《电路》理论基础习题答案

电路理论基础习题答案 第一章 1-24.l4V 1-1.(a)、(b吸收10w;(c)、(d)发出10W 1-25.-2.33V,1.333A;0.4V,0.8A 1-26.12V,2A,-48W,-6V,3A,-54W 1-3.-0.5A;-6V,-15eV,175c0s21A;3g 第二章 1. cos- 2t W 1-4.=10;=-101;u=200011-10 2-1.2.50,1.6R,8/39,0.5R;49;1.489 R/8,1.5g,1.2699,409,149 100 2-2.l1.11Q.89:12.59 3.1.618 -4.400V,363.6V,A=5A,电流表及滑线电阻损坏 2-6.5kQ 1-6.0.1A LA 2-7.0.759 2-8.10/3A,1.x-5V,,8V42,0.5A,30/ 2-9.1A,2,5V,29,2A;2A;2A,69 2-10.-75mA;-0.5A. 2-11.69;7.592,0,2.19 80|-- 2-12.49,1.59;2k9 2-13.5.333A:4.286A 4()ns 2-14(a)-1A,(b)-2A,吸20W 2-16.3A 1-8.2F;4C,0;4J 2-17.733V 1-9.9.6V,0.192W,1.152 2-18.86.76W 16V0,3.2mJ 2-19.1V,4W. 1-10.1-e-10A,t>0取s 2-20.64W p(W) 1-11.3H,6(1-t)2J;3mH 2-21.15A.1lA.17A. 6(1-10001)2mJ 2-23.7V,3A;8V,1A (s) 2-24.4V,2.5V,2V 1-12.0.4F.0 2-26.60V 1-13.供12W,吸40W 2-27.4.5V 吸2W,(2V)供26W,(5A)吸10W 28.-18V 1-14.-40V,-1mA;-50V,-1mA;50V,lmA 2-29.原构成无解的矛盾方程组;(改后4V10V 1-15.0.5A,Ww,2A,4W,-1A,-2W,1A,2W 2-30.3.33ks,50k 1-16.10V50w;0V,250W;-3V,-15W;2V,l0W 2-31.R3(R1+R2)s/R1 1-17.(a)2VR耗4/3W,Us:-2/3W,ls:2W, 2-32.可证明IL=-t/R3 (b )-3V, R FE 3W Us: -2W, Is: 5W 2-33.-2:4 (c)2V-3V R E 4W: 3W; Us: 2W, Is: 5W 2-34.(s1+s2+ls3)/3.※ 1-18.24V,发72W,3A,吸15W, 24V电压源:3A↓电流源或5/39电阻 第三章 1-19.0, US/RL, US: US/Ri, US/RI, -Us Rf/RI 3-1.-1+9=8V6+9=15 V: sin t+0.2e-V 1-20.6A,4A,2A,1A,4A;8V,-10V,18V 3-2.155V. 1-21.K打开:(a)0,0,0;(b)l0V,0,10V, 3-3.190mA. (c)10V,10V,0,K闭合:(a)0V,4V,6V 3-4.1.8倍 (b)4V4V,0,(c)4V0,4V, 3-5.左供52W,右供78W 1-22.2VTV:3.25V:2V 3-6.l;lA;0.75A 1-23.109 3-7.3A;1.33mA1.5mA;2/3A;2A

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; –15e –t V; 1.75cos2t A; 3Ω; 1.8cos2 2t 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, –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; 24V电压源; 3A↓电流源或 5/3Ω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. 10Ω. 1-24. 14V. 1-25. –2.333V, 1.333A; 0.4V, 0.8A. 1-26. 12V, 2A, –48W; –6V, 3A, –54W . ※ 第二章 2-1. 2.5Ω; 1.6R; 8/3Ω; 0.5R; 4Ω; 1.448Ω; . R/8; 1.5Ω; 1.269Ω; 40Ω; 14Ω. 2-2. 11.11Ω; 8Ω; 12.5Ω. 2-3. 1.618Ω. 2-4. 400V;363.6V;IA= . 5A, 电流表及滑线电阻损坏. 2-6. 5kΩ. 2-7. 0.75Ω. 2-8. 10/3A,1.2Ω;–5V,3Ω; 8V,4Ω; 0.5A,30/11Ω. 2-9. 1A,2Ω; 5V,2Ω; 2A; 2A; 2A,6Ω. 2-10. –75mA; –0.5A. 2-11. 6Ω; 7.5Ω; 0; 2.1Ω. 2-12. 4Ω; 1.5Ω; 2kΩ. 2-13. 5.333A; 4.286A. 2-14. (a) –1A↓; (b) –2A↓, 吸20W. 2-16. 3A. 2-17. 7.33V. 2-18. 86.76W. 2-19. 1V, 4W. 2-20. 64W. 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. A i 0 1 s 1 2 3 1-e - t t 0 t ms mA i 4 10 0 t ms mW p 4 100 2 25 i, A 0.4 .75 t 0 .25 1.25 ms -0.4 (d) u, V 80 0 10 -20 t, ms (f ) u, V 100 0 10 t, ms (e) p(W) 10 0 1 2 t(s) -10

3-8.20V,-75.38V 3.16634°V,1+jl 3-9-1A:2A:-17.3mA 4-28.近似为:0.5V,50+j50 3-10.5V,205;-2V,4s 4-29.5A,11.09A,10.83A,1066W. 3-12.465 430.1/(o2 3-13.2v:0.5A 4-31.200/-150°mA 3-14.10V,5kc 4-32.10H. 3-15.4/35,75W,4/3,4.69W 4-33.5,27.57mH,367.75/F 3-16.1c,2.25W 4-34.0.55,0.5H,0.25W 3-18.50 4-35.186+0.565,8.10W 3-19.0.2A. 4-37.100,0.667H,0.167AF,20 3-20.1A 4-38.105,0.796mH,3183pF;50 3-21.1.6V 4-39.0.1F;i=02√2cos000A 3-22.4A:-2A 400√2cos(5000+90°V 3-23.23.6V:5A.10V 4-40.0.02H.50 3-24.52V 4-41.100.5pF,0.091V 第四章 4-1.141.lV,100V,50Hz,0.02s0°,-120°,120 4-43.0.253F,0.760F 42.7.070°A,1/=45°A,18.75/-409°A 4-44.4.12A 4-3.Un/√3,7.75mA 4-45.1.174A,376.5V 4-46.30.09A.17.37A. 4-4.10/53.13°A,10/12687A,10/-12687°A, 10/-53.13°A:各瞬时表达式略。 4-47.54.05/F 448(1)IA不变,因对称时中线不起作用。 4-5.67.08V,30V,25V,12V,0,12V,0;0,0,12V (2)仍不变,因为S闭合时各相负载电压未变,电流表 4-6.7.07A:10A.50A 所涉及的两个A相负载也未变 4-7.173.25 449.38/-5313°A,38/-6687A,335975A 4-8.3.2c,1.2H 64.41/-77.35°A:9.09/-150.0°A;67.68/95 49.55,0.F 4-50.190W.380W 4-10.5A,20/-53.13°,0.05/5313°S 4-51.lkW. 4-11.52.34V 4-52.6.06A. 4-12.10A.141V 4-53.871.2W,1161.6var;290.4W,-668.5Var. 4-13.5,0.0577F;3s,29.33H 3c,0.125F;020.02F 4-54.P(=P左+P右;Qb)=√3Pw 4-14.3.475,53.21F 4553EA(z+3z1),ZEA/(Z+3z1);可 4-15.0.316√2co1000110849)A 4-56.0.1103H,9189F、(4-57~4-58从略)※ 4-16.26.3c,78.8mH,34.6F 第五章 4-17.118.0V,0.252/F 5-1. coStV-025 cos tV: 2sin tV.0.sin tV 4-18.0.751/F 0.25e--2eV,0.5e-2-025e-V 4-19.40.53pF 4-20.100°A,10/0°V,200w,1;20A,0;2A. 5-2.根据=4 绘出 4-21.2126A,1800W0.846;10.25,2778W,0.926;26.04F 4-22.495W,0.375 5-3.15√2cos(2t-143.13°)V 4-23.20+j105,2.5W,0.894 5-4.(b)读数大 -24.199,31.99或6.1l,1lg-19.05 4-25.30+j10=31.62/1843°V,300W,-300Var 5-6.20mH.2.2V4.4V,4.4V44mA.22mA.66mA 4-26.2cos(t+759A2WA,n2WA2VA,-2A,-4Ⅵ 5-7.1.59/-12.7A 4-27.2-90°A13.3/119V,7.97-2.16 5-8.13.42/-103V;1.69/-61V

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 ; 120o . 4-2. 7.07/0 o A, 1/–45 o A, 18.75/–40.9 o A. 4-3. U m 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. 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. 0.316 2 cos(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. 10/0 o A, 10/0 o 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=31.62/18.43o V, 300W, –300Var. 4-26. 2 cos(t + 75) A;2VA, j2VA,2VA, –j2VA, –4VA. 4-27. 2/–90o A; 13.3/11.9 o V, 7.97–j2.16, 3.16/63.4 o V, 1+j1. 4-28. 近似为：j0.5V, 50 + j50. 4-29. 5A, 11.09A, 10.83A, 1066W. 4-30. 1 ( 1 6 ) 2  − − j  . 4-31. 200/–150o 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 = 0.2 2 cos5000t A; u = 400 2 cos(5000t + 90)V. L 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/–53.13oA, 38/–66.87oA, 33.59/75oA; 64.41/–77.35oA; 9.09/–150.0oA; 67.68/95.29oA. 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) = 3 PW . 4-55. 3 ( 3 ), ( 3 ); EA Z + Z1 ZEA Z + Z1   可. 4-56. 0.1103H, 91.89F.(4-57~4-58 从略.) ※ 第五章 5-1. cost V, − 0.25costV; 2sin t V, 0.5sin tV; 0.25 2 V, 0.5 0.25 V. t 2t 2t t e e e e − − − − − − 5-2. 根据 t i t i u t i t i u d d 2 d d d d d d 4 1 2 1 1 2 1 , = + = + 绘出. 5-3. 15 2 cos(2 143.13 ) V. o t − 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/– 12.7 o A. 5-8. 13.42/– 10.3 o V; 1.69/– 61.3 o V

1/(2m√MC) 6-7. 5-10.0.75s 5-11.50mH 5-12.20/H,2.5W,250V 5-13.4.06-2098A,0.406∠-905A,8.9032-1578A 5-14.2kW3.2kW 6-8.(a)l=2V;(b)lu=6V 5-15.0.09W,3,0.25W =cost+(c0s1),当cost≠0,-1; 5-16.1.414A (e)a∈,当cost=0 5-17.U2/U1从3.356降为0.0239 ∈(0 l]当cost=-1 5-18.20-15s,2.8125W 5-19.80.0W,-20.0W,100w 6-9.1.7V,4.3A;5.14A,0.857A 5-20.9.09A,0.91A 6-10.10.83V或5.17V 5-21,R(ni +i2).R, R2 (n1 +12) 6-11.1.34V,1.16A R1+nR2’R 5-22.50√2/458V,500√2/458c;0.1A 5-23.1.96nF,0.011H,0.0125W 03T3T 5-24.40ks;2mA,4mA;2V,4V 6-13.2+- cost V 5-25.50pF,8OpF,4H;0.25A,0.l25A,1.25W 6-14.0.75H,0.75H,0.5F;3H,3H,0.25F; 5-26.107rad/s,100,80V,40V,50V,50V,20V,40V. 2+14633102co(-15.378)V, 5-27.100pF,250pF,2.74H.※ 4+1.28831023cos(-38.208)V 第六章 6-15.1+(2/3)31023cos628tA 6-1.(a)非线性、定常、单向、流控 4u,+3(uniun (b)线性、定常、双向、单调 6-16 (c)非线性、定常、单向、单调 3(un-un2)23(un1-l2)2 (d)非线性、时变、单向、cos21≠0时单调(否6-17-V,2A 则流控) 6-18.IV,1.667A,1.75A,0.0833A;61.875mV (e)、(f)非线性、定常、单向、单调 69375mA,69.531mA,60.1562mA.※ (g)线性、时变、双向、cos21≠-1时单调(否则 压控): 第七章 6-2.1.25×10-(3 coS ot+cos3o)V 7-1.m(l+sin ot 即出现基波和三次谐波 1x3 Cos 2ot 6-3.3s,1l;0.5,0.25 5mH,2.5mH. xsos4ot^5×7 cos 6o1-…) 6-5.↑ LA U V 7-2 E_ES 2丌 7-3.Un√△1/√T,Un△/T 7-4.1229V,10.97A;272.W 7-5.89.6W 7-6.100+20c0s314t+14cos(942t+45)V 101.5V.10.15A.10298W OEI U 7-7.87.25V1.69A.1.80A (f) 7-8.2c0s(2t+45)A,3W 6-6 7-9.0.894c0s(-26.57°)+1.414cs(2r-45°)A,28 7-10.30mH,8.334F,36.9° 7-11.5+5c0s(m-45°)V (c)

5-9. 1 (2 MC ) . 5-10. j0.75. 5-11. 50mH. 5-12. 20H, 2.5W, 250V. 5-13. 4.06/–20.98o A, 0.406/–9.05o A, 8.903/–157.8 o A. 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. 5-20. 9.09A，0.91A 5-21. 1 2 1 2 1 2 1 2 1 2 1 2 ( ) ; ( ) R nR R R ni i R nR R R ni i n + + + + 5-22. 50 2 /45 V，500 2 /45 ；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. 107 rad/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 (3cos cos 3 )V. 5  ωt + ωt − 即出现基波和三次谐波。 6-3. 3, 11; 0.5, 0.25. 6-4. 7.5mH, 2.5mH. 6-5. 6-6. 6-7. 6-8. (a) u = 2V ；(b) u = 6V ； (c)       − − = −  = = +  − ( , 1], cos 1. [0,1], cos 0; cos (cos ), cos 0, 1; t t t t t u 当 当 ε 当 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. 6-13. cos V. 9 1 2 + t 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.       − − − + + − − − 3( ) 3( ) 1 4 3( ) 3( ) 2 n1 n2 2 n1 n2 2 n1 n2 2 n1 n1 n2 u u u u u u u u u 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. ) ( cos6 5 7 1 cos 4 3 5 1 cos 2 1 3 1 sin 2 4 1 2 −  −  −  + − t t t t m U ω ω π ω ω  7-2. T k t k E E k ω ω π π 2 sin , 1 2 1 −  =  = 7-3. U t T , U t T . m  m  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, 36.9 o . 7-11. 5+5cos(t– 45o )V. I U 0 5V (a) I,A U,V 0 15 (b) – 0.15 I U 0 US (c) US/R I U 0 RIS (e) -IS 1 R1 I 0 E1 U (d) -E2 1 R2 I 0 US U (f) -RIS -IS i 0 2 u (c)' 1 –3 –2 –1 –1 i 0 1 u 3 (d)' 1 –2 –1 –1 i(mA) t 0 π 2π 1 0.5 (a) i(mA) t 0 π 2π 1.5 0.5 1 (b) 0 T –1 t –– 20 3T uo(V) 3 –– 10 3T ––– 20 11T ––– 20 19T –1

7-12.0.2533mH,3.166H 82.(1)5e-5A,+号e-V,(1-e-)V,t≥0 7-13.7.523mH,3l.86mH, (2)25J,0,(3)11.lJ,5.56J,8.33J, 141cosot+ 52.92 cos(3 o1-60o)V 8-23.0582cos(7t-129°)+14eA,t≥0 7-14.700W 8-24.(a)E(1)+E(t-1)-E(t-2)-E(t-3) 7-15.160V,212.1V,71.06V (b)t(1)-(t-1)e(t-1); 7-16.iB=20.3cos(可1-169.67°)+1.68c0s(301-79.76°) +0.187cos(5可1+3664)A (c).E(1)-2(1-1)(t-1)+2(t-2)(t-2) 7-17.101.8V;223.3V,220.7V,382.2V,223.3V.※ (d).(+1)(+1)-2(-1)e(-1)+(1-3)(t-3) 8-26.(1)f(-t1)(21.547:(3)f(1) 第八章 8-27.0.661(1-e-)e()V 81,+10=120.duyx×(-B)4=0, R 120+675e-V 010ms 8-4.0,0,Us/L1,0 u2=5+73e05V, 8-53.330A,2V,-10V,10V/s 8-30.0.5(1-e-)e(1)-0.5[l-e-(-2)](-2) 8-6 4e-V,40e-A,t≥0 8-31.(1)1-2e,t≥0,(2)-e,t≥0, 3e-1v.-0.667e (3)3+e-+5√2co(-3z) 2.5e-sV.0.5eA.t≥0 8-7.10e6V,t≥0,10eV,t≥0 8-32.(1)R+R2 D[1+e-(R1+R2)t/RIR2C (R1+R2)/R1R2C R,R2C E(o 8-9.0.24(e--e-100)A,t≥0 830+50C+最C=号c0 8-10.1.024kV,52.66MΩ;4588.4s;50kA,50Mw 8-11.9(1 V,t≥0 12(1 V,t≥0. 2+8+=30+40 8-12.i=-0.5+0.75e-2083mA.t≥0 834.P12=-0.417±10.323,欠阻尼 8-13.-39.3V,4.192mA,6.212mA 8-35.(a)临界阻尼:(b)过阻尼 8-14i=6.325c0s(xt-1843°)-e-13A 8-36.60e--40eVv;12e-10eV,t≥0. l1=4472c0(m1+26.57°)+e-15m2A 8-37.3.36e-09-2.36e-l3V,t≥0 i2=4472c0s(xt-1843°)-2eA,t≥0 8-38.1+1414e-cos(t+135°)A 8-15.(5-e-)/8V,t≥0 8-39.2-3e-+eA,t≥0, 8-16.(1)RC并,R=1.33k,C=0.75F 2-2(2t+)e-A,t≥0 (2)RL并,R=2ks,L=2H 8-40.1.631e-1.892e-+0434c0s(1+494°)V,t≥0. 8-17.15e-3V,t≥0 8-41.5+1500e-0A.t≥0 8-18.45,45,0.25F;2.5V,0. 8-42.16cos8tV,t≥0 8-19.-10+20eV,t≥0;3.46 0.778e3sn02856V,t≥0. 820.(a)4e-125V,t≥0 8-43.(a)10-(5+e-)(1)A12()+12e()V (b)-15+7se-"V,t≥0 (b3-(-e3)()A:()-0.5e-a(V 8-21.3-2.5eV,t≥0

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. iB = 20.3cos( t-169.67o )+1.68cos(3 t–79.76o ) +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. 0; d (1 ) d 10 120; d d = − + = + L L C C u L R t u u t u  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. 4 V, 40 A, 0 2 2  − − e e t t t  ; 3 V, 0.667 mA, 0 111.1 111.1 −  − − e e t t t ; - 2.5 V, 0.5 A, 0 5 5  − − e e t t t 8-7. 10 V, 0; 10 V, 0 666 7 2   − − e t e t . t t . 8-8. (a) 2 A, -16 V, 0 2 2  − − e e t t t . (b) 2 A, 6 V, 0 50 50  − − e e t t t . 8-9. 0.24( )A, 0 500 1000 −  − − e e t t t 8-10. 1.024kV; 52.66MΩ; 4588.4s; 50kA; 50MW. 8-11. 9(1 )V, 0 33333.3 −  − e t t ; 12(1 )V, 0 0.1 −  − e t t . 8-12. 0.5 0.75 mA, 0 208.33 = − +  − i e t t 8-13. –39.3V, 4.192mA, 6.212mA. 8-14. 6.325cos( 18.43 ) A, 1.572t i t e − =  −  − 4.472cos( 26.57 ) A, 1.572 1 t i t e − =  +  + 4.472cos( 18.43 ) 2 A, 0 1.572 2 = −  −  − i t e t t  8-15. (5 − ) 8 V,  0 − e t t 8-16. (1)RC 并, R =1.333k, C =0.75F; (2) RL 并, R =2k, L =2H. 8-17. 15 V, 0 7.5  − e t t . 8-18. 4, 4, 0.25F; 2.5V, 0. 8-19. -10 20 V, 0 0.2 +  − e t t ; 3.466sec. 8-20. (a) 4 V, 0 5 1.25 10  −  e t t . (b) -15 75 V, 0 / 9 +  − e t t . 8-21. 3 2.5 V, 0 12 −  − e t t . 8-22. (1) 5 A, V, (1 )V, 0 1.5 3 1.5 10 3 5 3 1.5 10 + −  − − − e e e t t t t (2) 25J, 0; (3)11.11J, 5.56J, 8.33J; 8-23. 0 10 0.58 2 cos(7 −125) +1.47 A,  − t e t t . 8-24. (a).ε(t) +ε(t −1) −ε(t − 2) −ε(t − 3); (b).tε(t) − (t −1)ε(t −1); (c).ε(t) − 2(t − 1))ε(t − 1) + 2(t − 2)ε(t − 2); (d).(t + 1ε) (t + 1) − 2(t − 1ε) (t − 1) + (t − 3ε) (t − 3). 8-26. (1) ( );(2)1.547;(3) ( ) 1 1 f −t f t 8-27. 0.661(1 ) ( ) V 0.476 e t − − t ε . 8-28.    −  +   − − − 150 38.6 V, 0.1s 120 67.5 V, 0 0.1s 57.1( 0.1) 250 e t e t t t . 8-29.      = − = − − 0 10ms u 10 15 V, u 10 -12 V, 15 2 15 1 t e e t t ;     = + = + − − − − 10ms u -5 7.3 V, u -5 5.84 V, ( 10) 15 2 ( 10) 15 1 t e e t t . 8-30. 0.5(1 ) ( ) 0.5[1 ] ( 2) ( 2) − − − − − − − e t e t t ε t ε . 8-31. (1)1- 2 ,  0; (2) - ,  0; − − e t e t t t (3)3 5 2 cos( ), 0. 4 3 + + −  − e t t t  8-32. (1) [1 ] ( ); 1 2 1 2 1 2 1 (R R ) R R e t t C R R  − + + + (2) ( ). 1 2 1 2 1 2 1 (R R ) R R e t t C R R C  − + 8-33. (1) (t) ; 3 4 18 5 6 5 2 2 + + C =  C u dt du dt d uC (2) (t) 4 (t) . 3 2 18 5 6 5 2 2 + + L =  +  L i dt di dt L d i 8-34. p1,2 = −0.417  j0.323 , 欠阻尼. 8-35. (a)临界阻尼； (b)过阻尼。 8-36. 60 40 V; 12 10 V, 0. 4 5 4 5 − −  − − − − e e e e t t t t t 8-37. 3.36 2.36 V, 0 0.92 1.31 −  − − e e t t t 8-38. 1+1.414 cos( +135)A. − e t t 8-39. 2 3 A, 0; 3 − +  − − e e t t t 2 - 2(2t 1) A, 0. 2 +  − e t t 8-40. 1.631 -1.892 0.434 cos( 49.4 )V, 0. 2 4 + +   − − e e t t t t 8-41. 5 1500 A, 0. 200 +  − te t t 8-42. 16cos8t V, t  0; 0.778 sin 0.2856 V, 0. 0.375  − e t t t 8-43.(a)10 (5 ) ( )A;12 ( ) 12 ( )V. 4 4 e t t e t − t ε − εt − + δ + (1 ) ( )A; ( ) 0.5 ( )V. 3 1 (b)3 1.5 1.5 e t t e t − t ε − εt − − δ −

8-44(a)3-(0.667+0.133e24)(r)V 8-53. 06()-[2+0.16e241](1)A R.M (b)0-(4-24e-13)()V; -048(1)-048e-15c(1)A La」Lz2-M=ML-M 8-45.(1)(t-3)e-(t-3), CAA习题8-54、8-55、8-56从略。 (2)(t-1)[(t-1)-E(t-2) 8-46.(1-e-2)(1)+[1l-e-2(-)=(t-1) 第九章 2[1-e-2(=2)1(t-2)+4e23)(t-3)A 91(a)+是B,、()(+8z R, R2 + B)Z 8-47.(15-101-10e-)k()+[us-1+5e-)(t-1)V 2+j2-2-j4 8-48.(1)-3e083(1) j2 (20.96-0.8-0.968)() 9-2.(a [0.96-08-0.16 「4-31 d dt 31.5 +j0.5j50 9-3.(a) 0.01S (b) dt di 0-1 +j49 R10 dt iIS 鸡2 8-51 dt4 L 09-10 dt L 9-5.(a)T 不存在; d=立++4=(07/M/%下全耦合时Y不存在 (b)Z 0或H=(n Z和Y不存在; 00或T=0 00 Z和Y不存在; aL 0 e)T z不存在 dt 或H=0 6 5/3178/3 166759339 n=010]ae2|+回 l/2425/12004167S20833 9-7(a)见右图 -ho a b

8-44. 0.6 ( ) [2 0.16 ] ( )A. (a)3 (0.667 0.133 ) ( )V; 2.4 2.4 t e t e t t t ε ε − − − − + − + δ 0.48 ( ) 0.48 ( )A. (b)10 (4 2.4 ) ( )V; 1.5 1.5 t e t e t t t ε ε / / − − − − − − δ 8-45. (1)( − 3) ( − 3); − t e t t  (2)(t −1)[ (t −1) −  (t − 2)]. 8-46. (1 ) ( ) [1 ] ( 1) 2 2( 1) − + − − − − − e t e t t t   2[1 ] ( 2) 4 ( 3) 2( 2) 2( 3) − − − + − − − − − e t e t t t   A. 8-47. (15 10 10 ) ( ) [15 10 5 ] ( 1)V. ( 1) − − − − − − − t e t + t + e t t t   8-48. (1) ( ); 0.833 3 2 e t t  − − (2)(0.96 0.8 0.96 ) ( ) 0.833 t e t t  − − − [0.96 0.8 0.16 ] ( 1)V 0.833( 1) − − − − − − t e t t  . 8-49. S 5 1 0 5 6 5 3 20 3 20 1 u i u dt di dt du L C L C         +                − − − =           . 8-50. S 30 4 1 31 6 1 4 1 u i u dt di dt du L C L C         − +                 − − − =           8-51. S 1 2 1 2 2 2 1 1 1 2 1 0 1 0 0 1 0 1 1 1 0 u L i i u L R L L R L C C dt di dt di dt du L L C L L C           + −                             − − − − =                     S 2 0 0 2 1 0 u i i u R L L C O u +         = ; 8-52. 0 S 1 S 1 S 1 ; 2 1 32 1 32 3 C C C u u u dt du u u dt du = − + + = − ; S 2 1 2 1 0 12 1 6 1 1 2 1 0 3 1 0 12 1 6 1 0 6 1 u i u u dt di dt du dt du L C C L C C               +                         − − − − =                 ,     2 S 1 0 1 0 0 u i u u L C C O u +         = . 8-53. S 3 2 1 2 1 2 2 1 2 1 2 1 2 1 2 2 1 2 2 2 1 2 1 2 2 1 2 2 3 2 1 0 0 1 0 1 1 u R C i i u L L M R L L L M R M L L M M L L M R M L L M R L L L M L R C C dt di dt di dt du C C             +                                 − − − − − − − − − − − =                   CAA 习题 8-54、8-55、8-56 从略。 第九章 9-1 . Ω .                   − − + + − − + + + 2 4 2 2 2 2 2 4 (1 ) (1 ) (c) (a) , (b) , 2 2 1 2 2 j j j j Z Z Z Z R R R R R β β 9-2.   1 3 1 1 3 (a) ; (b) 2 1 − − − + + −     G G j C R G j C G ω ω S. 3 1 (c) S; (d) 4 5 5 4 3 1.5 4 3             − − − − 9-3. . 1 1 2 2 2 (2 ) ; (b) 0.01S 1 1 0.5 50 (a)           + − − − ω ω ω ω ω j j j j Ω . 0 1 0 ; (d) 0 1 1 0 (c) 1 1             − − − 9-4. . 2 2 1 1 0 ; (b) 4 1S 12 4 4 3 1 (a)         −       − + R R r R m j j Ω (c) . 10 0 20 10        − 9-5. (a) ; ; 1 1 0 T  Y不存在      = jωC (e) ; ; . (d) ; ; ; (c) ; ; ; (b) ; ; 0 1 1 0 1 1 1 0 0 0 0 0 0 0 0 1 0 0 . 2 1 或 不存在 或 和 不存在 或 和 不存在 全耦合时 不存在 T H Z H T Z Y T H Z Y Z Y       =       =         =       =       =       =       = − − − − − j L j L n n n n j M j L j L j M ω ω ω ω ω ω β β 9-6.       =      0.04167S 2.0833 1.667 59.33 1 2 25 1 5 3 1 3 Ω / 4 / 2 / 78/ 9-7. (a)见右图； + U · 2 OC = -Y21U · S / Y21 - a b Z2i = 1/Y22

b)Uoc =Z2,Is 9-17.-2.5e-10V,t>0 221=22,等效电路从略 9-18.10V,-0.5A 9-19.10+12cos3oA,3.36A z2121 dU2=ZIs+Z22I2i /ngR I/ng1 8(Z,+Z2+322)1/ +Z 50 9-22 J@Cr-+z 1+JOCZL 低通 S Q值低一些的带通。※ 11 8Q 12 43」U12025ob 0.59 第十章 102W 0-1.(1)N11+N2l2(2)N1-N2 (3)N11++N2l2 9-10. (4)H( 23么s B1)铁>B 10-2.(1)相等:(2)B相等,Ha)>Hlb) l2 (3)5Hd均不变:B、B与地均基本 不变;Ha明显下降 U1 3s Is[ U2 10-3.()i2-h;(2)主要在气隙中。 10-4.(1)18.55mA:(2)0.423A (3)2.65Acm,60.4A/cm;(4)0.685A l1 (5)2.65A/cm,6664A/cm 10-5.1764A 3S 1S 10-6 2U1 10-7.(1)4058mA;(2)3026N;(3)2354N 10-10.653W,15957.38c000455,0.0162S l1l.12.5W,337.5W,13.5c1428 10-11.9.92A,1.27A,0.324S,0.252S。※ 9-12.-1/29 1-5(wCR)+jwCR(6-WCR)R(3-WCR+J4OCR 402CR+jaC(3-W2CR2) 1-0CR+ S-43/18 15-13 jωC 9-16.4,5493Np;6A,0.0988A

(d) . (c) , , . (b) ; 2 21 S 22 2 2OC 2i 2 2 2OC 2i 2 11 21 12 S 22 11 21 2i 22 2OC 21 S U Z I Z I U Z I U I U Z I Z Z U Z I Z Z Z Z Z Z            = + + +       + − = =   等效电路从略 9-8. (a) (b) 9-9. . 4S 3 11 8        1.02W . 9-10. S. 0.2 0.2 0.8 1.7       − − 9-11. 9-12. –1/29 ; . 4 (3 ) 1 3 1 5( ) (6 ) (3 4 ) 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2       − + − − + − + − − + C R j C C R C R j CR CR j CR C R R C R j CR ω ω ω ω ω ω ω ω ω ω 9-13. ; 3S 2 5 3        , 2S 2.389 26 30.556 2S 43 18 26 275 9       − − − − =      − − − − Ω Ω / / . [ 3 (1 )] 1 2 1 3 2 2 2       + − − − − + ω ω ω ω ω ω ω j / j 9-14. S; . 1 2 13 15 15 13 14 1                  +  − −  − −  + − − L j C M j C M j C L j C ω ω ω ω 9-15. L C, L C. 9-16. 4 , 5.493Np ; 6A , 0.0988A . 9-17. –2.5e –10 t V，t > 0 . 9-18. 10V, –0.5A . 9-19. 2 cos3 A 7 1 3 10 + t ，3.336A . 9-20. jr 2n 2C . 9-21.       0 1 1 ng /ngR /ng ,             + + + 3 3 2 3 1 2 1 2 1 (1 ) ( ) 1 Z gZ Z g ng Z Z Z g Z Z / . 9-22. L L 2 1 j CZ j Cr Z ω ω + + . 9-23. 2 2 2 2 s + s + , 低通； 2 2 2 s + s + s , 带通； 4 2 2 s + s + s , Q 值低一些的带通。 ※ 第十章 10-1. (4) . (3) ; (1) ; (2) ; (1) (3) (1) (3) 1 1 2 2 1 1 2 2 1 1 2 2 H 铁 H 铁 B 铁 B 铁 N i N i N i N i N i N i    + + + − 10-2. (1)相等；(2)B 相等，H(a) > H(b) ； (3)   l H dl 均不变；B(a)、B(b) 与 H(b)均基本 不变；H(a)明显下降。 10-3. (1) i2 – i1 ；(2) 主要在气隙中。 10-4. (1)18.55mA； (2)0.423A； (3)2.65A/cm，60.4A/cm；(4)0.685A； (5)2.65A/cm，6664A/cm。 10-5. 176.4A。 10-6. 2622.5A，0.656A。 10-7. (1)4058mA；(2)302.6N；(3)235.4N。 10-8. 2.888A。 10-9. 约 200 匝。 10-10. 63W, 15.9, 57.38, 0.00445S，0.0162S。 10-11. 12.5W，337.5W, 13.5, 14.28。 10-11. 9.92A，1.27A , 0.324S, 0.252S。 ※ 12.5  50 ７  50 ７ 4 2 2 2.5Ω 0.5Ω 0.25Ω + U2 - I 2 + U1 - I 1 1.7S -0.9S -1.5S 1.5U1 + U1 - 1S I2 + U2 - + U1 - I1 2S 3S 1S I2 + U2 - + U1 - I1 2S 3S 2U1 20S I2 + U2 - + U1 - I1 10S 5U1