z = 12 Ω + j(800 rad/s)(0.02 H) = 12 + j16 = 20 53.13
10 V 0
= 0.5 A 53.13 (peak values)
I=
20 53.13
i = 2 + 2.08 sin(400t 33.69) + 0.5 sin(800t 53.13)
(2 A) 2 +
(2.08 A)2 + (0.5 A 2 )
= 2.51 A
2
(24 V) 2 +
(24.96 V) 2 + (6 V)2
= 30.09 V
2
CHAPTER 25
e.
12.
DC: VL = 0 V
ω = 400 rad/s:
VL = (2.08 A 33.69)(8 90)
= 16.64 V 56.31
ω = 800 rad/s: VL = (0.5 A 53.13)(16 90)
= 8 V 36.87
υL = 0 + 16.64 sin(400t + 56.31) + 8 sin(800t + 36.87)
(0) 2 +
(16.64 V) 2 + (8 V) 2
= 13.06 V
2
f.
Veff =
g.
2
PT = I eff
R = (2.508 A)2 12 = 75.48 W
a.
DC: I =
b.
Ieff =
c.
DC: V = IR = (5 A)(12 ) = 60 V
VR = (1.054 A 26.57)(12 0)
= 12.648 V 26.57
ω = 600 rad/s: VR = (0.417 A 45)(12 0)
= 5 V 45
υR = 60 + (1.414)(12.648)sin(300t 26.57) (1.414)(5)sin(600t 45)
υR = 60 + 17.88 sin(300t 26.57) 7.07 sin(600t 45)
d.
2
V Reff = (60 V ) +
60 V
= 5A
12
ω = 300 rad/s: XL = ωL = (300 rad/s)(0.02 H) = 6
Z = 12 + j6 = 13.42 26.57
E = (0.707)(20 V) 0 = 14.14 V 0
E
14.14 V 0
= 1.054 A 26.57
I= =
Z 13.42 26.57
ω = 600 rad/s: XL = ωL = (600 rad/s)(0.02 H) = 12
Z = 12 + j12 = 16.97 45
E = (0.707)(10 V) 0 = 7.07 V 0
7.07 V 0
E
= 0.417 A 45
I= =
16.97 45
Z
i = 5 + (1.414)(1.054)sin(300t 26.57) (1.414)(0.417)sin(600t 45)
i = 5 + 1.49 sin(300t 26.57) 0.59 sin(600t 45)
(5 A) 2 +
(1.49 A) 2 + (0.59 A) 2
= 5.13 A
2
ω = 300 rad/s:
CHAPTER 25
(17.88 V ) 2 + (7.07 V ) 2
= 61.52 V
2
347
e.
DC: VL = 0 V
ω = 300 rad/s:
ω = 600 rad/s:
VL = (1.054 A 26.57)(6 90) = 6.324 V 63.43
VL = (0.417 A 45)(12 90) = 5 V 45
υL = 0 + (1.414)(6.324)sin(300t + 63.43) (1.414)(5)sin(600t + 45)
υL = 8.94 sin(300t + 63.43) 7.07 sin(600t + 45)
13.
f.
(8.94 V ) 2 + (3.54 V ) 2
= 6.8 V
V Leff =
2
g.
2
P = I eff
R = (5.13 A)2 12 = 315.8 W
a.
DC: I = 0 A
1
1
=
= 20
ωC (400 rad/s)(125 F)
Z = 15 j20 = 25 53.13
E = (0.707)(30 V) 0 = 21.21 V 0
E
21.21 V 0
= 0.848 A 53.13
I= =
Z 25 53.13
i = 0 + (1.414)(0.848)sin(400t + 53.13)
i = 1.2 sin(400t + 53.13)
ω = 400 rad/s:
b.
c.
348
XC =
(1.2 A) 2
= 0.85 A as above
2
Ieff =
DC: VR = 0 V
ω = 400 rad/s:
VR = (0.848 A 53.13)(15 0) = 12.72 V 53.13
υR = 0 + (1.414)(12.72)sin(400t + 53.13)
υR = 18 sin(400t + 53.13)
(18 V ) 2
= 12.73 V
2
d.
V Reff =
e.
DC: VC = 18 V
ω = 400 rad/s: VC = (0.848 A 53.13)(20 90)
= 16.96 V 36.87
υC = 18 + (1.414)(16.96)sin(400t 36.87)
υC = 18 + 23.98 sin(400t 36.87)
f.
2
V C eff = (18 V ) +
g.
2
R = (0.848 A)2 15 = 10.79 W
P = I eff
(23.98 V ) 2
= 24.73 V
2
CHAPTER 25
14.
a.
400
400
cos 4ωt
cos 2ωt
3
15
= 63.69 + 42.46 sin(2ωt + 90) 8.49 sin(4ωt + 90)
ω = 377 rad/s:
e = 63.69 + 42.46 sin(754t + 90) 8.49 sin(1508t + 90)
e=
200
DC: XL = 0 VL = 0 V
1
ω = 754 rad/s: XC = 1 =
= 1330
ωC (754 rad/s)(1 F)
XL = ωL = (754 rad/s)(0.1 H) = 75.4
Z = (1 k 0) 75.4 90 = 75.19 85.69
E = (0.707)(42.46 V) 90 = 30.02 V 90
Z(E)
(75.19 85.69)(30.02 V 90)
Vo =
= 1.799 V 94.57
=
Z + ZC 75.19 85.69 + 1330 90
ω = 1508 rad/s:
XC =
1
1
=
= 6631.13
ωC (1508 rad/s)(1 F)
XL = ωL = (1508 rad/s)(0.1 H) = 150.8
Z = (1 k 0) 150.8 90 = 149.12 81.42
E = (0.707)(8.49 V) 90 = 6 V 90
Z(E)
(149.12 81.42)(6 V 90)
Vo =
=
Z + ZC 149.12 81.42 + 6631.13 90
= 1.73 V 101.1
υo = 0 + 1.414(1.799)sin(754t 94.57) 1.414(1.73)sin(1508t 101.1)
υo = 2.54 sin(754t 94.57) 2.45 sin(1508t 101.1)
15.
b.
Voeff =
c.
P=
(2.54 V ) 2 + (2.45 V ) 2
= 2.50 V
2
( V eff ) 2 (2.50 V ) 2
= 6.25 mW
=
R
1k
i = 0.318Im + 0.500 Im sin ωt 0.212Im cos 2ωt 0.0424Im cos 4ωt + (Im = 10 mA)
i = 3.18 103 + 5 103 sin ωt 2.12 103 sin(2ωt + 90)
0.424 103 sin(4ωt + 90) +
i 3.18 103 + 5 103 sin ωt 2.12 103 sin(2ωt + 90)
DC: Io = 0 A, Vo = 0 V
ω = 377 rad/s;
XL = ωL = (377 rad/s)(1.2 mH) = 0.452
1
1
XC =
=
= 13.26
C 377 rad/s (200 F)
Z = 200 j13.26 = 200.44 3.79
I = (0.707)(5 103)A 0 = 3.54 mA 0
ZLI
(0.452 90)(3.54 mA 0)
= 7.98 μA 93.66
Io =
=
ZL + Z
j 0.452 + 200 j13.26
CHAPTER 25
349
Vo = (7.98 μA 93.66)(200 0) = 1.596 mV 93.66
XL = ωL = (754 rad/s)(1.2 mH) = 0.905
1
1
=
= 6.63
XC =
ωC (754 rad/s)(200 F)
ω = 754 rad/s:
Z = 200 j6.63 = 200.11 1.9
I = (0.707)(2.12 mA) 90 = 1.5 mA 90
Z LI
(0.905 90)(1.5 mA 90)
Io =
= 6.8 μA 181.64
=
Z L + Z
j 0.905 + 200 j 6.63
Vo = (6.8 µA 181.64)(200 0) = 1.36 mA 181.64
υo = 0 + (1.414)(1.596 103)sin(377t + 93.66)
(1.414)(1.360 103)sin(754t + 181.64)
3
υo = 2.26 10 sin(377t + 93.66) + 1.92 103 sin(754t + 1.64)
16.
a.
b.
17.
350
60 + 70 sin ωt + 20 sin(2ωt + 90) + 10 sin(3ωt + 60)
+20 + 30 sin ωt 20 sin(2ωt + 90) + 5 sin(3ωt + 90)
DC: 60 + 20 = 80
ω: 70 + 30 = 100 100 sin ωt
2ω: 0
3ω: 10 60 + 590 = 5 + j8.66 + j5 = 5 + j13.66 = 14.55 69.9
Sum = 80 + 100 sin ωt + 14.55 sin(3ωt + 69.9)
20 + 60 sin α + 10 sin(2α 180) + 5 sin(3α + 180)
5 + 10 sin α +
0
4 sin(3α 30)
DC: 20 5 = 15
α:
60 + 10 = 70 70 sin α
2α: 10 sin(2α 180)
3α: 5 180 4 30 = 5 [3.46 j2] = 8.46 + j2
= 8.69 166.7
Sum = 15 + 70 sin α + 10 sin(2α 180) + 8.69 sin(3α + 166.7)
iT = i1 + i2
= 10 + 30 sin 20t
0.5 sin(40t+ 90)
+20 + 4 sin(20t + 90) + 0.5 sin(40t+ 30)
DC: 10 A + 20 A = 30 A
ω = 20 rad/s: 30 A 0 + 4 A 90 = 30 A + j4 A = 30.27 A 7.59
ω = 40 rad/s: 0.5 A 90 + 0.5 A 30
= j0.5 A + 0.433 A + j0.25 A
= 0.433 A j0.25 A = 0.5 A 30
iT = 30 + 30.27 sin(20t + 7.59) + 0.5 sin(40t 30)
CHAPTER 25
18.
e = υ1 + υ2
= 20 200 sin 600t + 100 sin(1200t + 90) + 75 sin 1800t
+ 50 sin(1800t + 60)
10 + 150 sin(600t + 30)
+0
DC: 20 V 10 V = 10 V
ω: 600 rad/s: 200 V 0 + 150 V 30 = 102.66 V 133.07
ω = 1200 rad/s: 100 sin(1200t + 90)
ω = 1800 rad/s: 75 V 0 + 50 V 60 = 108.97 V 23.41
e = 10 + 102.66 sin(600t + 133.07) + 100 sin(1200t + 90) + 108.97 sin(1800t + 23.41)
CHAPTER 25
351
Chapter 26
Ei
V
1.05 1.00 V 50 mV
; Ii = R
= 1.064 mA
Ii
R
47
47
E
1.05 V
= 986.84 Ω
Zi = i
I i 1.064 mA
1.
Zi =
2.
Zi =
3.
a.
I i1
b.
Z i2
c.
Ei3 I i3 Z i3 = (1.5 mA)(4.6 kΩ) = 6.9 V
Ei
120 V 0
= 19.35 Ω 10.8° = 19 Ω + j3.623 Ω
I i 6.2 A 10.8
XL
3.623
f = 60 Hz: R = 19 Ω, L =
= 9.61 mH
2 f 2 (60 Hz)
Ei1
Z i1
Ei2
I i2
E g Eo
20 mV
= 10 μA
2 k
1.8 V
= 4.5 kΩ
0.4 mA
4 V 3.8 V 0.2 V
= 0.1 mA(p p)
2 k
2 k
Rs
E
3.8 V(p p )
= 38 kΩ
Zo = o
I o 0.1 mA( p p )
4.
Io =
5.
Eopeak Eg peak VRpeak = 2 V 0° 40 × 103 V 0° = 1.96 V 0°
VRpeak
40 mV
= 43.96 µA
Rs
0.91 k
E 1.96 V 0
Zo = o
= 44.59 kΩ
43.96 A
IR
Ipeak =
6.
Eopeak 2 0.6 V(rms) = 0.849 V
Eo( p p ) 2 Eo( peak ) = 2(0.849 V) = 1.697 V
E g Eo
18 V 1.697 V
= 51.5 µA(p p)
2 k
Rs
E 1.697 V( p p)
Zo = o
= 32.95 kΩ
I o 51.5 A(p p )
Io =
352
CHAPTER 26
7.
Zo =
Eo p p
I o p p
Eg p p VRp p
I o p p
0.8 V 0.4 V
= 10 kΩ
40 A
VR p p 2 div 0.2 V/div. = 0.4 V
E g p p 4 div 0.2 V/div. = 0.8 V
I o p p
8.
VR p p
10 k
0.4 V
= 40 μA
10 k
Ei = IiZi = (10 µA 0°)(1.8 kΩ 0°) = 18 mV 0°
E i(peak) 2 (18 mV) = 25.46 mV
Ei( p p ) = 2(25.46 mV) = 50.92 mV
A NL
9.
Eo
4.05 V180
= 79.54 180° = 79.54
Ei 50.92 mV 0
Eo
RL
(5.6 k)
= 392.98
A NL
(3200)
Ei
5.6 k 40 k
RL Ro
E
E E
o o i
E g Ei E g
a.
A
b.
AT
with Ei =
AT
10.
Zi E g
Zi Rg
and
Ei
Zi
E g Zi + Rg
Eo
Zi
(2.2 k)
(392.98)
= 320.21
2.2 k 0.5 k
Ei Zi Rg
1400 mV
= 1200
1.2 mV 0
192 mV
A
= 160
1.2 mV
A
Ro RL NL 1
A
A NL
1200
4.7 k
1
160
30.55 k
11.
a.
Eo
RL
A NL
RL Ro
Ei
2 k
160 = A NL
= A NL (0.0667)
2 k 28 k
A NL = 2398.8
A
CHAPTER 26
353
b.
c.
Eo = IoRL = (4 mA)(2 kΩ) = 8 V
E
A = o = 160
Ei
Eo
8 V
= 50 mV
Ei =
160 160 V
Ii =
Zi =
12.
E g Ei
Rg
70 mV 50 mV
= 50 µA
0.4 k
Ei 50 mV
= 1 kΩ
I i 50 A
Ri
RL Ro
(3200)(2.2 k)
=
5.6 k 40 k
= 154.39
a.
Ai = A NL
b.
Rg Z i
A iT AT
RL
A Z
i
Zi R g
A iT A
Rg Z i
RL
Zi
RL Z i
A NL
RL
RL Ro RL
A NL
Zi
RL Ro
(3200)(2.2 k)
5.6 k 40 k
154.39
13.
c.
Same result since Ii = Ig
a.
A G A2
Ri
RL
( 392.98) 2
A = A NL
2.2 k
5.6 k
6.067 ×104
A G A A i
(392.98)(154.39)
6.067 ×104
RL
RL Ro
5.6 k
(3200)
5.6 k 40 k
392.98
A i = A NL
Ri
RL Ro
2.2 k
(3200)
5.6 k 40 k
154.39
354
CHAPTER 26
b.
AT A
Zi
2.2 k
(392.98)
= 320.21
2.2 k 0.5 k
Zi Rg
A iT AT
Rg Z i
RL
0.5 k 2.2 k
(320.21)
= 154.39
5.6 k
Rg Ri
0.5 k 2.2 k
( 320.21) 2
= 4.94 × 104
A GT A2T
5.6 k
RL
A GT AT A iT (320.21)(154.39) = 494 × 104
14.
a.
Ai
Io
Z
A i
Ii
RL
(160)(0.75 k)
2 k
60
b.
A GT
PL
A2T
Pg
AT A
Rg Ri
R
L
Zi
Z i Rg
(160)(0.75 k)
104.35
0.75 k 0.4 k
0.4 k 0.75 k
A GT (104.35) 2
2 k
= 6.261 × 103
15.
a.
AT A1 A2 = (30)(50) = 1500
b.
A iT AT
c.
A i1 A1
ZiL
A i2 A2
16.
RL
1 k
= 187.5
(1500)
8 k
1 k
(30)
= 15
2 k
RL1
Zi1
Zi2
RL2
2 k
(50)
= 12.5
8 k
d.
A iT A i1 A i2 = (15)(12.5) = 187.5 as above
a.
AT A1 A2 A3
6912 = (12) A 2 (32)
A2 = 18
CHAPTER 26
355
b.
A i1
4=
A1 Zi1
RL1
A1 Zi1
Zi2
(12)(1 k)
Z i2
Z i2 = 3 kΩ
c.
A i3
A3 Zi3
RL3
(32)(2 k)
2.2 k
= 29.09
A iT A i1 A i2 A i3
= (4)(26)(29.09)
= 3.025 × 103
17.
a.
z11 =
z11 =
E1
I1
Z1 (Z 2 Z3 )
I2 0
Z1Z 2 Z1Z 3
Z1 + Z 2 Z3
Z3I 2
Z1 + Z 2 Z3
(Z3I 2 )(Z1 )
E1 = I1Z1 =
Z1 + Z 2 Z3
I=
z12 =
z21 =
E2
I1
E2
I2
I1 0
Z1I 3
Z1 + Z 2 Z3
Mirror image of z12
I2 0
z 21
z22 =
E1
I2
Z1Z 3
Z1 + Z 2 Z3
Mirror image of z11
I1 0
z 22 Z3 (Z1 Z 2 )
356
Z1Z3 Z 2 Z3
Z1 + Z 2 Z3
CHAPTER 26
b.
18.
z11
a.
E1
I1
I2 0
z11 R4 R2 ( R1 R3 )
`
R4
z12
E1
I2
R2 ( R1 R3 )
R1 R2 R3
I1 0
R2 (I 2 )
( R1 R2 ) R3
E1 I R2 I 2 R4
I
and z12 =
R2 R3I 2
R4 I 2
R1 R2 R3
R2 R3
R R R4 ( R1 R2 R3 )
E1
R4 2 3
R1 R2 R3
I 2 R1 R2 R3
E2 = I R3 I1 R4
R2 (I1 )
CDR: I =
( R1 R3 ) R2
R2 R3I1
E2 =
+ I1R4
R1 R2 R3
and z21 =
z 22
E2
I2
R2 R3
R R R4 ( R1 R2 R3 )
E2
R4 2 3
R1 R2 R3
I1 R1 R2 R3
I1 0
Z22 = R4 R3 ( R1 R2 )
R ( R R2 )
= R4 3 1
R3 ( R1 R2 )
CHAPTER 26
357
19.
a.
y11 =
I1
E1
YT Y1 (Y2 Y3 )
E2 0
Y1 (Y2 Y3 )
Y1 Y2 Y3
Y1Y2 Y1Y3
Y1 Y2 Y3
Nodal Analysis:
V [Y1 Y2 Y3 ] E2Y2
V = I1/Y1
and
I1
[Y1 Y2 Y3 ] E 2 Y2
Y1
y12 =
y21 =
I2
E1
I2
E2
E1 0
Y1Y2
Y1 Y2 Y3
Mirror image of y12
E2 0
y 21
y22 =
I1
E2
Y1Y2
Y1 Y2 Y3
Mirror image of y11
E1 0
y 22 YT Y2 (Y1 Y3 )
20.
a.
y11 =
I1
E1
Y1Y2 Y1Y3
Y1 Y2 Y3
E2 0
y11 Y1 Y2 Y4
Y1
358
Y2 Y4
Y2 Y4
Y1 (Y2 + Y4 ) Y2 Y4
Y2 Y4
CHAPTER 26
y21 =
E1 =
I2
E1
(using the above diagram)
E2 0
I
1
I2
I
1
(E + E) = 2 2 I 2
Y1
Y2 Y4
Y2 Y4
Y Y2
I
YY
and E1 = I 2 4
with y21 = 2 2 4
E1
Y2 Y4
Y4 Y2
y11 =
E2 =
E2 0
I
1
I1
I
1
(E + E ) = 1 1 I1
Y3
Y2 Y4
Y2 Y4
and y12 =
y22 =
I2
E1
I2
E2
Y2 Y4
= y21
Y2 Y4
y22 = Y3 + Y2 Y4 = Y3 +
E1 0
=
Y2 Y4
Y2 Y4
Y3 (Y2 + Y4 ) + Y2 Y4
Y2 Y4
21.
h11 =
E1
I1
= ZT = Z1 Z 2
E2 0
Z1Z 2
Z1 + Z 2
Using the above figure:
Z1 (I1 )
CDR: I2 =
Z1 + Z 2
h11 =
I2
I1
CHAPTER 26
=
E2 0
Z1
Z1 + Z 2
359
h12 =
E1
E2
I1 0
VDR: E1 =
h12 =
E1
E2
Z1E 2
Z1 + Z 2
=
I1 0
Z1
Z1 + Z 2
Using above figure:
h22 =
I2
E2
: Z = Z 3 (Z1 Z 2 )
I1 0
Z1Z3 Z 2 Z3
Z1 + Z 2 Z3
1 Z1 Z 2 + Z3
h22 =
Z Z1Z3 Z 2 Z3
22.
a.
h11 =
E1
I1
E2 0
= Z i R1 (R 2 R 3 R 4 )
h12 =
E1
E2
I1 0
E1 = I R2 I 2 R4
R3 (I 2 )
I
R1 R2 R3
R2 R3I 2
E1
I 2 R4
R1 R2 R3
E
E2
and I2 = 2
Z R4 R3 ( R1 R 2 )
R2 R3
E2
E1 =
R4
R1 R2 R3
R R3 R1 R2 R3
4 R1 R2 R3
and h12 =
360
R2 R3 R4 ( R1 R2 R3 )
E1
E 2 R1 R3 R2 R3 R4 ( R1 R2 R3 )
CHAPTER 26
Z R2 R3 R4
(Z )(I1 )
I R1
Z + R1
RI
I 1 1
R1 Z
R4 I
R4 R1 (I1 )
R4 R3 R4 R3 R1 Z
R1 R4 I1
( R3 R4 )( R1 Z )
I R3
I 2 = I R1 I R3
h22 =
I2
I1
E2 0
Z
R1 R4
Z + R1 ( R3 R4 )( R1 Z )
h22 =
I2
E2
Z I1
R1 R4 I1
Z + R1 ( R3 R4 )( R1 Z )
I1 0
R1 R4
1
Z
R1 Z
R3 R4
1
ZT
ZT R4 R3 ( R1 R2 )
1
h22 =
R4 R3 ( R1 R2 )
A Y- conversion would have simplified the problem to on similar to Fig 26.70.
23.
h11 =
E1
I1
E2 0
Y Y1 (Y2 Y3 )
Y1Y2 Y1Y3
Y1 Y2 Y3
1 Y1 Y2 + Y3
h11 =
Y Y1Y2 Y1Y3
Y
h21 =
I2
I1
CHAPTER 26
E2 0
361
From above figure:
Z3I1
I1/Y3
CDR: I2 =
Z3 + Z 2 1/Y3 1/Y2
and h21 =
I2
I1
E2 0
1/Y3
Y2
1/Y3 1/Y2 Y2 Y3
h12 =
E1
E2
I1 0
Z 3E2
1/Y3E 2
Z3 + Z 2 1/Y3 1/Y2
Y2 E 2
And E1 =
Y2 Y3
VDR: E1 =
with h12 =
h22 =
h22 =
I2
E2
I2
E2
Y =
I1 0
I1 0
: CDR I2 =
E2 0
=
and h21 =
362
I1 0
Y2
Y2 + Y3
Y2 Y3
Y2 + Y3
= Y =
h11 =
I2
I1
=
Y2 Y3
(from above figure)
Y2 + Y3
24.
h21 =
E1
E2
E1
I1
E2 0
1
1
YT Y1 Y2 Y4
Z1 (I1 )
1/ Y1 (I1 )
Z1 + Z 2 + Z 4 1/Y1 1/Y2 1/Y4
1/ Y1 (I1 )
Y2 Y4 Y1Y4 Y1Y2
Y1Y2 Y4
Y2 Y4
Y2 Y4 Y1Y4 Y1Y2
CHAPTER 26
h11 =
E1
E2
I1 0
VDR: E1
I2
E2
1/Y1 (E 2 )
1/Y1 1/Y2 1/Y4
Y2 Y4
Y2 Y4 Y1Y4 Y1Y2
and h12 =
h22 =
Z1 (E 2 )
Z1 + Z 2 + Z 4
= YT (using the above figure)
I1 0
YT = Y3 Y1 Y2 Y4
Y1Y2 Y4
= Y3
Y1Y2 Y1Y4 Y2 Y4
25.
a.
b.
Eq. 26.45:
hf
Ai =
1 ho Z L
a.
= 47.62
Zi =
h f ZL
hi (1 ho Z L ) hr h f Z L
50(2 k)
99
1 k(1 0.05) (4 104 )(50)(2 k)
hr h f Z L
E1
hi
I1
1 ho Z L
1 k
b.
1
1
(2 k)
40 k
Eq. 26.46:
A
26.
50
Zo =
ho
CHAPTER 26
(4 104 )(50)(2 k)
961.9
1
1
(2
k
)
40 k
1
hr h f
hi Rs
1
200 k
1
(4 104 )(50)
40 k
1 k 0
363
27.
Z11 = 1 kΩ 0°, z12 = 5 kΩ 90°, z21 = 10 kΩ 0°, z22 = 2 kΩ j4 kΩ, ZL = 1 kΩ 0°
z z
E
(5 k 90)(10 k)
= 9,219.5 Ω 139.40°
z11 12 21 1 k
I
z 22 Z L
2 k j 4 k 1 k
E
z z
(5 k 90)(10 k)
= 29.07 kΩ 86.05°
Zo = 2 z 22 12 21 2 k j 4 k
I2
Rs z11
1 k 1 k
Zi =
28.
1/ y 22 Z L
1/ y 22 + Z L
ZL
1 y 22 Z L
1/ y 22 Z L
ZL
E2 = y21E1
1 y 22 Z L
ZL
I1 = E1y11 + y12E2 = E1y11 + y12 y 21E1
1 y 22 Z L
I1
y y Z
y11 12 21 L
1 y 22 Z L
E1
E
1
and Zi = 1
y y Z
I1
y11 12 21 L
1 y 22 Z L
364
CHAPTER 26
1
Rs
y12 E 2 y12 E 2 y12 Rs E 2
E1 =
1
Y
y11 Rs 1
y11
Rs
Y y11
y R E
I2 = y21E1 + y22E2 = y22 12 s 2 + y22E2
y11 Rs 1
I2
y y R
12 21 s + y22
E2
y11 Rs 1
and Zo =
29.
30.
E2
I2
=
E1 0
1
y y R
y 22 12 21 s
1 y11 Rs
z11z 22 z12 z 21 (4 k)(4 k) (2 k)(3 k)
= 2.5 kΩ
4 k
z 22
z
2 k
h12 = 12
= 0.5
z 22 4 k
z
3 k
= 0.75
h12 = 21
z 22 4 k
1
1
= 0.25 mS
h22 =
z 22 4 k
h11 =
a.
h = h11h22 h12h21 = (103)(20 × 106) (2 × 104)(100)
= 20 × 103 20 × 103 = 0
h
2 104
= 10 Ω
z11 = h = 0 Ω, z12 = 12
Z 22
h12 20 106 S
h 21
100
1
= 5 MΩ, z22 =
z21 =
= 50 Ω
6
h 22
h 22
20 10 S
b.
y11 =
h12 2 104
1
1
= 2 × 107 S
= 103 S, y12 =
3
h11
h11 10
103
h
100
y21 = 21 3
= 100 × 103 S, y22 = h = 0 S
h11
h11 10
CHAPTER 26
365