电工电子学课后习题答案

电工电子学课后习题答案目录电工电子学课后习题答案1第一章电路的基本观点、定律与解析方法2练习与思虑2习题4第二章正弦交流电14课后习题14第三章电路的暂态解析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第九章波形的产生与变换65第十章数据收集系统67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...............................................................................................................79练习与思虑b）+36V6V-6A5Ω1A5ΩUab55215VRab5

第一章电路的基本观点、定律与解析方法a-+a42V6Ωbbaa2A5Ω+40Vb-baa+5Ω2A15V-bba6Ω+42V-bUab66642VR6ab(c)a+-

5Ω40VbUabUR10651040VR5ab(d)a3Ω+-

us6Vbus2us14KVL:21uab320uabusVRab36(2)abR2RR3R1R2R1+++++-15V6V5V5V+9V-----15Vb15Vb2R24R415Vb5Vb3R34R1KCL:1234VbVbVbVbR1R2R4R3求方程中Vb2Vb=Vb1Vb+9=Vb+9R250kR1100kKCL:Vb=Vb9Vb1V50k100kKVL:650KI+100KI9=0100KI=15I=1A10kVb=650k1=1V10k习题1.1（a）（b）

xx1

5427A0.40.70.3A(C)x4

x20.30.20.20.1A0.230x3x2x11.23

0.20.10.3A0.30.60.9A0.010.30.31A49.610.319.3A0.39.39.6A1.3P142281P211010P3428

发出功率吸取功率吸取功率P4(110)10吸取功率P发=28P发=P吸吸P=281.6R6120Ω50mv（a)uR6V(b)uR12604V601201.7a）us144V(b)Is2A5u220uVss91.8us1221014VIs21021A10P121428P2101101.9u1236.34Rx168ΩI10.45AI20.3AI30.450.30.15AI30.15106.346.3Ry0.45174.4Ω1.10(a):u2u116V(b):u251.6V16455(c):u250.16V1.6455(d):u250.160.016V4551.11u21u1R2Rp8.41VR1R2Rpu22u1R1R25.64VR2Rp1.12RCD63Ω3RBD=0.5ΩRAD1990.5199.5ΩI11015mAI25mA2I3534.2mA3.6I450.60.8mAI2I33.6uAD10199.51.995mVuBD=15=5mVPs101.9950.019951.13(a)AAAR3AR22A25A2Ω+110VBB-B(b)AA3Ω+9Ω15V-+6Ω3V--B12V+B1.153Ω+I4A6V3Ω3A3Ω-1.5Ω3Ω++I6V1.5V--1.561AI31.51.16I3-10V3Ω10Ω+10V2Ω-5Ω

3ΩI+1A1.5Ω6V-I310101A10532I1Is1I3110I0202AI2121AI416263A3I51331A631.171Ω2V1Ωa+-2A3Ω2A6ΩI2Ωb2Ω-a+I4A2Ωb2Ω2V+-+I8V2Ω-I821A2221.18I1I2I3KVL:u1I1R1I3R30I3R3I2R2u20I16I26221I37575751.19n2I118I3I2KVL:14020I16I20I36I20I14AI210AI312Au120I180Vu26I260V电压源P1404560发出功率电流源P6018108发出功率1.20n2I1I2+10IKVL:0.8I11201160.4I200.4I21164I20I18.75AI29.375AI328.125A120V:P1209.3751125116V:P120160.75101510A:P10428.1251175RL:PI2R28.125243078.1251.21I10.5I2I123V21V233I2V24V2271.22R1R3us

R2I2+usR4-I21us6R2R40.1A4020R1R2I2R3R4IsIsI20.10.10.2AI22IsR40.320R20.1AR440201.23+-

1Ω0.5ΩI31Ω1V1ΩI31110.25A0.51110.51Ω0.5ΩI31Ω1ΩIsI322110.510.5A0.52I30.250.50.75A1.24(a)KCL:I1I2I30KVL1:2I11301202I20KVL2:2I21204I30I115A,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：I1

'I3'2Ω2ΩI2'4Ωb+20V-I1'220444A242I2'2046A22I3'2022A22442因此开关在b点时，各支路电流为：I115411AI210616AI325227A1.25（b）等效变换+A-22.5A3ABUab(32.5)211V（c）等效变换aa4A4A2bbUab(42)1.59V1.26戴维宁:ua2201110V2Rab25ΩIL110122A255015诺顿：Iab22022A505Rab25ΩIL222522A52550151.28R1R22AR3R4-10V求二端网络的开路电压：ba2A

R2R3R4-U10VUab104I10242VUab104I10242V求二端网络的等效内阻（电压源短路、电流源开路）RabR24获得戴维南等效电路+RabR1UabI1Uab2RabR1A0.154A131.32（a）I1I2I3I150VAI250VAI3VA1052050VA50VAVA10520VA100V7取电源为参照向量??UIR??U2I(jXc)tan60IRRIXC3XcXCR13,又XC=2fc2fcR=3b）??U2I(jXc)??URIRtan60IR3IXCXLR,又XL=2fL3R=32fL第二章正弦交流电课后习题取电源为参照向量??UIR?I60?U2b）

??U2I(jXc)?tan60IRR3URIXCXc?XCR,又XC=13fcU122fcR=3?U260

?U1??IUR

??U2I(jXc)??URIRtan60IR3IXCXLR,又XL=2fL3R=32fL习题2.2?I15j5,I152Ai110sin(1000t45)AI15245A?I25j55245A?i210sin(1000t45)AI3?I1?5j552135AI3i310sin(1000t135)A???I45j552135AI4I2i410sin(1000t135)A2.3??UU2?U130（1）??U1630VU2630V8=53arctan6???U=U1+U2=10Vu102sin(t)V(2)?I26030??I1I??I11030AI21060Aarctan1=45?102(4530)10275AIi20sin(t75)A2.4?以电流I为参照向量?UL?U?UR10arctan=45U102V14.1V?U10245V?（b）以电流I为参照向量I?UR??UUCU2UC2UR2UC100260280Vu2Usin(t)i12I1sin(t90)Ai22I2sin(t45)A?(c)以电流I为参照方向?UL??UI?UC?U(200100)9010090VU100V?（d）以电压U为参照方向?IR?U??IILIIR2IL2IL52423A?（e）以电压U为参照方向?IC?I?UIRI525252A7.07A?（f）以电压U为参照方向?IC?U?IIIL

ICIL

IC

I

18A2.5（1）IC72sin(t)A?IL70A,2f314rad/sXLL31.4??3ULICjL70314100V219.80VuL309.9sin(t)V3102）uL309.9sin(t)V310ILUL12734AL314100XL2.6(1)?Uc2200VUc220VXC11796.2C23.1406ICUc220Xc0.28A796.2?IC0.28ic0.39sin(t)A?(2)Uc0.10796.279.6V2.9(1)u2202sin(t)V?U2200V2f314rad/si102sin(t)A?I100A2）?ZU2200?1022011113jI0LXL113260.7mH503）SUI220102200V?APUIcos22010cos6001100Wsin2200sin6001905var2.10+Ru1+u2——(1)电容两端f=HZ?以I1为参照向量=-600Rcos2k11K2Xcsin2k3)17072Xc110.1uFcXcc（2）电阻两端?I1??0URU230??U1U0=-300Rcos=2k3=170721）1000Xc=—sin=-2K（—12c0.16uFc2.12+R?LUC-RLCZ=R+(XLXC)j10UV2.13UV?200VU100iRu1002sin(1000t200)R3000.47sin(1000t200)XLL10000.4400?U100200ILjXL00.2540090iL0.35sin(1000t700)AXC11500C10002106??0U10020Ic0.2jXC500900ic0.28sin(1000t1100)A1111ZRjXLjXc1(j1j1)300400500.0030.0005j0.0039090?0?U1000AI00.33Z3002.14?以U为参照向量?IC??U?IL

A00AXCXLICIL?????I1ICILIRIRIRU10AU10RVRI3ICU10RXC10AXC???450AI2IRIC10I2102A2.15(1)ZRjXC30j11000251063040j50530uRiSR（0）V3002sin1000t-30?300AIs10??30030040900UCIs(jXC)10404001200VuC4002sin(1000t1200)V??300530830VUIsZ1050500(2)u5002sin(1000t830)V（3）PURIS300103000WQQCUCIS400104000VarSUIS500105000V?AScos（-530）=3009WSsin（-530）=-3993Var2.18?UL??UR?UCUR8R2I4UL12L3I430.3H10????UURULUC8(12UC)j2(12UC)2102UC6V或18VXCUC1.5或I1=XCC10.067F或1C10=0.022F1.5104.52.19(a)(1)Z1j3j6182jj3j69j(2)j1j2j43j5370?0?U100370AI2Z5370?370370VU1248?370900530VU2248?370900530VU3212?3709001270VU4224?0?U441271.33370AI1j33900?0?U441270I20.6737Aj66900(3)PUIcos102cos(370)16W(1)Z1(j4)(j6)242.4jj3j610jj2j2.4j43j5370(2)?0?U100370AI2?Z5370370900370VU1242?370370VU2248?370900530VU324?3709001270VU422.44.8?0?U44.8127370AI11.24j900?0?U44.8127370A0.8I2j66900(3)PUIcos102cos(370)16W2.20Z155j52450Z2(55j)j10（10j5-5j)I1U2=100=10AZ210A读数为10AZ=10+10j102450U1I1Z21002VV1读数为141.4V2.23XC111C104102106Z11(j)1j245011j1(j)j222XLL1041041Z1jZ11.50.5j2.24??0Uc100Ic0.5Aj22900??0Uc1010AIR1??IIcIR0.501010.5jA1.10A??URIR(10.5j)22+jV??ULIj2(10.5j)j22j11+2jV????0VUURULUc2j12j123j3.61PUIcos3.611.1cos(00W2.29，P1.21KPUIcos1cos1=UI112200.5P(tan1-tan）U2=1.21K(1.7320.456)1022uF23.14502202P1K4.54AI220URSUI3804.541727.3V?ASsin177.3（-）Var=-2.30ZRLRjL1212.56j17.370I1U22012.67ZRL12212.562ZC1j131.58jc250100106IcU2206.91AZc31.85Z总=ZRLCZRLZC25.150ZcZRLU=220=8.75AZ总25.15PUIcos=220cos0=1864.5wQUIcos=220sin0=478.73wS=UI=220.75=1925V?Acos0.96862.31UP3803220VIPIL2.2AUP220100IP2.2arccos0.8370Z1003708060j2.32(1)Z86j10370UPUL380220V33IPUP22022A10ILIP22A(2)UL220VUPUL220VIPUP22022A10IL3IP38A(3)UL380VUPUL380VIPUP38038A10IL3IP66A(4)UN220V,UL380V,Y行UL220V，形2.33A?INN?

RIBBXCC?ICUL380VUP220V?00设UA220V?00VUB220?00UC220V??0UA22002200AR10??0UB22000IB220AR1000??0UC22000IC220AR1000????220000220060.100AINIAIBIB22PIA2R222104840W2.34Z3122j380UL380V,UP220VILIPUP2205.8AZ38P3ULILcos3cos35.603054W3ULILsin=3sin35.60=2290VarS3ULIL3817V?Acos0.82.35UL380V,RA11，RBRC22(1)?22000V?22000V?设UAUBUC22000V?0?UA220000AIA22RA11?0?UB220000AIB10RB22????2200100010001000AINIAIBIBPIA2RAIA2RBIC2RC2221110228800W(2)??0UAB3220017.300ARB22?0?U322000AICACA017.3RC22??0000AIBIAB10317.3??00AICICA103???17.30017.3003000AIAIABICA(3)??I，0NA?0??UBC322008.600ARBRC2222?00AIC8.62.36IL5.5AP7760Wcos=UL=P=7760=1018.3V33ILcosS3ULIL31018.35.59700V?AUL1018.3320.7IL33Z320.7370256.6192.42.37IL32.9AIPIL32.919A33UPIP122162380VULUP380V2.38UL380V?0设UA=2200V??0UA22002200AIAR10?0?UAB322000IAB100AR38?000010300AIA3???22000039.300AIAIAIA103I39.3A第三章电路的暂态解析3.1(1)i1Ric+1UR2--100V+t0uc(0)U100Vt0uc(0)uc(0)U100VuR2(0)100Vi2(0)100100R2991.01AuR1(0)UuR2(0)1001000Vi1(0)uR10AR1ic(0)i1i21.01A(2)+i1R1icUR2--uc+i1()i2()U100R1R211A99uR1()i1()R11VuR2()i2()R299Vic()0Auc()uR2()99V3.2（1）换路前：t0R1R3iLi1+uc+R46V--R34R3R42KR2341KR1234R1R2342KiL(0)31.5uA2Kuc(0)iLR41.5uA1K1.5V（2）换路后t0iL(0)iL(0)1.5mAuc(0)uc(0)1.5Vi1R1R3iL+ic+1.5V6VR4--1.5mAi1(0)61.51K2.25mA1Ki2(0)0Aic(0)i1(0)iL(0)2.25mA1.5mA0.75mAuL(0)1.5iLR41.51.5mA1K0Vti1R1R3+1K1K6V1KR4-uc12V36iL2mA3Ki1

iL

2mAi2icuL

V3.3(1)求uc()t0uc(0)0Vt0uc(0)uc(0)0V(2)求uc()tuc()U20V（3）求RR26KC1C2:Z1Z21jcZZ1Z2112jcjc)CC1C22C120uFRC6K60.12s(4)tuc(t)20(020)e0.122020e8.33tVucV20ts3.4t0R23KΩR13KΩ6KΩR3+-60Vuc(0)10m6k60Vuc(0)uc(0)60Vt0R23KΩ6KΩR13KΩ10mAR3+-ucR总=3K6K5K3K6KiC(0)606012mAR总5KtR23KΩ6KΩ10mAR3iC()0uC()0R23KΩ6KΩR1R33KΩR05KRC5K2106102stu(t)u()u(0)u()e2cccct0600e10260e100t(V)tic(t)012mA0e10212e100t(mA)ucV600tsicmA0-12

ts3.5（1）求ic(0),uc()t0uc(0)UR1R3100150VR32t0uc(0)uc(0)50Vic(0U50100506.25A)R244R1(2)求ic()uc()t,ic()0A,uc()U100V求RR1R28RC82106st6.25e5105tAi(t)0(6.250)e2106ct10050e5105tVuc(t)100(50100)e21063.6t0R1R3+i2icU+1R2u-c-uc(0)u1R1104R1R25V44t0uc(0)uc(0)5VR1R3i2icU2R2+uc-ii2icU2iR1i2R2icR35i2R20ic(0)0.625mAi(0)0.3125mAt+-

R1R2R1R2R0R32K2K4KR1R2RC4K1001060.4s0uc()U2R212.5VR1R252ic()0i()U250.625mAR24K4KR1tuc(t)2.5(52.5)e0.42.52.5e0.5tVic(t)0(0.6250)e0.5tVe2.5tmAi(t)0.625(0.31250.625)e2.5t0.6250.3125e2.5tmA3.7t0uc(0)0tuc()U20VRC50K1060.2stu(t)20(020)e0.22020e5tV(t0.1s)ct0.1u(0.1)2020e50.17.87Vct0.1uc(0.1)7.87V+-+URR-uR(0.1)Uuc(0.1)207.8712.13VtuR()0R0R25KtuR()02R0C25K41060.1st0.1u(t)0(12.130)e0.112.13e10t1V(t0.1)Rtuc(t)U20VuR(t)Uuc(t)12.13e10t1V(t0.1)t0.1u(t)20(7.8720)e0.1Vc3.8t0.2,RC1103101060.01suc(0.2)ui(0.2)10Vt0.2,uc(0.2)ui(0.2)10Vu0(0.2)ui(0.2)uc(0.2)01010Vt,u0()0Vt0.210e100(t0.2)V,tu0(t)0(100)e0.010.2t0,uc(0)ui(0)0Vt0,uc(0)ui(0)0Vu0(0)ui(0)10Vt,u0()0Vtu0(t)0(100)e0.0110e100tV,0t0.2u0V100.20-10

ts3.9求uc(0)，VB(0),VA(0)t0,uc(0)0(6)51V525t0,uc(0)uc(0)1VKVL:10i(0)125i(0)660i(0)0.31mAVB(0)6100.312.9VVA(0)VB(0)11.9V求uc(),VB(),VA()uc()6(6)50.351.5V10525VB()6100.33VVA()VB()uc()31.51.5VR5(1025)4.375KRC4.37510010124.375107st0.5e2.3106tVuc(t)1.5(11.5)e4.3751071.5VA(t)1.5(1.91.5)e2.3106t1.50.4e2.3106tVVB(t)3(2.93)e2.3106t30.1e2.3106tV3.10iR1i2R3U+R2iL-求iL(0)t0,iL(0U40.2A)R3515R1t0,iL(0)iL(0)0.2Ati()U40.32AR1R2R357.5iiL()0.16A2RR3R1R2153.7518.75L100.52msR18.75tiL(t)0.16(0.20.16)e0.531030.160.04e1875tA3.11(1)ZZ1Z2LL1L2求i1(0),i2(0t0,iL(0)0,iL(0)L断开：i1(0

jL1jL2jL1L2)0.010.020.03H)0AiL(0)0A)=i2(0)=0A求i1(),i2()t,i1()U6i2()R22AR121RR1R23L0.03,30.01sRti1(t)2(02)e0.0122e100tAi1(t)22e100tA2）L1:i(t0)2Ai1(t0)i(t0)2Ai1()U6R13A2L10.01R120.005sti1(t)3(23)e0.0053e200tAL2:i2(t0)2Ai2(t0)i2(t0)2Ai2()0AL20.02R210.02sti2(t)0(20)e0.022e50tA3.12求i(0U220),i(0)Rc110ARRL201i(0)i(0)10A求i(),tU220i()RL1110AR1L0.2RRL0.1s11i(t)110(10110)ei(t)30A,t0.02s

t10t0.1110100eA3.13t0,i(0)1002.5A40t0,i(0)i(0)2.5Au(0)2.5R'Vu(0)V,R'80t,i()0A,u()0VL1s40R'40R't求对应1t:i(t)0(2.50)e400R'2.5e(40R')t5%R'ln0.0540600.0360R'设t0时，开关闭合t0,iL(0)0A,t0时，iL(0+)0At时，iL(612mA)25014.4RRL250R0,14.40.0576s250R250,14.40.0288s500ttR0,iL(t)2.4(02.4)e0.05762.42.4e0.0576ttR250,iL(t)2(012)e0.02881212e0.0288iL(t)6mA,t0.0288ln60.02ms12R:0250延时：0.01660.02ms第四章常用半导体器件4.2(1)去掉DA,DB,得UDA10V,UDB0V,DA优先导通则V1099V,D截止BF19(2)去掉DA,DB,得UDA6V,UDB5.8V,DA优先导通则VF695.4V,DB导通19VAVFVBVFVF1196VF5.8VFVF119VF5.59VIA65.590.41mAIB5.85.59110.21mAIIAIB0.62mA(3)去掉DA,DB,得UDA5V,UDB5V,DADB优先导通5VF5VFVF119VF4.73VIA54.730.27mAIB0.27mA1IIAIB0.54mA4.4R+-UZUZ+UI-IRKCLIZ4.5

+RLUZURC-URLUZRL2412VRRL28V,反向击穿RIRIRL++8VURLURL--UIUZ8RL0.08A100:IZIRIRL0.160.080.08A80mAIZmR+++UIUZURLRLRLUI---UZ=UIRRL2UZ10V反向击穿UI0VRIRIRLKCL:IRIZIRL+++UIUZIZUZRRLUI10VURLRUI10100-IZ--500500IZUI20500510330103IZ5103UI201033050022.5VUI35V4.6(1)12(2)

IIII

C112B2

20500.80.410500.80.6125.2

184.50.43847.50.8第五章基本放大电路输出端等效电路r0+RLU0U2-RL1K,U01VU0RLU'r0RL01U0'1r01RLU0'1.1Vr01005.4(1)VCC12IBRB50uA240ICIB2mAUCEVCCICRC6V（2）VCC124mAR03IC2mAUCE6VIC40IB(3)UC1UBE0UC2UCE6V5.6R??IC+Ib?RBUiRE?-+U02-（1）??U01IbRcAu1???UiIbrbe(1)IbRE10020.98(1.41012)（2）??U021IbREAu2???UiIbrbe(1)IbRE10120.9(1.41012)

+Rc?U01-Rcrbe(1)RE1RErbe(1)RE3）?0Ui1??00U01Au1Ui0.9810.98u011.39sin(t1800)mV??00U02Au2Ui0.9910.99u021.4sintmV5.7Au1200,20lg20046dB5mAU01AiRL2K100,20lg10040dBIuAm5IBIC10.05mAB20RBVCC12240KIB005mArbe200(1)26200(120)2674