电工电子学课后习题集规范标准答案

1、电工电子学课后习题答案电工电子学课后习题答案第一章电路的基本概念、定律与分析方法练习与思考习题第二章正弦交流电1414第三章电路的暂态分析29第四章常用半导体器件41第五章基本放大电路43第六章集成运算放大器及其应用46第七章数字集成电路及其应用54第八章Multisim简介及其应用65课后习题65第九章波形的产生与变换67第十章数据采集系统第十一章直流稳压电源69第十二章变压器与电动机71第十三章电气控制技术77第十四章电力电子技术80第一章电路的基本概念、定律与分析方法练习与思考1.4.2（ b）36V42V6Q6V1.4.2(c)0Ct丄L t6 5 Q1 ©2Ao1.4.3

2、(a)*+ =UabRab5Q丿40VY a±5 5 2 15/1.4.3 (b)Uab 66642V5Q15VQaQbR 6ab1.4.3 (c)5Q)40V10 40/Uab Ur 10 6 5Rab 51.4.3 (d)3Q+)6VUs14Us2 KVL:2 1UabUab3 2坐VRab1.4.4 (2)bR2R4R3Ri15K 6乂 5V： J 5/0R215 Vb15 Vb42R215 VbR45 VbR3RiKCL: 1J求方程中Vb4VbR2VbR4KCLVb =R2V±50kVb50kVb100kVbVbR3Vb+9 = Vb +9r1100k1VKVL6

3、50KI+100KI9=0x1100KI=15 I=Vb =650k(a)x5 4(b)x10.4x20.30.230x40.20.10.3A0.30.60.9A27A0.7(C)x3x20.2 0.20.1A0.019.610.30.310.31A9.3AA10k=1V10k习题0.3A1.360.5 9.39.6A101.31428发出功率P21 10吸收功率P3吸收功率P410)10吸收功率P发=28F吸 =28P发=PfeR650mv120Q(a)U R'6(b) u1.7(a)Us14 4v(b)Is2A5 Us1.8Us12 21014V10Is221A10P2 1428P

4、2101101.612R1.92 2604V60 1200 Us 9VI10.45A0.3A I3Rx0.45 0.30.15AU123竺二 168Q0.15(a)：U2 U116VRy101.10(b)：U2(c)：U2(d)：U2545554555161.6V1.60.16VO.16 455 0.016V1.11U21R2 RpU1RR2Rp8.417U22U1aR2R2Rp5.64V1.12Rcd6 3Rbd=0.5QRad 1990.5Q0.5 199.氐I110I35 mA 125 mAI43.60.63.64.2mA0.8mA10 199.5UADUbd=1 5=5mVPS10 1

5、.9951.995mV0.019951.13 (a)(b)R22AD5a92Q节10V3Q丿15V6Q厂)12V+1.15JOA4AT T9QO 3V3Q3Q3 Q3n3 Q6V* 01A J.5 Q 广1.5 Q 3 Q+()1.5VI 1A132Q11I 01210 1010Is121I4I55I30266 336 3 1A 3 21 1 02A1A2 -A31a31.17丄J丄JI丄1|2Ar76Q2Q4A©2Q 2V + J丿8心出2QI -821.18II I2KVL:I3U1I1 R|13R30I11675I2675I322751.19I1 18I3 I2KVL :140

6、 20li 6I20I3 6I20I14A I210A I312Au120I180V6I2U2电压源P60V140560发出功率电流源P6018108发出功率1.20I1 I2+10KVL :0.8I11201160.4120.412 116 4I20I18.75AI29.375AI328.125A120V : P120 9.3751125116V : P12016 0.75101510A:P102R4 28.125228.125411753078.1251.21I10.5I2I13 V21 V2I2V23纟4271.22R2I2UsUsR4I 21UsR2 R440 200.1AIsI20.

7、1R2I 2R3R4、一0.1 0.2AI 22IsR40.3200.1A40 201.231VI31Is1 320.5 Q0.25A1 10.5 0.5 1,12 = -0.5A0.50.5120.50.75A0.251.24 KCL : 11KVL1:2I1I2 I31301202I20I115A,I210A, I325A(b)开关合在b点时，求出20V电压源单独作用时的各支路电流:KVL2:2I2 1204I30I1IiI3I3iI2Mb H + O 20V202 24202 24206A所以开关在11121 315 410 64Q4A2Ab点时，各支路电流为11A16A25 227A1

8、.25Uab (4 2) 1.5 9VUaRabIl110爲1.26戴维宁：1220 丄 110V225Q2V Uab 11 4I 10 2 4 2VRjbR241 abRabIl2252525 50U诺顿220"5025Q(2)求二端网络的等效内阻(电压源短路、电流源开路)(3)得到戴维南等效电路Rab+TzOUR1abIiUabRabR1 A 0.154A131.32(a)IiIiI2 I350 Va5010Va 50I250 VaVaVa105100v75Va20I3Va202.3.2(a)取电源为参考向量U?U2I R?I(tan60jXc)IRixC(b)Xc屈又XfcR=

9、73卫73Xc1C=71C2U2 I(jXc)tan 60Xl_,又Xl=2 fLV3旦=732 fL第二章正弦交流电课后习题2.3.2(a)取电源为参考向量60U27i60Ur?I R?U2 I(tan60jXc)IRIXcXcU2UrRfcR=73l(jXc)?I Rtan601C=2fCR73旦=爲2 fLXl,又Xl=2 fL习题2.2I15 j5, I15血AI1ii 10sin(1000t 45 )A52 45 Ai3I4i4U2,I2i2I3（1）Ui,306 30 V U28arcta n =536U =U1+U2=10 u 10屈in( t5 j5 5近 45 A10sin(

10、1000t 45 )A5 j5 52 135 A10si n(1000t 1355 j5 5210si n(1000t 135U16 30 V)V)A135 A)Ah 1030 A I2 10 60 Aarcta n1 =45?I 1/2(45 30 ) 107275 A i 20sin( t 75 )A2.4(a)以电流I为参考向量xUUlUr10 arctan =4510U 10/2714.1VU 10血 45 V(b)以电流I为参考向量RUcu2 UuR2CUc J100260280Viii25/2U sin( 逅lis in( 2 sin(t) t 90 )A t 45 )AR?为参考

11、方向以电流(c)U L?UUc(200 100) 90100 90 V100V(d)以电压 U 为参考方向I JIr2 Il2IlJ52 42 3A(e)以电压U为参考方向IJ52 52 5罷A 7.07A(f)以电压U为参考方向Ic*II Il Ic2.5IlIl Ic I(1)A/2 s in(A,18At)A314rad /sXl31.4Ic j314 100219.8309.9sin( tUL310(2)UL309.9310IlUlLXl2.6(1)sin( t127)V)V314 1003 4AUc220Xc0V Uc 220V1IcCUsXT2 3.140220 0.28A 796

12、.26796.2Ic0.28ic0.39sin( t)AUc o.12.9 (1)796.279.622072sin( t)V2200 V2 f 314rad/s10 忑s in()A1022010 022 011 11妁Xl1325060.7mHUl220 10220CV7AUlcos 220 10 cos6001100Wsin 2200 sin 6001905var2.10U1C+:U2(1)电容两端f=HZ>OL§olh()Ln(ox -x)+mhzoldnJ0+0±95 。yed u一s Hox卜。卜Lu订上2" S8 M£"n5

13、/000。7onL*/rL 一L(2)oxZInL.O I00ox一 2m (乡-2u_sox>12Soo000.H呱叵背曲灭二mJ2.13100200V100 屁si n(1000t 200)Xl3000.47si n(1000t1000 0.420°)400?IliLXc100 200400 9000.35si n(1000t 700)A1CjXL0.250AIcic2.141000 2 10 6 500100200cc宀00.20 A5009000.28si n(1000t 1100)AUjXC11400R jXL300 ( j0.003 0.0005j9。100 030

14、00以u为参考向量? iIc50)0.003900.330AXcICXlIll110AU 10RVIc10AI22.15XcXcI c1072 a10 450A(1)2.18R jXC30 j 1000 25 10 630 40 j 50530URisR300 & Si n(1000t-300)Is10300AUcIs(jXC)101200V300 40300 4 0900Uc40040072si n(1000t1200)V(2)U(3)IsZ 1030050/2 si n(1000t5053050 0830V830)VUrIsQcUIs300 10 3000WUCIS400 1040

15、00Var500 105000V? AScos(-530)=3009WSsin (-53° )=-3993Var1 UrUcUrIUlI3_108 2412 340.3HUl UcUc(12 Uc)j(12 Uc)21026V 或 18VXcUcI1.5或1"c=X c1010.067F或=0.022 F10 4.52.19 (a)(1)j3j618j3 j6j1j9j2j2j4 3j?IuZ10 002 370A5370?U123704 8370V?U2237049008530V?U3237019002530V?U423702 90°41270V?l1?U441

16、2701.33370Aj33900?u441270I20.67370A690037°UI cos 10 2 cos( 370)16W(b)(1)(j4)( j6)j3j62.4j4 3j 5 370?IU 10 002IZ 5370?370U124 90?370U224 8?370900U32?370U422.4?1270?I1U44.84j900?1270?I2U44.8j6690°乙0370V1.20.82jj2370V370A4 530V2410j2.4j90° 4.81270V370A370AUIcos102 cos(370)16W2.20ZiZ25(55

17、j5j)45010(5-5j) 10jU2100 "A10A读数为10AZ=10+10j 1o72 450U1 I1 Z迈 1ooV2/V,读数为141.4VI12.23Xc1 1C 104 1021 ( j)XlZj)104j10410622.241.50.5jUcjUc"rj212"0090.50A1 00TUr UUI cos2.290A0.50.5 j A0A(1 0.5j)2+j(1 0.5j)j2L Uc3.612j1+2jP UI cos1 2jcos(3j 3.610WP1=UT 224.501.21K1,os11 2200.51 60°

18、,PCJ 2 (ta n 1-ta n )1.21K (1.732 0.456)2I EUrS UI3.14 50 2202匹 4.54A2201022uFSsi n380 4.54 1727.3V? A177.3 (-)=-Var2.30ZrlI1R j L 12 12.56j17.37U220ZcIcZRL1j cU12.67J122 12.5621250 100 10 631.5822031.856.91AZ 总=ZRLZRLZCC Zrl 乙220=8.75AZ 总 25.15UI cos =220UI cos =22025.15cossinS=UI=220.75=1925V?Acos

19、0.96860=1864.5w0=478.73w2.31Up竽 220VV3Il 2.2A土 竺 100Ip 2.2arccos0.8 37°100 37080 60 j2.32(1)Z8 6j10UpUl38073罷I pUp22010IlIp 22A37022CV22AUl220V UP22070UL 220VIlUlIlUn2.33Up22A38A380V UPUp 38010TSI p 66A220V,UlUlU L 380V38A38CV ,Y 行22CV,形A? I RIn TNH_IBac -?*-3807 Up 220V?设U A?220U B220?U C220Ul

20、U AI A00 V00 V00 VUbRUcRI AIa2R220100 22 00 a22000700°-2200A2.34220 0010 002200A00 22Ib Ib 22222 104840W00220060.1 00A31 22 j 38380V,U p :IUzI PZ73U LIL cos7373ULILsin W S ®lIl 3817V ?A cos 0.8UlIl2.35220V竺 5.8A38COS35.603054Wsin35.60=2290VarUL 380V, Ra 11RbFC 22(1)设Ua?In220 00 V U B?瓦?Ubr

21、T? ?I A I Ba2Ra I220 0°11220 0°22?I Ba2RbI22?I ABU ABRb22000 VUc 22000 V22 00A1000A00c2Rc1022200 1011 10200 10200A8800WF2200017.300A22?I CAUCA43220002217.300A10巧 00 17.300AIc ICA 10 廳? ?IaI AB I CA?I BRc?I AB17.300 17.300A0030 00A?In?0, A0?I B?Ic?U bc7F220RbRc22?I C8.600A2.36Il5.5AP 7760Wc

22、os =22008.60OAUl=二一=1018.3VV3I L cosyj373UlIl 73 1018.3 5.5 9700V?AUlIl晅320.7 3700 320.7256.6 192.4IpIl 逅32.9 巧19AUpI PJ122UlUp380V2.38Ul380V?设uA =22000V?I A?U A22000R10?I AB?u AB220R38?I A00?I A?I A?I A 22 002.3732.9AI39.3AIl22 00A162380V1000 A00 1oV3 00A10亦 0039.3 00A第三章电路的暂态分析3.1(1)i1R1_.I R2q &g

23、t;1OOV0 Uc(0 ) U 100V0 Uc(0 ) Uc(0 ) U 100V100VUr2(° )i2(0 )100 型 1.01A99R2Uri(O )U Ur2(0 )100 100 0Vii(0 )ue0Aic(0 )ii i21.01AUR1()i1( )R11VUR2 ()i2( )R299Vic()0AUc()UR2()99V3.2(1 )换路前：t 0ij R1,1+6V"R¥L丄R4Uc+-I& R4 2KR2341KR1234R1 R234 2KiL(0)31.5uA2Kuc(0)iLR41.5uAR341K 1.5V(2)换路

24、后 t0iL(0)iL(0 )1.5mAUc(0 )Uc(0)1.5ViiRR3iL+r-*L1LH6V +r* ic+'llR4T-1.5mA61.5i1(0 )2.25mA1K1Ki2(0 )0Aic(0 )i1(0)iL(0 ) 2.25mA1.5mA 0.75mAUl(0 )1.5iLR41.5 1.5mA1K0ti1 RiR3+6V1IH1K1K】1KUciL1112ic1363KiL2V2 mA2 mAUl3.3 (1)求 Uc()t 0 Uc(0 )t 0 Uc(0 )0VUc(0 ) 0V求Uc()tUc()20V(3)求R2 6KCiC2：ZiCi C2RC 6K2j

25、 c2Cic1j c)20uF60.12sUc(t)20 (020)e证 2020e 8.33tVUc V203.4 t 0R2I3KQ6KQ尺3KQ+60VUc(0 )10m 6k 60VUc(0 ) Uc(0 )60VR210m心3KQ6KQR 3KQc 3K 6K R总=3K 6K60ic(0 )5K605K12mAR210m心3KQ丄6KQRU1R1卫3KQic( )0uc( )0R2HI3KQ6KQRo 5KRC5K2 10 610Uc(t)Uc(60uc(0 )t0尹Uc(2st)e60e 100t(V)ic(t)12mA 012e100t(mA)60i：ic mA0-123.5(

26、 1)求ic(0),Uc(v +Q50Vt 0 Uc(0 ) U -t 0 Uc(0 )Uc(0 )100R350V100ic(0)506.25A4 4(2)求ic()Uc()r-R、ZZh E1 +t,ic( ) 0A,Uc( ) U100V求R R1R2RCic(t)(6.25Uc(t)100(502 10 6st0)e2t100)e6.25e51tA100 50e5103.6Ri1U2JR2 UcR3pcJ_+Uc(0 )Ui亠10丄R R24 45Vuc(0 )Uc(0 ) 5VU2<R2U2 iR1 i2R2icR35i2R20ic(0 )0.625mAi(0 )0.3125m

27、Aicii2+o1R2Ro_R1 R2r1R2R3 2K 2K 4KUc(ic(RoC4KR2R2100 10 612i()U2R1R2Uc(t)2.52.5ic(t)0(54K 4Kt(5 2.5)e02.5e 0.5tV0.625 0)e 0.5tVe 2.5t mAi(t)0.6250.6253.70.4s2.5V0.625mA2 5t(0.3125 0.625)e2 5t0.3125e mAUc(0 )0RCUc(t)0.10.150K20 (0Uc(0.1)Uc(0.1)tUc(106t20)e 0220 20e)U 20V0.2s205 0.15t20e V(t 0.1s)7.87

28、V7.87VuR(0.1 ) Uuc(0.1 )20 7.87 12.13VtUr()0R0R25KtUr()02R)C25K4 10 60.1st 0.1UR(t)0(12.130)e o.112.13e 10t 1 V(ttUc(1t) U20VUR(t)UUc(t)12.13e 10t 1 V(t 0.1)t 0.1Uc(t)201 (7.8720)e 0.1 V3.8t0.2,RC1 1031010 6 0.01sUc(0.2)Ui(0.2)10Vt0.2，Uc(0.2 )Ui (0.2)10V0.1)Ui(0.2 ) Uc(0.2 )0 1010V0Vt 0.2(10 0)e 0.0

29、11Oe100(t0.2)V,tUi (0 ) 0VUi(0 ) 0V0.2U0(t)00 ,uc(0 )0 ,uc(0 )U0(0.2 )，Uo()U0(0 ) Ui(0 )10Vt,U0( ) 0Vu0(t) 0 (10 0)et0.0110e100V,0 t 0.2U0 Vi10 0.2-10一一3.9Uc(0 ) , Vb(0 ),Va(0 )O ,Uc(O )O ,Uc(O )g 5 1V 5 25Uc(O )1VKVL :1O)1 251(0Vb(O )Va(0求uc(1(0)0.31mA6 10 0.31Vb(O )1)，Vb( ),Va(Uc()Vb()Va()i(O ) 6

30、6 O2.9V1.9V6( 6)510 5 256 10 0.3 3VVb( ) Uc( )3 1.51.5V0.3 51.5VR 5(1O25)4.375KRC4.3751OO 1O 12t4.37510 7sUc(t)1.5(11.5)e 4.375 101.50.5eVA(t)1.5(1.9 1.5)e2.31t1.50.4eVB(t)3(2.93)e 2.31o6t3 O.1e2.310'3.1ORRshr=T 一2.3 10、2.3 106tvVub占2R2求iL(O )t 0 ,iL(0 )t0,iL(0) iti()R1iL()i2RR3R,RL10R18.75iL(t)

31、0.163.11 (1)Z乙乙0.52msUR1R3iL(0 )U40.2A5 150.2A4R,Rs5 7.50.16A15 3.75(0.2 0.16)e18.75t0.53 10 30.32A0.16 0.04e 1875tAL L1 L2 求 i1(0 )1(0 t 0 ,iL(0 )jLi0.01j L20.02j0.03HLi L2)0At 0 ,iL(0 ) iL(0L断开：ii(0 )=i2(0 求ii( ),i2(0A)=0 At ,i1()i2()RR1R22 (0 2)e2 2e 100t AURLRt0.01R20.03 cc. 0.01s3c c 100t"

32、2 2e AL1：i(t0)2Ai1(t0)i(t0 ) 2AU6i1()-3A2L,0.010.005sr2Xi1(t)3 (2t3)e 0.005c200t3 eAL2 : i2(t0 )2A i2(t0 )i2(t0 ) 2Ai2()0A0.02sL2r0.021i2(t)(2C 50t A2e A913.12求i(0),i(0 )RLRc22010A1 20 1i(0 )i(010Ai()R Rl竺 110A1 10.21 10.1s10t110 100e Ai(t) 30A,t0.02s3.13100t 0 ,i(0 )2.5A40t 0 ,i(0 )i(0 )2.5Ar rli(t

33、) 110(10t110)e 01u(0 )t ,i(L2.5R'V u(0 )V,R' 8040 R'0A,u( ) 0V1 s 40 R'求 5% 对应 t:i(t) 0 (2.5t1 0)e 际 2.5e (40 R')t400 R'R'ln0.05“ “40 60 0.0360 R'设t 0时，幵关闭合0 ,iL(0 ) 0A,t 0 时，iL(0+) 0A6时，iL()12mA25014.414 40,0.0576s2500.0288s"c 14.4250 ,5000,iL(t)2.4 (0250,iL(t)2 (0t2.4)e005762.4t12)e 002886t2.4e 0