《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