电路理论基础习题答案.doc

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; 4mW.1-3. 0.5A; 6V; 15et V; 1.75cos2t A; 3; 1.8cos22t W.1-4. u =104 i ; u = -104 i ; u =2000i ; u = -104 i ;0tms pmW41002250tmsimA4101-5.i, A0.4 .75 t 0 .25 1.25ms-0.4(d)1-6. 0.1A.1-7. u, V1000 10 t, ms(e) u, V 80 0 10 -20 t, ms(f)iA0ms11231-e-tt1-8. 2mF; 4mC; 0; 4mJ.1-9. 9.6V,0.192W, 1.152mJ; 16V, 0, 3.2mJ. p(W) 10012t(s)-101-10. 1 e-106 tA , t 0 取s .1-11. 3H, 6(1 t )2 J; 3mH, 6(11000 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; 24V6电压源; 3A电流源或5/3电阻.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.1-23. 10.1-24. 14V.1-25. 2.333V, 1.333A; 0.4V, 0.8A. 1-26. 80V. 第二章2-1. 2.5; 1.6R; 8/3; 0.5R; 4; 1.448; .R/8; 1.5; 1.269; 40; 14.2-2. ,.2-3. 1.618.2-4. 400V;363.6V;IA=.5A, 电流表及滑线电阻损坏.2-6. 5k.2-7. 0.75.2-8.R1=38K,R2=10/3K2-9. 10/3A,1.2;5V,3; 8V,4; 0.5A,30/11.2-10. 1A,2; 5V,2; 2A; 2A; 2A,6.2-11. 75mA; 0.5A.2-12. 6; 7.5; 0; 2.1.2-13. 4; 1.5; 2k.2-14.1.6V,-24V2-15. (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1050W2-232-24. 7V, 3A; 8V,1A.2-25. 4V, 2.5V, 2V.2-26.22-27. 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.2-312-32.2.5A2-33. 3.33 kV, 50 kV.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. 1V; 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, 20V; 2V, 4V.3-12. 4.6V.3-13. 2V; 0.5A.3-14. 10V, 5kV.3-15.3-16.22.5V3-17. 4/3V, 75W; 4/3V, 4.69W.3-18. 3V, 529/12W.; 1V, 2.25W.3-193-20. 50V.3-21. 0.2A.3-22. 1A.3-23. 1.6V.3-24. 4A; 3-25. 23.6V; 5A,10V.3-26.3-27 4V3-28. 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. 173.2V.4-8. 4V, 1.5H.4-9.11V4-10. 5V, 0.1F.4-11. 5A; 20/53.13oV, 0.05/53.13o S.4-124-13. 5V, 0.0577F; 3V, 29.33H; 3V,0.125F; 0V,0.02F4-14.-Z4-15.4-16. 10A, 141V.4-17. 3.47V, 53.2mF.4-18. 4-19. 26.3V, 78.8mH, 34.6mF.4-20. 118.0V, 0.252mF.4-21. 0.751mF .4-22. 40.53pF.4-23.4-24. 10/0o A, 10/0o V, 200W,1; 20A, 0；5A.4-25. 21.26A,1800W,0.846; 10.2V,2778W,0.926; 26.04mF.4-26. 495W, 0.375.4-27.4-28. 20 + j10V, 2.5W, 0.894.4-29. 1.99V,31.99V或6.11V, 11V,19.05V.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, 7.97j2.16V, 3.16/63.4o V, 1+j1V.4-33.4-34. 5A, 11.09A, 10.83A, 1066W.4-35. .4-36. 200/150o mA.4-37. 10H.4-38. 5V, 27.57mH, 367.75mF.4-39. 0.5V, 0.5H; 0.25W.4-40. 1.86 + j0.56V, 8.10W.4-41. 0.8 + j0.4V, 0.125W4-42.4-43. 100V, 0.667H, 0.167mF, 20.4-44. 10V, 0.796mH, 3183pF; 50.4-45. 0.1mF; 4-46. 0.02H, 50.4-47. 100.5pF, 0.091V.4-48. 25mF , 180V.4-49. 0.253mF , 0.760mF .4-50. 4.12A.4-51.4-52. 30.09(-65.8)A, 17.37(-35.8)A.4-53. 2850W;1425W4-54.4.84V4-55. 9077W;7942W4-56. (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, 91.89mF. 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. j0.75V.5-13.5-14. 50mH.5-15. 20mH, 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 j15V, 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 =10020 = 80W 。5-23. 9.09A，0.91A5-24. 5-25. 50/458 V，500/458 V；0.1A.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、cos2t0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、cos2t1时单调(否则压控)；6-2. 即出现基波和三次谐波。6-3. 3V, 11V; 0.5V, 0.25V.6-4. 7.5mH, 2.5mH.IU0 RIS(C)-ISIU0 US(B)US/RI,AU,V0 15(A) 0.156-5. iu02(c)13211iu013(d)12116-6. 6-7. (a) u = 2V ；(b) u = 6V ；(c) 6-8. 1.71V, 4.3A; 5.14A, 0.857A.6-9. 10.83V或5.17V.6-10. 1.34V, 1.16A,.0T1 t203Tuo(V)3103T2011T2019T12.17A6-116-12 3.53mA 6-13.6-14. 6-15. 6-16. 0.75H, 0.75H, 0.5F; 3H, 3H, 0.25F; 2 + 1.46331023 cos(t15.378)V;4 + 1.28831023 cos(t38.208)V.6-17. 1 + (2/3)31023 cos628t A .6-18. 6-19. 1V，2A .6-20. 1V, 1.667A, 1.75A, 0.0833A;61.875mV,69.375mA,69.531mA,60.1562mA . 第七章7-1. 7-2. 7-3. 7-4. 122.9V, 10.97A；272.1W.7-5. 89.6W7-6. 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(t26.57o )+1.414cos(2t45o )A; 2.8W.7-10. 30mH, 8.33mF, 36.9o.7-11. 5+5cos(vt45o )V.7-12. 0.2533mH, 3.166mH.7-13. 7.523mH, 31.86mH, 141cosvt+52.92 cos(3vt60o)V.714 112.5W7-15. 700W.716. A;15W7-17. 160V, 212.1V, 71.06V.7-18. 80.5W7-19. iB = 20.3cos(vt-169.67o )+1.68cos(3vt79.76o ) +0.187 cos(5vt +36.64o ) A.7-20. 101.8V; 223.3V, 220.7V; 382.2V, 223.3V. 第八章8-1.8-2. 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.; ;8-7. .8-8. (a).(b).8-9. 8-10. 1.024kV; 52.66M; 4588.4s; 50kA; 50MW.8-11. ;.8-12. 8-13. 39.3V, 4.192mA, 6.212mA.8-14.8-15. 8-16. (1)RC并, R =1.333kV, C =0.75mF;(2) RL并, R =2kV, L =2H.8-17.8-18.8-19. 4V, 4V, 0.25F; 2.5V, 0.8-20. ; 3.466sec.8-218-22. (a).(b).8-23.（t0）8-24. (1)(2) 25J, 0; (3)11.11J, 5.56J, 8.33J;8-258-26. .8-278-28.8-298-30. 8-31. .8-32. .8-33. ;.8-34. .8-358-36. 8-378-38. 8-39. 8-40. , 欠阻尼.8-41. (a)临界阻尼； (b)过阻尼。8-42. 8-43. 8-44. 8-45. 8-46.8-47. 8-48. 8-49.8-50. 8-51. 8-52. A.8-53. 8-54. .8-55. .8-56. 8-57. ;8-58. ;,.8-59. 第十章10-1. 10-2. 10-3. 10-4. 10-5. + U 2OC = -Y21U S / Y21-abZ2i = 1/Y2210-6. 10-7. (a)见右图；12.5VV50V5010-8. (a)4V2V2V(b)10-9.0.52.50.25+U2-I2+U1-I110-10. 1.02W .1.7S-0.9S-1.5S1.5U1+U1-10-11. 1SI2 +U2