电路原理_第三版_范承志_课后答案[1-11章].

1
1 C=1uF )
1-1
,
i=2+t A
t=0
uC 0
5V
uC =
WC=
(
1-1
uC (t ) uC (0) 5 106 5 (2t We
1 C
t 0
t 0
i ( )d )d
(2
1 2 t ) 106 V 2 1 10 2
6
1 CuC 2 2 5 10
7
5 (2t 1 2 t ) 106 2
1 2 t ) 106 2
IR
IL
IL
I2
2 IR
3A
3-10 3- 11 50Hz 3- 11 a R1
U
200V
R1
U1 100V
R L
U2
124V
R1 100
3-11
I
U U1 U 2
2 U 2 U12 U 2 2UU1
3- 11 b
cos
2002 1002 124 2 2 200 100
0.866
30 LI U sin
rad/s
2.5 105 rad/s
f0
2 L C
39.8 (kHz) 10k
Q
R
100
1-1
4-4 Us
R 4-1-7
L Us
C 50V 1A
103 rad/s
R L
C
50 F
4-4
Y
R R
2
( L) j ( BL
2
j BC )
L R
2
( L) 2
C
G
I
C
YU G
[G R R
2
j ( BL ( L) 2
200 200 200
2 cos 45 W 2 sin 45 var 2V A
200W 200 var
282V A
50Hz 1A 80W R L
100V
3-14
R
P I
2
80 1
2
80
Z
U I
802
100 1
100
XL
Z2
R2
1002
60
L
XL
60 H 0.19H 314
1-6
4-1
RLC
R
5
L=10mH 24V
C 1 F
Ans:
0
104 rad / s,
4.8 A, U L
UC
480V
4-2
RLC
R
50
2A
L=4mH
C 160 F
Ans:
0
1.25 103 rad / s,
2 A, I L
IC
20 A
4-3
4-3
R 100
C
4 10
Q
10
F
L
4 10 2 H
f0
4-3
0
1 LC
0
1 4 10
2
4 10
10
3 2
I 3 ( R1 R2 6I
3
0 13 A 6
I
3
43 A 6 I
2
I2
2-2
I
3
13 A 6
2-2
3
23 A 6
I4
I1 I
2
11A
, R7 =4 , I S 4 =6A, I S 5 =1A,
R1 = R5 =2
, R2 = R4 =1
, R3 = R6 =3
R1 , R2 , R3 , R4 , R5
0
3
:12 I 3 3 6 3 1 6 I 4 0 6I 3 2 6 1 1 0 4 :10 I 4 I
3
1A 0.5 A
I6
2-4 2
1A
4
I7
I
4
0.5 A R2
2
2
R3
3
R4
4
R5
5
U S 4 =4V
I1
I4
2
4
1
: ( R2 : ( R3 U3 I5
R3 ) I1 R2 I 5 R4 R5 ) I 4
1 A 7 0.4 A E3 6 8 4 18V R1 R2 R3
20 g 0.0375 S 0.5 U S
I1 Ud
2-25 10V 2
I3
R4 I 4
25
IS
1A
2
25
U1 U2 U
1 R2 1 R1
1 R3 1 R2
1 U2 R2 1 U1 R2
gU IS US R1
U 2 U1 U1 14V U2 22V U 8V
rm I 2 0.6 A
10V
(rm I 2
I 2 R2 rm I 2
20 10 10V
2-1
2
1
R1 =1
R2 =2
, R3 =3
, R4 =4
, IS5
5A, I S 6 =6A,
2 R1 , R3 , R4
1
l l l
I1 I
2
IS5 IS 6
6A 6A R3 ) R1 I 1 R3 I 5 18 0 I1 I1 I I3 I
R3 I 4
U3 US4
2
R3 I1 R5 I 5
R3 ( I1 I 4 ) I5 I4
5 I1 4 I 5 3I 4 6( I1 I 4 ) 12 I 4 3I1 10 I5 4 I 5 2 I5 I 4 I1
2-5
I4
0.8 A
2 5
R4
4
R5
5
R6
6
IS 7
7A, I S 8 =8A, I S 9 =9A,
P 3V IS
2
18
I ES ES
2-21
gES
IS
g 4
1V , I S 3V , I S
2 20
0 0
21
I=4A
I
12 A E1 =10V R5
2
E2 =7V
E3
4V
R1
5
R2 =7
R3
R4 =42
2
21
Rd
R5
R2 // R4
R1 // R3 12
I2
I4
E2 R2 E1 R1 R3 R3 I 3 R4
3 A;
20 3 W
3-6 50Hz Y
3-6
R 1000 , C
20 F
500V
i.
ans:
Y
0wenku.baidu.com001
j 0.0063s , i
2 3.2sin(314t 810 ) A
3-6
3- 7
L 31.8 10 3 H
i f
2 sin( t 60 )A 5000Hz
I 1
f
uL 60 A
50Hz
uL
f
50Hz
I
BC )]U
L R
2
( L) 2
C G BL R ( L) 2
GU
R
2
I U
0.02S
R
2
L ( L)2
YL G
C 103 50 10 6 S 0.05S
jBL (0.02 j 0.05)S
ZL
1 YL
1 0.02 j 0.05
R 6.9
U=25V U 5V
Ibc
Ub Uc
2-17 2-17
IS
1A
U=15V
US IS
US
IS
U=5V
2-17
U
US
rI S U A r UA
15 5 25 5 5 5
r UA r UA 1 r 10
5 10 10
ES
U A 10V
5V
ES 0A I 1V
IS
2-18 IS 0A,
1A
2
U
18 I=4A
UC 100 30 V
3-6 -4
IC
j
1 UC XC
1 60 A
iC
2
2 sin(314t 60 )A
XC 100
3-6-5
IC
0.5 30 A UC uC jX C I C 50
60 V
250 sin( t 60 )V
1-3
3- 10 L
3- 10a
I
5A
IR
4A
IL Us
IR Us I
3A
3-7-2b
IS U ab
100mA
R0
20
R1 100
IS
1
18
I u1 U ab PIS
E R0 R1
12 120
0.1A
IR1 10V u1 IS u1 u1
u1 10V 20V 0.1 10 1W
1
19 5
1
19 I
E=20V
R1
R2
10
R=50
rm
U ab
1
19
I2 I U ab
E
R2
2A E) R
I U sin I
U1 R1
100 A 1A 100 200 0.5 H 0.318H 314 73.2
L R U cos I U1
200 0.866 100 1
1-4
3- 12
3- 12
U
220V
I
30
XL
10
UL
U
U
3-12 XL N XL N
ZN
10
30 Z ZN jX L 10 30 j10
10 30
I
U
3- 13 3- 13
U 22A z Iz N 220V
R XL 100
U
200V
3-13
U
200 0 V
Z
R
jX L
(100
j100)
2 100 45
I
U Z
200 0 A 2 100 45
2
45 A
0 ( 45 ) 45
1-5
P UI cos Q UI sin S UI
3- 14 3- 14
(2) u (3)
2 100sin(314t 900 ) V ; i
3- 3 u
3- 3
u1
u
2 40 sin t
u1 u2
u2
2 30 sin( t 90 )
U U1 U 2
U1
40 0 V U
u
U2
30 90 V 40 0 V 30 90 V (40 u j 30)V 50 36.9 V
U1 U 2
2
5
( R4 15 I I1 I4
2-7
R5
R6 ) I
R6 I S 9
R4 I S 7 I I2 I5 IS 7 I
R5 I S 8
0
54 28 40 0 IS7 I IS9 IS 7 16 A 11.4 A
2-7
4.4 A IS8 IS 8 R1 15 A 3.6 A R2
10
I3 I6
IS8 I R3
2 50 sin( t 36.9 )V
1-1
3-4
u1 u2 2 200sin( t 30 )V
u
2 220sin( t 70 )V ,
u1 u2
Ans:
u
2 270 sin(6280t 230 )V
3-5
L 20mH
U 2
iL
2 sin1000tA
20V
1
du / dt
0
ans:
(1) 40V; (2)
5
IS9 IS 9
1A 4.6 A R4 U1 R8
12
R5 U3
R6
R7
4
U S 1 10V
IS 4
3.5 A
I S 8 =5/6A
U2
2-7
U1
1 R4 1 R5
1 R5 1 R6
1 R3 1 R7
1 R1 U1 R2
U2
1 1 U3 R5 R3 0
1 R1 R2
IS 4
U S1 R1 R2
U2
I6
I7
2-2
l
l l
l
1
:I 1 :I
2
IS 4 IS5
6A 1A R3 R3 R4 R5
4
2
3
: ( R1 R2 : ( R1 R2
R6 ) I
3
( R1 R4 ) I 1 ( R2 R3 ) I I I
3 4 3
R5 ) I
2
2
( R1 R2
R3 ) I
4
0
4
R7 ) I
( R1 R2
R1 I 1 R2 I
3-1
u
311sin 314t
3
6
V
1
2
t
0
t
0.015s
Ans:
(1) 311,
6
, 50Hz, 0.02S;
(3) 155.5V,-269V
3-2
100V 1 u i u 3
5A u i
50Hz 2 i
1 4
(1) u
Ans:
2 100sin 314t V ; i
2 5sin(314t 900 ) A 2 5sin 314t A
2A
I4 I6 I6
0 0 0 I
R=5
c : I1 I I1
1 15 2
1 A 6
1
I4
15 I
1 A 2
I 5 1A
I6
1 A 3 I S1
5 A 6 IS 2
1A
3 A 2 R1 1 R2
U
U1
U2
1
15
KCL
I
I S1 I S 2
3A
U RI 5 3 15V U1 U I S 1 R1 15 2 17V U2 U I S 2 R2 15 2 17V E1 E2 =8V R=7
1
16
1
16
6V
I
1
16
U
E1 E2 14V
I
U
R
14
7
2A
1
17
1
17
US
36W
R1
18W
US
R2
R3
1
17
US I IR2 R2
1
U R1 36 6
P R1 6A
18 2 I R1
6V U R1 R1 3A
P
US I
I R1 2 6 3 2 1A IR2
1 1
US
6
18
R3
US
2
3
E=12V
18
1 1 U3 R5 R7
U3
1 R7
1 R8
1 R3 U2
1 R1 R2 26 V 3
U1
1 R3
1 R1 R2
U2
1 R7
IS8
U S1 R1 R2
U1 14V
2-8 d
U 3 12V
2-8
2-8
Ua Ub Uc
E3 1 1 Ua R5 R5 1 R6 1 R7 I bc IS 4 E7 R7 I7 I7 E7 U C R7 US
j10, Z 2
j 50, Z 3 100 ,
3-8 ans:
I1
4.09
680 A, I 2
C
3.66
94.60 A, I 3 1.83
u
4.60 A
2 100 sin(314t 30 )V
UC
3- 9
31.85 F iC
iC
1
2 0.5 sin(314t 30 )A 314 rad/s
XC
1 100 C
r=10
(
)
I
1-4
I1
I S1 rI1 I
0.5 A 5V rI1 rI1 R 5 IR R 50 (I IS ) R I 0.1 1
I
IS
0.1 A
0.9 A
1
5
1-5
3
1-5 6
KCL
KVL
6 I1 1 2
1V 2I 4 1 I5 3I 6 a : I1 I b : I3 I4 1V 2 1 1V I5 I3 I5 I5 I3
2
2
J
5 (2t
J
1
2
1-2
U0 / Ui
RL
1-2
U0 U0 Ui Ui RL
I 0 RL kI
k I I i RL RL R Pi U i Ii
kI
Ui RL R
P U 0 I0
U 0 kI Ii
kIU 0 Ii
k I2
RL U i Ii R
R=50
1
4
1-4
I S 1 =0.5A I S =1A
U0 U1 U2 U1 I3 I1 Rd
U1 U 1 R1 6V U1 R3
U
14 4 10V
(U 2 U1 ) 1 R2 1 U1 R2 IS U US R1 12V 0.45 A Id IS I1 gU I3 0.75 A
U 2 18V 0.3 A gU 0.4 A
US U2 R1 U0 Id 13.33
3
XL
L
2 fL 314 31.8 10 UL jX L I 10 30 V
10
1-2
uL
2 10 sin( t 30 )V f 5000Hz XL 2 fL 31400 31.8 10 uL
3
1000
UL
jX L I 1000 30 V
2 1000 sin( t 30 )V
3-8
3-18
U
220 0 V , Z1