《电路分析基础》第2版-习题参考标准答案-2014-tjh 下载本文

《电路分析基础》各章习题参考答案

第1章 习题参考答案

1-1 (1) 50W;(2) 300 V、25V,200V、75 V; (3) R2=12.5Ω,R3=100Ω,R4=37.5Ω

1-2 VA=8.5V,Vm=6.5V,VB=0.5V,VC=?12V,VD=?19V,Vp=?21.5V,UAB=8V,UBC=12.5,

UDA=?27.5V

1-3 电源(产生功率):A、B元件;负载(吸收功率):C、D元件;电路满足功率平衡

条件。

1-4 (1) VA=100V,VB=99V,VC=97V,VD=7V,VE=5V,VF=1V,UAF=99V,UCE=92V,

UBE=94V,UBF=98V,UCA=?3 V;(2) VC=90V,VB=92V,VA=93V,VE=?2V,VF=?6V,VG=?7V,UAF=99V,UCE=92V,UBE=94V,UBF=98V,UCA=?3 V 1-5 I≈0.18A , 6度,2.7元 1-6 I=4A, I1=11A,I2=19A

1-7 (a) U=6V,(b) U=24 V,(c) R=5Ω,(d) I=23.5A

1-8 (1) i6=?1A; (2) u4=10V,u6=3 V; (3) P1 =?2W发出,P2 =6W吸收,P3 =16W吸收,

P4 =?10W发出,P5 =?7W发出, P6 =?3W发出 1-9 I=1A,US=134V,R≈7.8Ω 1-10 S断开:UAB=?4.8V,UAO=?12V,UBO=?7.2V;S闭合:UAB=?12V,UAO=?12V,UBO=0V 1-11 支路3,节点2,网孔2,回路3

1-12 节点电流方程:(A) I1 +I3?I6=0,(B)I6?I5?I7=0,(C)I5 +I4?I3=0

回路电压方程:①I6 R6+ US5 +I5 R5?US3 +I3 R3=0,②?I5 R5?US5+ I7R7?US4 =0,③?I3 R3+ US3 + US4 + I1 R2+ I1 R1 =0

1-13 UAB=11V, I2=0.5A,I3=4.5A, R3≈2.4Ω

1-14 VA=60V,VC=140V,VD=90V,UAC=?80V,UAD=?30V,UCD=50V 1-15 I1=?2A,I2=3A,I3=?5A,I4=7A,I5=2A

第2章 习题参考答案 2-1 2.4 Ω,5 A

2-2 (1) 4 V,2 V,1 V;(2) 40 mA,20 mA,10 mA 2-3 1.5 Ω,2 A,1/3 A 2-4 6 Ω,36 Ω 2-5 2 A,1 A 2-6 1 A 2-7 2 A 2-8 1 A

2-9 I1 = ?1.4 A,I2 = 1.6 A,I3 = 0.2 A

2-10 I1 = 0 A,I2 = ?3 A,P1 = 0 W,P2 = ?18 W

2-11 I1 = ?1 mA,I2 = ?2 mA,E3 = 10 V 2-12 I1 = 6 A,I2 = ?3 A,I3 = 3 A

2-13 I1 =2 A,I2 = 1A,I3 = 1 A,I4 =2 A,I5 = 1 A 2-14 Va = 12 V ,I1 = ?1 A,I2 = 2 A

2-15 Va = 6 V,I1 = 1.5 A,I2 = ?1 A,I3 = 0.5 A 2-16 Va = 15 V,I1 = ?1 A,I2 = 2 A,I3 = 3 A 2-17 I1 = ?1 A,I2 = 2 A

2-18 I1 = 1.5 A,I2 = ?1 A,I3 = 0.5 A

2-19 I1 = 0.8 A,I2 = ?0.75 A,I3 = 2 A,I4 = ?2.75 A,I5 = 1.55 A 2-20 I3 = 0.5 A

2-21 U0 = 2 V,R0 = 4 Ω,I0 = 0.1 A 2-22 I5 = ?1 A

2-23 (1) I5 = 0 A,Uab = 0 V;(2) I5 = 1 A,Uab = 11 V 2-24 IL = 2 A

2-25 IS =11 A,R0 = 2 Ω 2-26 18 Ω,?2 Ω,12 Ω 2-27 U=5 V 2-28 I =1 A 2-29 U=5 V 2-30 I =1 A

2-31 10 V,180 Ω

2-32 U0 = 9 V,R0 = 6 Ω,U=15 V

第3章 习题参考答案

3-1 50Hz,314rad/s,0.02s,141V,100V,120° 3-2 200V,141.4V

3-3 u=14.1sin (314t?60°) V 3-4 (1) ψu1?ψu2=120°;(2) ψ1=?90°,ψ2=?210°,ψu1?ψu2=120°(不变) 3-5 (1) U1?502?90?V,U2?502?0?V;

(2) u3=1002sin (ωt+45°)V,u4=1002sin (ωt+135°)V 3-6 (1) i1=14.1 sin (ωt+72°)A;(2) u2=300 sin (ωt-60°)V 3-7 错误:(1) ,(3),(4),(5) 3-8 (1) R;(2) L;(3) C;(4) R 3-9 i=2.82 sin (10t?30°) A,Q≈40 var 3-10 u=44.9sin (314t?135°) V,Q=3.18 var 3-11 (1) I=20A;(2) P=4.4kW

3-12 (1)I≈1.4A,I?1.4??30?A;(3)Q≈308 var,P=0W;(4) i≈0.98 sin (628t?30°) A 3-13 (1)I=9.67A,I?9.67?150?A,i=13.7 sin (314t+150°) A;(3)Q=2127.4 var,P=0W;

(4)IC=0A

3-14 (1)C=20.3μF;(2) IL=0.25A,IC=16A

第4章 习题参考答案

4-1 (a) Z?5?36.87??,Y?0.2??36.87?S;(b) Z?2.52??45??,Y?0.22?45?S 4-2 Y=(0.06-j0.08) S,R≈16.67 Ω,XL=12.5 Ω,L≈0.04 H 4-3 UR?60?0?V,UL?80?90?V,US?100?53.13?V 4-4 I?20??36.87?A

4-5 Z?1002?45??,I?1?0?A,UR?100?0?V,UL?125?90?V,UC?25??90?V 4-6 Y?0.252?45?S,U?42?0?V,IR?2?0?A,IL?0.22??90?A,IC?1.22?90?A

?4?5,AUS?100?90?V 4-7 I?1024-8 (a) 30 V;(b) 2.24 A 4-9 (a) 10 V;(b) 10 A 4-10 (a) 10 V;(b) 10 V 4-11 U=14.1 V

4-12 UL1 =15 V,UC2 =8 V,US =15.65 V

4-13 UX1 =100 V,U2 =600 V,X1=10 Ω,X2=20 Ω,X3=30 Ω

4-14 Z?202?45??,I?2??45?A,I1?2?0?A,I2?2??90?A,Uab?0V

4-15 (1)I?2A,ZRC?52?,Z?510?;(2)R?10?,XC?10? 4-16 P = 774.4 W,Q = 580.8 var,S = 968 V·A 4-17 I1 = 5 A,I2 = 4 A

4-18 I1 = 1 A,I2 = 2 A,I?5?26.565?A,S?44.72??26.565?V?A

4-19 Z?10?,I?1?90?A,UR2?52?135?V,P?10W 4-20 ω0 =5×106 rad/s,ρ = 1000 Ω,Q = 100,I = 2 mA,UR =20 mV,UL = UC = 2 V 4-21 ω0 =104 rad/s,ρ = 100 Ω,Q = 100,U = 10 V,IR = 1 mA,IL = IC = 100 mA 4-22 L1 = 1 H,L2 ≈ 0.33 H

第5章 习题参考答案

5-3 M = 35.5 mH

5-4 ω01 =1000 rad/s,ω02 =2236 rad/s 5-5 Z1 = j31.4 Ω,Z2 = j6.28 Ω 5-6 Zr = 3+7.5 Ω 5-7 M = 130 mH 5-8 I2?2?45?A 5-9 U1 = 44.8 V

5-10 M12 = 20 mH,I1 = 4 A 5-11 U2 = 220 V,I1 = 4 A 5-12 n = 1.9

5-13 N2 = 254匝,N3 = 72匝 5-14 n = 10,P2 = 31.25 mW