电路理论基础第二版答案
【篇一:潘双来版电路理论基础答案】>第一章
1-1. (a)、(b)吸收10w;(c)、(d)发出10w.
1-2. –1a; –10v; –1a; – 4mw.
1.8cos22t w.
1-4. u =104 i ; u = -104 i ; u =2000i ; u = -104 i ;
1-5.
1-6. 0.1a.
1-7.
1-8. 2?f; 4?c; 0; 4?j.
1-9. 9.6v,0.192w, 1.152mj;
16v, 0, 3.2mj.
1-10. 1– e-106 ta , t 0 取s .
1-11. 3h, 6(1– t )2 j; 3mh,
6(1–1000 t ) 2 mj;
1-12. 0.4f, 0 .
1-13. 供12w; 吸40w;
吸2w; (2v)供26w, (5a)吸10w.
1-14. –40v, –1ma; –50v, –1
ma; 50v, 1ma.
1-15. 0.5a,1w; 2a,4w; –1a, –2w; 1a,2w.
1-16. 10v,50w;50v,250w;–3v,–15w;2v,10w.
1-17. (a)2v;r耗4/3w;us : –2/3w, is : 2w;
(b) –3v; r耗3w; us : –2w, is :5w;
(c)2v,–3v; r耗4w;3w;us :2w, is :5w;
1-18. 24v, 发72w; 3a, 吸15w;
1-19. 0,us/rl ,us ;us/r1 ,us/r1 , –us rf /r1 .
1-20. 6a, 4a, 2a, 1a, 4a; 8v, –10v, 18v.
1-21. k打开:(a)0, 0, 0; (b)10v, 0, 10v;
(c)10v,10v,0; k闭合: (a)10v,4v,6v;
(b)4v,4v,0; (c)4v,0,4v;
1-22. 2v; 7v; 3.25v; 2v.
1-24. 14v.
1-25. –2.333v, 1.333a; 0.4v, 0.8a.
1-26. 80v.※
第二章
2-2. , .
2-4. 400v;363.6v;ia=.5a, 电流表及滑线电阻损坏. 2-11. –75ma; –0.5a.
2-14.1.6v,-24v
2-15. (a) (b) –2 a↓, 吸20w.
2-16.
2-17. 3a.
2-18. 7.33v.
2-19. 86.76w.
2-20. 1v, 4w.
2-21. 64w.
2-22.电压源发50w,电流源发1050w
2-23
2-24. 7v, 3a; 8v,1a.
2-25. 4v, 2.5v, 2v.
2-27. 60v.
2-28. 4.5v.
2-29. –18v.
2-30. 原构成无解的矛盾方程组; (改后)4v,10v.
2-31
2-32.2.5a
2-33. 3.33 k?, 50 k?.
2-34 加法运算
2-35. r3 (r1 +r2 ) is /r1 .
2-36. 可证明 i l =- us /r3 .
2-37. –2 ; 4 . ※
第三章
3-1. 44v;–1+9=8v; 6+9=15v; sin t +0.2 e – t v. 3-2. 155v.
3-3. 190ma.
3-4. 1.8倍.
3-5. 左供52w, 右供78w.
3-6. 1?; 1a; 0.75a.
3-7. 3a; 1.33ma; 1.5ma; 2/3a; 2a.
3-8. 20v, –75.38v.
3-9. –1a; 2a; 1a.
3-10. 5v, 20?; –2v, 4?.
3-12. 4.6?.
3-14. 10v, 5k?.
3-15.
3-16.22.5v
3-17. 4/3?, 75w; 4/3?, 4.69w.
3-18. 3?, 529/12w.; 1?, 2.25w.
3-19
3-20. 50?.
3-21. 0.2a.
3-22. 1a.
3-23. 1.6v.
3-24. 4a;
3-25. 23.6v; 5a,10v.
3-26.
3-27 4v
3-28. ※
第四章
4-1. 141.1v, 100v, 50hz, 0.02s,0o, –120o; 120 o. 4-2. 7.07/0 o a, 1/–45 o a, 18.75/–40.9 o a.
4-3., 7.75ma .
4-4. 10/53.13oa, 10/126.87oa, 10/–126.87oa,
10/–53.13oa;各瞬时表达式略。
4-5. 67.08v, 30v, 25v; 12v, 0, 12v, 0; 0, 0, 12v. 4-6. 7.07a; 10a, 50a.
4-7. 173.2?.
4-8. 4?, 1.5h.
4-9.11v
4-10. 5?, 0.1f.
4-11. 5a; 20/–53.13o?, 0.05/53.13o s.
4-12
4-13. 5?, 0.0577f; 3?, 29.33h;
3?,0.125f; 0?,0.02f
4-14.-z
4-15.
4-16. 10a, 141v.
4-17. 3.47?, 53.2?f.
4-18.
4-19. 26.3?, 78.8mh, 34.6?f.
4-20. 118.0v, 0.252?f.
4-21. 0.751?f .
4-23.
4-24. 10/0o a, 10/0o v, 200w,1; 20a, 0;5a.
4-25. 21.26a,1800w,0.846; 10.2?,2778w,0.926; 26.04
4-26. 495w, 0.375.
4-27.
4-28. 20 + j10?, 2.5w, 0.894.
4-29. 1.99?,31.99?或6.11?, 11?,–19.05?.
4-30. 30+j10=31.62/18.43o v, 300w, –300var.
4-31. a;2va, j2va,2va, –j2va, –4va.
4-32. 2/–90o a; 13.3/11.9o v, 7.97–j2.16?,
3.16/63.4o v, 1+j1?.
4-33.
4-34. 5a, 11.09a, 10.83a, 1066w.
4-35. .
4-36. 200/–150o ma.
4-37. 10h.
4-38. 5?, 27.57mh, 367.75?f.
4-39. 0.5?, 0.5h; 0.25w.
4-40. 1.86 + j0.56?, 8.10w.
4-41. 0.8 + j0.4?, 0.125w
4-42.
4-43. 100?, 0.667h, 0.167?f, 20..
4-44. 10?, 0.796mh, 3183pf; 50.
4-45. 0.1?f;
4-46. 0.02h, 50.
4-47. 100.5pf, 0.091v.
4-48. 25?f , 180v.
4-49. 0.253?f , 0.760?f .
4-50. 4.12a. f. ?
4-51.
4-52. 30.09(-65.8)a, 17.37(-35.8)a.
4-53. 2850w;1425w
4-54.4.84?
4-55. 9077w;7942w
4-56. (1) ia不变,因对称时中线不起作用。
(2) 仍不变,因为s闭合时各相负载电压未变,电流表所涉及的两个a相负载也未变。 4-57. 38/–53.13oa, 38/–66.87oa, 33.59/75oa; 64.41/–77.35oa; 9.09/–150.0oa; 67.68/95.29oa.
4-58. 190w, 380w.
4-59. 1kw.
4-60. 6.06a.
4-61. 871.2w, 1161.6var; 290.4w, –668.5var.
4-62. p(a) =p左 +p右 ; q(b) = pw .
4-63.可.
4-64. 0.1103h, 91.89?f.※
第五章
5-1.
5-2. 根据绘出.
5-3.
5-4. (b)读数大。
5-5. ,
5-6. 52.83mh.
5-7.
5-8. 20mh, 2.2v, 4.4v, 4.4v, 44ma, 22ma, 66ma.
5-9. 1.59/–12.7o a.
5-10. 13.42/–10.3o v; 1.69/–61.3o v.
5-11..
5-12. j0.75?.
5-13.
5-14. 50mh.
5-15. 20?h, 2.5w, 250v.
5-16. 4.06/–20.98o a, 0.406/–9.05o a, 8.903/–157.8o a.
5-17. 2kw, 3.2kw.
5-18. 0.09w; 3, 0.25w.
5-19. 1.414a.
5-20. u2 /u1 从3.356 降为0.0239.
5-21. 20 – j15?, 2.8125w.
5-22. 80.0w, –20.0w, 100w.
注意到pr1= 20w,pr2= 60w,可见:电源供给第2线圈共100w
的功率,其本身仅耗60w,其余40w经互感耦合至第1线圈,线圈
1耗20w,还剩20w送还给电源(p1=-20w) ? p =100-20 = 80w 。
【篇二:电路理论基础习题答案】
>第一章
1-1. (a)、(b)吸收10w;(c)、(d)发出10w. 1-2. –1a; –10v; –1a; –1-3. –0.5a; –6v; –15e–t 4mw.
2t w.
1-4. u =104
i ; u = -104
i ; u =2000i ; u = -104
i ;
1-8. 2?
f; 4?c; 0; 4?j. 1-9. 9.6v,0.192w, 1.152mj; 16v, 0, 36.2mj. 1-10. 1–e-10 ta , t 0 取s . 1-11. 3h, 6(1– t )2
j; 3mh, 6(1–1000 t ) 2 mj;
1-12. 0.4f, 0 .
1-13. 供12w; 吸40w;
吸2w; (2v)供26w, (5a)吸10w. 1-14. –40v, –1ma; –50v, –1ma;
50v, 1ma. 1-15. 0.5a,1w; 2a,4w; –1a, –2w; 1a,2w.
1-16. 10v,50w;50v,250w;–3v,–15w;2v,10w. 1-17. (a)2v;r耗
4/3w;us : –2/3w, is : 2w; (b) –3v; r耗3w; us : –2w, is :5w; (c)2v,–3v; r耗4w;3w;us :2w, is :5w; 1-18. 24v, 发72w; 3a, 吸
15w;
1-24. 14v. 1-25. –2.333v, 1.333a; 0.4v, 0.8a. 1-26. 12v, 2a, –48w; –6v, 3a, –54w .※
第二章
2-4. 400v;363.6v;i.
2-21. 15a, 11a, 17a. 2-23. 7v, 3a; 8v,1a. 2-24. 4v, 2.5v, 2v. 2-26. 60v. 2-27. 4.5v. 2-28. –18v.
2-29. 原构成无解的矛盾方程组; (改后)4v,10v. 2-30. 3.33 k?, 50 k?. 2-31. r3 (r1 +r2 ) is /r1 . 2-32. 可证明 i l =- us /r3 . 2-33. –2 ; 4 . 2-34. (us1 + us2 + us3 )/3 . ※
第三章
3-1. –1+9=8v; 6+9=15v; sin t +0.2 e – t v. 3-2. 155v. 3-3. 190ma. 3-4. 1.8倍.
3-5. 左供52w, 右供78w. 3-6. 1?; 1a; 0.75a.
3-7. 3a; 1.33ma; 1.5ma; 2/3a; 2a.
3-8. 20v, –75.38v.
3-9. –1a; 2a; –17.3ma. 3-10. 5v, 20?; –2v, 4?. 3-12. 4.6?. 3-13.
2v; 0.5a. 3-14. 10v, 5k?.
3-15. 4/3?, 75w; 4/3?, 4.69w. 3-16. 1?, 2.25w. 3-18. 50?. 3-19. 0.2a. 3-20. 1a. 3-21. 1.6v. 3-22. 4a; –2a.
3-23. 23.6v; 5a,10v. 3-24. 52v. ※
第四章
4-1. 141.1v, 100v, 50hz, 0.02s,0o, –120o; 120 o
.
4-2. 7.07 o– o.75– o
4-3. um3 , 7.75ma .
4-4. 10oa, 10oa, 10–o
10/–53.13o
a;各瞬时表达式略。 4-5. 67.08v, 30v, 25v; 12v, 0, 12v, 0; 0, 0, 12v. 4-6. 7.07a; 10a, 50a. 4-7. 173.2?. 4-8. 3.2?, 1.2h. 4-9. 5?, 0.1f. 4-10. 5a; 20/–53.13o?, 0.05/53.13o
s. 4-11. 52.34v. 4-12. 10a, 141v.
4-13. 5?, 0.0577f; 3?, 29.33h;3?,0.125f; 0?,0.02f 4-14. 3.47?, 53.2?f.
4-15. 0.3162cos(1000t?108.4?)a . 4-16. 26.3?, 78.8mh, 34.6?f. 4-17. 118.0v, 0.252?f. 4-18. 0.751?f . 4-19. 40.53pf.
4-20. 10/0o a, 10/0o
v, 200w,1; 20a, 0;2a. 4-21. 21.26a,1800w,0.846;
10.2?,2778w,0.926; 26.04?f. 4-22. 495w, 0.375.
4-23. 20 + j10?, 2.5w, 0.894.
4-24. 1.99?,31.99?或6.11?, 11?,–19.05?.
4-25. 30+j10=31.o
v, 300w, –300var. 4-26. 2cos(t?75?)a;2va, j2va,2va, –j2va, –
4va.4-27. 2–o a; 13.3o
v, 7.97–j2.16?,
3.16o
v, 1+j1?.
4-28. 近似为:j0.5v, 50 + j50?. 4-29. 5a, 11.09a, 10.83a, 1066w. 4-30. 1(?2?1?j6?).
4-31. 200–o
ma. 4-32. 10h.
4-33. 5?, 27.57mh, 367.75?f. 4-34. 0.5?, 0.5h; 0.25w. 4-35. 1.86 + j0.56?, 8.10w.
4-37. 100?, 0.667h, 0.167?f, 20.. 4-38. 10?, 0.796mh, 3183pf; 50. 4-39. 0.1?f; i?0.22cos5000t a;ul?4002cos(5000t?90?)v. 4-40. 0.02h, 50.
4-41. 100.5pf, 0.091v. 4-42. 25?f , 180v.
4-43. 0.253?f , 0.760?f . 4-44. 4.12a.
4-45. 1.174a, 376.5v. 4-46. 30.09a, 17.37a. 4-47. 54.05?f.
4-48. (1) ia不变,因对称时中线不起作用。
(2) 仍不变,因为s闭合时各相负载电压未变,电流表
所涉及的两个a相负载也未变。
4-49. 38–oa, 38–oa, 33.59o
64.41/–77.35oa; 9.09/–150.0oa; 67.68/95.29o
a. 4-50. 190w, 380w. 4-51. 1kw. 4-52. 6.06a.
4-53. 871.2w, 1161.6var; 290.4w, –668.5var. 4-54. p(a) =p左 +p 右 ; q(b) = 3pw .
4-55. 3e?a(z?3z1) , ze?a(z?3z1
) ; 可. 4-56. 0.1103h, 91.89?f.(4-57~4-58从略.) ※
第五章
5-1. cost v, ?0.25costv; 2sint v, 0.5sintv;
0.25e
?t
?2e?2t
v, 0.5e?2t
?0.25e?t
v. 5-2. 根据ud i1d i2d i121?4
d?
u1?
t
d t,
d2
d i t
?d绘出.
t
5-3. 152cos(2t?143.13o
) v. 5-4. (b)读数大。 5-5. 52.83mh. 5-6. 20mh, 2.2v, 4.4v, 4.4v, 44ma, 22ma, 66ma.
5-7. 1.59–o
5-8. 13.42–o .69–o
5-9. 1(2?mc) . 5-10. j0.75?. 5-11. 50mh.
5-12. 20?h, 2.5w, 250v.
5-13. 4.06–o , 0.406–o , 8.903–o
. 5-14. 2kw, 3.2kw.
5-15. 0.09w; 3, 0.25w. 5-16. 1.414a.
5-17. u2 /u1 从3.356 降为0.0239. 5-18. 20 – j15?, 2.8125w.
5-19. 80.0w, –20.0w, 100w.
注意到pr1= 20w,pr2= 60w,可见:电源供给第2线圈共100w
的功率,其本身仅耗60w,其余40w经互感耦合至第1线圈,线圈
1耗20w,还剩20w送还给电源(p1=-20w) ? p =100-20 = 80w 。 5-20. 9.09a,0.91a
5-21. nr1r2(ni1?i2)r1r2r;(ni1?i2)
1?nr2r1?nr2
,
500;0.1a.
5-23. 1.96nf,0.011h,0.0125w. 5-24. 40k?;2ma,4ma;2v,
4v.
5-25. 50pf,80pf,4?h;0.25a,0.125a,1.25w. 5-26. 107rad/s, 100; 80v, 40v; 50v, 50v, 20v, 40v. 5-27. 100pf,250pf,2.74?h .
※
第六章
6-1. (a) 非线性、定常、单向、流控;
(b) 线性、定常、双向、单调; (c) 非线性、定常、单向、单调;
(d) 非线性、时变、单向、cos2t≠0时单调(否
则流控);
(e)、(f) 非线性、定常、单向、单调;
(g) 线性、时变、双向、cos2t≠–1时单调(否则
压控); 6-2. 1.25?10
?5
即出现基波和三次谐波。 6-3. 3?, 11?; 0.5?, 0.25?. 6-4. 7.5mh,
2.5mh.
,v
t
6-8. (a) u = 2v ;(b) u = 6v ;
t?0, ?
1;(c)?
u??[0, 1], 当cost?0;
??
?(??, ?1], 当cost??1.6-9. 1.71v, 4.3a; 5.14a, 0.857a. 6-10.
10.83v或5.17v. 6-11. 1.34v, 1.16a,.
2.17a 6-12.
t
6-13. 2?19
cost v.6-14. 0.75h, 0.75h, 0.5f; 3h, 3h, 0.25f;
2 + 1.463?10?
3 cos(t–15.37?)v;
4 + 1.288?10?3 cos(t–38.20?)v. 6-15. 1 + (2/3)?10?3 cos628t a . 6-16. ?4un1?3(un1?un2)2
?3(uu2
?n1?n2)?
??3(u)2
n1?un23(u2
? n1?un2)?1?
6-17. –1v,2a .
6-18. 1v, 1.667a, 1.75a, 0.0833a;?1.875mv,
?9.375ma,?9.531ma,?0.1562ma . ※
第七章
7-1.
2um
?
4
1?3
?
?
t
7-3. um ? tt ,um ? t .
7-4. 122.9v, 10.97a;272.1w. 7-5. 89.6w
7-6. 100+20cos314 t +14cos(942 t +45o
)v;
101.5v, 10.15a, 1029.8w. 7-7. 87.25v, 1.69a, 1.80a.
7-8. 2cos(2 t +45o
)a, 3w.
7-9. 0.894cos(t–26.57o )+1.414cos(2t–45o
)a; 2.8w.
7-10. 30mh, 8.33?f, 36.9o
.
7-11. 5+5cos(?t–45o
)v. 7-12. 0.2533mh, 3.166?h. 7-13. 7.523mh, 31.86mh,
141cos?t+52.92 cos(3?t–60o
)v. 7-14. 700w. 7-15. 160v, 212.1v, 71.06v.
7-16. it-169.67o )+1.68cos(3?t–79.76o
b = 20.3cos(?)
+0.187 cos(5?t +36.64o
) a. 7-17. 101.8v; 223.3v, 220.7v; 382.2v, 223.3v. ※
第八章
8-1.d
uc
dt?10u dulrc?120 ;d
t?l(1?? )
u
l?0 ;
8-2. 6v,0.2a; 10v,10ma; -8v,2a; us /2;us /r. 8-3. (a) us /3, us /(3r), us /(3rc), 0; (b) 0, 0.05, 50000v/s, -1000a/s;
(c) 17v, 5a, 0, 4.5a/s; 8-4. 0, 0, us /l1 , 0. 8-5. 3.330a; 2v; -
10v,10v/s. 8-6.
4e
?2t
v, 40e
?2t
? a, t?0
;
3e
?111.1t
v, ?0.667e?111.1t
ma, t?0; -2.5e?5t
v, 0.5e
?5t
a, t?0
8-7. 10e
?666.7tv, t?0; 10e
?2t
v, t?0.
8-8. (a)2e?2t
a, -16e
?2tv, t?0. (b)2e?50ta, 6e
?50t
v, t?0.
8-9. 0.24(e?500t
?e?1000t
)a, t?0
?33333. 3t
)v, t?0;
12(1?e?0.1t
)v, t?0.
8-12. i??0.5?0.75e
?208.33t
ma, t?0
8-13. –39.3v, 4.192ma, 6.212ma.
8-14.i?6.325cos(?t?1.572t
?18.43?)?e
a, i1?4.472cos(?t?26.57?)?e
?1.572t
a,
i2?4.472cos(?t?18.43??1.572t
)?2e
a, t?0
8-15. (5?e?t
) v, t?0
8-16. (1)rc并, r =1.333k?, c =0.75?f;
(2) rl并, r =2k?, l =2h. 8-17.15e
?7.5t
v, t?0. 8-18. 4?, 4?, 0.25f; 2.5v, 0.
8-19. -10?20e?0.2tv, t?0; 3.466sec. 8-20. (a)4e?1.25?105 tv, t?0.
(b)-15?75e?t/9v,t?0. 8-21. 3?2.5e?12tv,t?0.
8-22. (1)5e?1.5ta, 103?53e?1.5tv, 10
3
(1?e?1.5t)v, t?0 (2) 25j, 0; (3)11.11j, 5.56j, 8.33j; 8-23. 0.582cos(7t?125?)?1.47e?10ta, t?0.
8-26. (1)f(?t1); (2)1.547;(3)f(t1)
8-28. ??120?67.5e?250tv, 0?t?0.1s
?150?38.6e?57.1(t?0.1)
v, t?0.1s. 8-29. ??u1?10-12e?tv,
?u2
?10?15e?tv, 0?t?10ms; ??u1?-5?5.84e?(t?10)v,
t?u?(t?10)?10ms. 2
8-31. (1)1-2e?t, t?0; (2)-e?t, t?0;
(3)3?e
?t
?52cos(t?
3?
4
), t?0. 8-32. (1)
1r2c
re?(r1?r2)tr1]?(t);
1?r[1?2
(2)
1e
?(r1?r2)tr1r2c
r?(t).
1r2c
8-33. 2
(1)
du
c?5duc
dt
2
6?518uc?4?(t) ; dt
3
d2(2)
i
l
?dildt
2
6?il??(t)?4?(t) .
dt183
8-34. p1,2??0.417?j0.323, 欠阻尼.
8-35. (a)临界阻尼; (b)过阻尼。
8-36. 60e?4t?40e?5tv; 12e?4t?10e?5t
v, t?0. 8-37. 3.36e
?0.92t
?2.36e
?1.31t
v, t?0
8-38. 1?1.414e?tcos(t?135?)a. 8-39. 2?3e?t ?e
?3t
a, t?0; 2-2(2t?1)e
?2ta, t?0. 8-40.1.631e
?2t
-1.892e
?4t
?0.434cos(t?
49.4?)v, t
?0.
8-41. 5?1500te
?200t
a, t?0.
8-42. 16cos8t v, t?0;
0.778e
?0.375t
sin0.2856t v, t?0.
(b)3?13
8-44. (a)3?(0.667?0.133e
?2.4t
?2.4t
(b)10?(4?2.4e
?t/1.5
?t/1.5
8-45. (1)(t?3)e?t?(t?3);
(2)(t?1)[?(t?1)??(t?2)].
8-46. (1?e?2t)?(t)?[1?e?2(t?1)]?(t?1) ?2[1?e
?2(t?2)
]?(t?2)?4e
?2(t?3)
?(t?3)a.
8-47. (15?10t
?10e?t
)?(t)?[15?10t?5e
?(t?1)
]?(t?1)v.8-48. (1)?2
3
e
?0.833
t
?(t);
(2)(0.96?0.8t?0.96e
?0.833
t
)?(t)
?[0.96?0.8t?0.16e
?0.833(t?1)
]?(t?1)v.
?duc
?3?
8-49. ?
??1
?dt
????2020??u0
c???
?di??? ???? u?s
. l?dt??3?6??55??i?l???
?5??duc?
8-50. ?
??dt
?????4?1??uc????dil?6?
??
??dt
???
?31?????4? us ?il????30??
?du?c??dt??0????c??
c
??u?
8-51. ??c??0? ?
dil1
????dt??r1
l0? ???????? u1l1???l1?s ??i?l1??dil2??r2???dt??0 ??l2
??il2???0?l2?
?uc?
uo??00r2? ?il1???0? u?s;
?il2??
8-52.
duc1??332u132u1dus
dtc1?s?2dt
;u0?us?uc1; ?duc1?
?dt?????
?0?
6??uc1?
?6? ?
du??6c2
??dt?????1120?1??1?3? ???uc???12? us, ?di??0 ?l
?1??2
?????dt??
??
2
?il????0??
?uc1?
uo??010? ?uc2???0? u?s.
?il??
?8-53.
?duc??????1
?
1
0??uc?
?dt??
r3
c
c?
?1? ?di1?r??2m
??
?rc? 3?dt??
l2
?r1l2??2
???
l1l2?mllm
2
2
? ??i1??
??12?l1l2?m?di2r???
?0? u
s1m?r2l1??i2?????
?m?
dt????l21l2?m
l21l2?m
l1l2?m
2
??
??
?0??
caa习题8-54、8-55、8-56从略。第九章 9-1rz. (a) ?
r1?r2
2????
r , (b)
2
r2??
z? ?
,
(c)
??2?j4
2?j2??
9-2. (a)?
?g
???
?g
r?
1? ?1
3
?
(c)
?4?3?s ;?5
?4??
??31.5?? (d)1
3?? ?4
5??
s .
1?;(b)
?0.01s?
??
.
(c)??1
0?0????1 ; (d)?1 1??
0???? 0
1? . ?
4?
?r1
3?
??4
j1s?;(b)??
?r1?. ??r2r?2?
(c)
?20??10?? ?10
0??
.
9-5. (a)t??1
0?? ; y不存在;
1??
(b)z?
2??
(c)t??n
0?n??
;?0; z和y不存在; ?0? 或h?? ???n
0??
(d)h?
?00?
; ?0
0?
?
1y不存在; ??; z和?
(e)t?
01
?
或h?
; ?
0?
; .
9-6. ?
5/3
178/3??1.667
?
?1/24
25/12????
?0.04167s2.0833? ?
9-7. (a)
见右图; a
21ub
s / y21
【篇三:电路理论基础2011秋参考答案 (1)】
:,请将其中唯一正确的答案填入括号中。
1.在题图1.1所示电路中,若已知i=0.2a,则us=()
a.9v
b.8v
c.-8v
d.-9v
u
题图1.1 题图1.2
2.如题图1.2所示电路中,若已知i=2/3a,则r=()。
a. 4?
b.5?
c.6?
d.7?
3.正弦rl串联电路,端电压与电流为关联参考方向,则其相位关系为()
a. 电流滞后电压角90?
b. 电流滞后电压某一小于90?的角度
c. 电流超前电压角90?
d. 电流超前电压某一小于90?的角度
4.已知图1.3所示电路中负载1和2的平均功率、功率因数分别为p1?80w、?1?0.8 (感性)和 p2?30w、?2?0.6 (容性)。负载1和2的无功功率分别为()。
a.
q1??60var,q2?40var
b.
q1?60var,q2?40var
c.
q1??60var,q2??40var
d.
q1?60var,q2??40var
5.图1.4所示电路的网络函数h(j?)?
uc
属于()。 u
a.转移电压比b.输入导纳 c.转移阻抗d.输入阻抗
?
?u?
c
图题1.3 图题1.4
6.对称三相电路线电压相同时,三角形联接的负载每相电压是星形联接的( )。 a.1/3 倍 b.3倍cd.
7.对电阻电路列写的标准形式节点法中,关于自导与互导的叙述正确的是()。
a .同为恒正 b. 同为恒负 c. 自导恒正、互导恒负d. 自导恒负、互
导恒正 8.感性负载两端电压为220v,流过电流为20a,消耗平均
功率为2200w,则其功率因数角为()。
a .-60度 b. 30度 c. -30度d. 60度
9.在正弦稳态电路中下列那个量一般是不守恒的()。
a .复功率 b. 有功功率 c. 无功功率d. 视在功率
10.
已知is?[2?2cos(?t?30)?2cos3?t?t?20)]a,其有效值为()。
a . 2a b. 3ac. 6ad. 9a
一、填充题:在下列各题中,请将题目所要求的解答填入各横线上方。
1、若已知某阻抗消耗的有功功率p为30w,无功功率q为40var,则其视在功率 s为a。
2、非正弦周期电流的有效值为
3、如题图2.1所示一端口网络n发
出的功率为w。
?
?
u
?
题图2.1
题图2.2
4、如题图2.2所示,电路处于正弦稳态中,u??t?60?)v,i??ta则该线性一端口网络n的功率因数 cos?? 。
5、如题图2.3所示有源二端网络的戴维南等效电路中电压源电压和
串联电阻值分别为 v;?。
题图2.3 题图2.4
6、写出下列向量所对应的正弦量或正弦量所对应的向量(设角频率为?) u?j5则i?10co?st(?
?
则; 3 0
7、电路如题图2.4所示,已知电压源吸收功率24 w,则电阻r为?, 所吸收的功率p为。
8、对称星形联结的电路中,在幅值上线电压等于相电压的前于先行
相电压。
9、我国电力系统所用的标准频率为,称为工频,相应的角频
率?rad/s. 10、串联等效电感等于各电感;串联等效电容等于各电容。