東南大學(xué)電子學(xué)院《電路基礎(chǔ)》期末考試樣卷及問題詳解

Solvethefollowingproblems.<100points>1、<6points>FindUabinthecircuitinFigure1.2、<8points>FinduoandiointhecircuitinFigure2.3、<6points>InthecircuitofFigure3,readingsofvoltmeter,and錯(cuò)誤!錯(cuò)誤!錯(cuò)誤!are10V,18Vand6V,respectively.Pleasedeterminatethereadingofthevoltmeter錯(cuò)誤!.4、<8points>TheresonantortunercircuitofaradioisportrayedinFigure4,whereus1representsabroadcastsignal,giventhatR=10Ω,L=200μH,Us1rms,f1=1008kHz.Ifthecircuitisresonantwithsignalus1,pleasedeterminate:<1>thevalueofC;<2>thequalityfactorQofthecircuit;<3>thecurrentIrms;<4>thevoltageUcrms.5、<8points>Abalancedthree-phasecircuitisshowninFigure5.Calculatethephasecurrentsandvoltagesinthedelta-connectedloadZ,ifU?2200V,AZ=<24+j15>Ω,Z=<1+j1>Ω.L6、<8points>FindtheyparametersforthecircuitinFigure6.7、<15points>Forthecircuitinfigure7,findthermsvalueofthecurrentiandtheaveragepowerabsorbedbythecircuit,giventhatL10Ω,C20Ω,u(t)80100cosst50cos(2t30)V.R5Ω,R20Ω,1/128、<12points>InthecircuitofFigure8,determinatethevalueofZthatwillabsorbthemaximumpowerandcalculatethevalueofthemaximumpower.9、<14points>IftheswitchinFigure9hasbeenclosedforalongtimeandisopenedatt=0,findu,i,ufort≥0.cLk10、<15points>TheswitchinFigure10hasbeeninpositionaforalongtime.Att=0,itmovestopositionb.Findi2<t>fort≥0andsketchit.<Attention:Pleasemarkthekeydatainyourgraph.>Solvethefollowingproblems.<100points>1、<6points>FindUabinthecircuitinFigure1.Solution:Uab=9V2、<8points>FinduoandiointhecircuitinFigure2.Solution:u2.4Vo,i0.256mAo3、<6points>InthecircuitofFigure3,readingsofvoltmeter,and錯(cuò)誤!錯(cuò)誤!錯(cuò)誤!are10V,18Vand6V,respectively.Pleasedeterminatethereadingofthevoltmeter錯(cuò)誤!.Solution:Thereadingofthevoltmeter錯(cuò)誤!is10V..

4、<8points>TheresonantortunercircuitofaradioisportrayedinFigure4,whereus1representsabroadcastsignal,giventhatR=10Ω,L=200μH,Us1rms,f1=1008kHz.Ifthecircuitisresonantwithsignalus1,pleasedeterminate:<1>thevalueofC;<2>thequalityfactorQofthecircuit;<3>thecurrentIrms;<4>thevoltageUcrms.Solution:5、<8points>Abalancedthree-phasecircuitisshowninFigure5.Calculatethephasecurrentsandvoltagesinthedelta-connectedloadZ,ifU?2200V,AZ=<24+j15>Ω,ZL=<1+j1>Ω.Solution:?11.74-3.69A,U?33228.31VA'B'IA'B'6、<8points>FindtheyparametersforthecircuitinFigure6.Solution:7、<15points>Forthecircuitinfigure7,findthermsvalueofthecurrentiandt50cos(2theaveragepowerabsorbedbythecircuit,giventhatL10Ω,R5Ω,R20Ω,1/C20Ω,u(t)80100cosst30)V.12Solution:P=P0+P1+P28、<12points>InthecircuitofFigure8,determinatethevalueofZthatwillabsorbthemaximumpowerandcalculatethevalueofthemaximumpower.Solution:5jIfΩ,Zwillabsorbthemaximumaveragepower.ZZeq131UP4R119.62249.7WThemaximumaveragepoweris,OC4513maxeq9、<14points>IftheswitchinFigure9hasbeenclosedforalongtimeandisopenedatt=0,finduc,iL,ukfort≥0.Solution:i1.5(01.5)e40t1.51.5e40tA,t0,L10、<15points>TheswitchinFigure10hasbeeninpo