MOOC Electrotechnics Ⅰ (Electrical Technology)-Dalian University of Technology 中國大學慕課答案

MOOCElectrotechnicsⅠ(ElectricalTechnology)-DalianUniversityofTechnology中國大學慕課答案Quiz1、問題：Adevicethatsupplieselectricalenergyorsignals.Itiscalled().選項：A、sourceB、loadC、IntermediatelinkD、circuit正確答案:【source】2、問題：Whichoneofthefollowingisnotasignalcircuit().選項：A、amplifiercircuitB、filtercircuitC、SignalgeneratingcircuitD、powerdistributing正確答案:【powerdistributing】3、問題：Thecircuitinthefigureisasimpletemperaturemeasuringcircuit.Itisa()circuit.選項：A、powercircuitB、signalcircuitC、motorcircuitD、noneoftheabove正確答案:【signalcircuit】4、問題：Whichofthefollowingisanactivetwo-terminalnetwork?().選項：A、B、C、D、正確答案:【】5、問題：Whatdoesitusuallymeanwhenwesaytheloadincreases?選項：A、powerB、voltageC、currentD、resistance正確答案:【power#current】6、問題：WhichofthefollowingisnotAC?選項：A、B、C、D、正確答案:【#】Quiz1、問題：Whatisthepotentialofpointb?().選項：A、8VB、6VC、2VD、4V正確答案:【2V】2、問題：Whatisthepotentialofpointb?().選項：A、2VB、6VC、-6VD、-2V正確答案:【-6V】3、問題：Workdonebynon-electricfieldtomoveaunitchargethroughthesource.()選項：A、EMFB、voltageC、potentialD、power正確答案:【EMF】4、問題：Whatisthepowerconsumedbythebulbwithacurrentof1.6Awhenavoltageof6Visconnectedacrossit?().選項：A、926WB、7.6VC、976WD、9.6W正確答案:【9.6W】Quiz1、問題：GiventhatUS=100V，terminalvoltageR0=10ohm,currentI=4A，FindthepowerprovidedbythesourceP(Poweroutput)?選項：A、60WB、240WC、400WD、40W正確答案:【240W】Quiz1、問題：Findthepotentialofpointa.選項：A、-2VB、0VC、2VD、4V正確答案:【2V】Quiz1、問題：Findoutwhichonewillabsorbpower?選項：A、OnlythecurrentsourceB、OnlythevoltagesourceC、BothcurrentsourceandvoltagesourceD、Neitherofthem正確答案:【Onlythevoltagesource】Quiz1、問題：thevoltagesourceandthecurrentsourcecanbeconvertedtoeachother.ThenfindIs.().選項：A、3AB、30AC、10AD、300A正確答案:【3A】Quiz1、問題：FindtheterminalvoltageU().選項：A、U=Us+IRB、U=-Us-IRC、U=Us-IRD、U=-Us+IR正確答案:【U=Us-IR】2、問題：FindtheterminalvoltageU().選項：A、U=-Us+IRB、U=-Us-IRC、U=Us-IRD、U=Us+IR正確答案:【U=-Us+IR】3、問題：Thenumberofbranchesis().選項：A、3B、4C、5D、6正確答案:【4】4、問題：Thenumberofbranchesis().選項：A、4B、5C、6D、7正確答案:【6】Quiz1、填空題：Acircuithas3nodesand7branches.Thenumberofcurrentequationsandvoltageequationsshouldbelistedrespectivelywhenusingbranchcurrentmethodtosolvethecurrentofeachbranch.Thenumberofthevoltageequationsis().正確答案:【5】2、填空題：FindI=()A.正確答案:【5】Quiz1、問題：FindIbysuperpositiontheorem.選項：A、1AB、2AC、5AD、4A正確答案:【4A】Quiz1、問題：FindIbyThévenin'sTheorem().選項：A、1AB、2AC、3AD、4A正確答案:【1A】AssignmentsforChapterOneAssignmentsforChapterOne-2TestforChapterOne1、問題：InthecircuitshowninthefollowingFigure.WhentheresistanceR2increases,thecurrentIwill().選項：A、increaseB、decreaseC、remainthesameD、notsure正確答案:【increase】2、問題：InthecircuitshowninthefollowingFigure,thevoltagebetweentheAandB,ＵABis（）.選項：A、-2VB、2VC、-1VD、3V正確答案:【-2V】3、問題：InthecircuitshowninthefollowingFigure.WhentheresistanceR1increases,thevoltageＵ2will（）.選項：A、increaseB、decreaseC、remainthesameD、notsure正確答案:【remainthesame】4、問題：FindthevoltageＵ=()V.選項：A、10VB、20VC、15VD、-15V正確答案:【15V】5、問題：Findthecircuitelementsthatprovidepower().選項：A、voltagesourceandcurrentsourceB、currentsourceC、votagesourceD、notsure正確答案:【currentsource】6、問題：InthecircuitshowninthefollowingFigure.I=().選項：A、6AB、4AC、2AD、-2A正確答案:【2A】7、問題：GiventhatU=2V,findthepowergeneratedbythevoltagesourcePs=().選項：A、2.4WB、9.6WC、4.8WD、4W正確答案:【2.4W】8、問題：InthecircuitshowninthefollowingFigure.UAB=().選項：A、-1VB、1VC、-2VD、2V正確答案:【1V】9、問題：InthecircuitshowninthefollowingFigure.I=().選項：A、0.5AB、-1AC、1.5AD、2A正確答案:【2A】10、問題：Findtherightexpression.()選項：A、B、C、D、Noneoftheabove正確答案:【】11、問題：FindU=().選項：A、22VB、2VC、-2VD、-22V正確答案:【-2V】12、問題：GiventhatU=0.FindUS=().選項：A、-40VB、-60VC、60VD、40V正確答案:【40V】13、問題：Whatisthemeaningoftheloadin“LoadDecrease”?選項：A、resistanceB、voltageC、powerD、potential正確答案:【power】14、問題：FindthepotentialofA.選項：A、12VB、10VC、8VD、6V正確答案:【8V】15、問題：FindtheterminalvoltageU=().選項：A、-2VB、2VC、18VD、-18V正確答案:【-18V】16、填空題：FindI=()A正確答案:【1】17、填空題：FindUoc=()V.正確答案:【-8】18、填空題：FindI=()A.正確答案:【4.8】19、填空題：FindI=()A.正確答案:【3】20、填空題：FindUoc=()V.正確答案:【2】21、填空題：FindI=()A.正確答案:【2】22、填空題：FindtheequivalentresistanceRab=()ohm.正確答案:【4】23、填空題：FindI=()A.正確答案:【2】24、填空題：FindI=()A.正確答案:【1】25、填空題：FindＵab=()V,whentheswitchisopen.正確答案:【5】Quiz1、問題：Ifthevoltageacrosstheinductoriszero,thestoredenergyiszero.選項：A、正確B、錯誤正確答案:【錯誤】2、問題：Iftheswitchisclosedatt=0,therewillbeatransientprocess.選項：A、正確B、錯誤正確答案:【錯誤】Quiz1、問題：Thecircuitisstable.Theswitchisclosedatt=0.Theni(0+)is().選項：A、2AB、5AC、0AD、4A正確答案:【2A】Quiz1、問題：Thefollowingcircuitisafirstordercircuit.選項：A、正確B、錯誤正確答案:【錯誤】2、問題：Thefollowingcircuitisafirstordercircuit.選項：A、正確B、錯誤正確答案:【正確】Quiz1、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Theni(0+)=().選項：A、0.6AB、1.2AC、0.3AD、0A正確答案:【0A】2、問題：Thecircuitisstablebeforeswitching(noenerystorage).Theswitchisclosedatt=0.Theni(0+)is().選項：A、1.2AB、0.6AC、0AD、1A正確答案:【0A】Quiz1、問題：Thecircuitisstable.Theswitchisclosedatt=0.Thenthetimeconstantis().選項：A、0.4sB、0.8sC、0.2sD、0.1s正確答案:【0.2s】2、問題：Theswitchisclosedatt=0.Thenthesteadystatevalueuis().選項：A、3VB、9VC、6VD、0V正確答案:【3V】Quiz1、問題：Theswitchisthrownfromatobatt=0,thenthetypeofresponseis().選項：A、Zero-stateresponseB、Zero-inputresponseC、CompleteresponseD、Noneoftheabove正確答案:【Completeresponse】2、問題：TheswitchisthrownfromAtoBatt=0,thenthetypeofresponseis().選項：A、Zero-stateresponseB、Zero-inputresponseC、CompleteresponseD、Noneoftheabove正確答案:【Zero-inputresponse】AssignmentsforChapterTwoTestforChapterTwo1、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstant=().選項：A、3.6sB、1.8sC、1.2sD、0.9s正確答案:【1.8s】2、問題：Thecircuitisstable.ThenI=().選項：A、2AB、4AC、6AD、0A正確答案:【2A】3、問題：Thecircuitisstable.ThenI=().選項：A、0AB、2AC、3AD、1A正確答案:【2A】4、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstantis().選項：A、1.5sB、2sC、0.5sD、1s正確答案:【1s】5、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstantis().選項：A、0.01sB、0.02sC、0.1sD、0.2s正確答案:【0.2s】6、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstantis().選項：A、3sB、2sC、6sD、9s正確答案:【2s】7、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thentheinitialvalueofthevoltageacrosstheresistorof3is().選項：A、9VB、0VC、6VD、3V正確答案:【9V】8、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.ThenthesteadystateofuCis().選項：A、10VB、15VC、30VD、3V正確答案:【15V】9、問題：Thecircuitisstablebeforeswitching.Theswitchisopenatt=0.Theni(0+)is().選項：A、1.2AB、0.6AC、0AD、1.5A正確答案:【1.2A】10、問題：Thecircuitisstablebeforeswitching.Theswitchisopenatt=0.Thenthetimeconstantis().選項：A、22.5sB、24sC、1sD、1.5s正確答案:【1.5s】11、問題：Thecircuitisstablebeforeswitching.Theswitchisthrowntopoatt=0.Thenthetimeconstantis().選項：A、0.2sB、24sC、1sD、1.5s正確答案:【0.2s】12、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.ThenuL(0+)=().選項：A、12VB、-12VC、0VD、6V正確答案:【-12V】13、問題：Thecircuitisstablebeforeswitching.Theswitchisthrownfrom1to2att=0.TheniC(0+)=().選項：A、6AB、-3AC、0AD、3A正確答案:【3A】14、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.TheniC(0+)=().選項：A、15mAB、30mAC、0mAD、-15mA正確答案:【15mA】15、問題：Thecircuitisstablebeforeswitching.Theswitchisthrownfrom1to2att=0.ThenthesteadystatevalueofuC=().選項：A、6VB、-3VC、0VD、3V正確答案:【0V】16、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0,thenthetimeconstantis().選項：A、0.3sB、0.15sC、0.1sD、1s正確答案:【0.1s】17、問題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0,thenthetimeconstantis().選項：A、0.1sB、0.15sC、0.2sD、1s正確答案:【0.1s】18、填空題：GiventhatuC(0-)=30V.Theswitchisclosedatt=0.ThenuL(0+)=()V.正確答案:【10】19、填空題：Thecircuitisstablebeforeswitching.Theswitchisopenatt=0,thenthetimeconstantis()s.正確答案:【1】20、填空題：Thecircuitisstablebeforeswitching.Theswitchisopenatt=0.Findu(0+)=()V.正確答案:【8】21、填空題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Findi2(0+)=()A.正確答案:【1】22、填空題：Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.ThenuL(0+)=()V.正確答案:【8】Quiz1、問題：Giventhati=10sin（1000t–70°）A.Findtheinitialphase().選項：A、70°B、110°C、–70°D、20°正確答案:【–70°】2、問題：Giventhati=10sin（1000t–70°）A.Theeffectivevalueofthecurrentis()A.選項：A、10B、14.14C、–10D、7.07正確答案:【7.07】3、問題：Theunitofangularfrequencyis().選項：A、rad/sB、HzC、sD、rad正確答案:【rad/s】Quiz1、問題：選項：A、B、C、D、正確答案:【Quiz】1、問題：選項：A、7B、3C、4D、5正確答案:【5】Quiz1、問題：Giventhatu=14.14sin314tV,C=140μF,thentheeffectivevalueofthecurrentiisabout()A.選項：A、0.44B、0.07C、0.63D、0.1正確答案:【0.44】Quiz1、問題：選項：A、50B、25C、43.3D、noneoftheabove正確答案:【25】2、填空題：Thereadingofthevoltmeteris()V.正確答案:【5】3、填空題：Thereadingofthevoltmeteris()V.正確答案:【10】Quiz1、填空題：FindtheeffectivevalueofthecurrentI=()A.正確答案:【(21,23)】Quiz1、填空題：Thereadingoftheammeteris()A.正確答案:【5】2、填空題：Thereadingoftheammeteris()A.正確答案:【4】3、填空題：Findthetotalimpedance().正確答案:【10】Quiz1、問題：InaseriesRLCACcircuit,ifthecurrentinthecircuitisI,thetotalvoltageisU,theactivepowerisP,thereactivepowerisQ,andtheapparentpowerS,thentheimpedanceis().選項：A、B、C、D、正確答案:【】2、問題：InaseriesRLCACcircuit,theactive(average)powerP=().選項：A、B、C、D、正確答案:【】Quiz1、問題：選項：A、B、C、D、正確答案:【】2、問題：Inordertoimprovethepowerfactorofinductiveloadcircuit,thecommonlyusedmethodis（).選項：A、SeriesinductanceB、SeriescapacitanceC、ParallelinductanceD、Parallelcapacitance正確答案:【Parallelcapacitance】AssignmentsforChapterThreeAssignmentsforChapterThree-2TestforChapterThree1、問題：Findtheinitialphaseofu().選項：A、90°B、180°C、30°D、–90°正確答案:【–90°】2、問題：Giventhati=100sin（314t－30°）A,u=311sin（314t+60°）VFindthephasedifferencebetweenuandi().選項：A、–90°B、30°C、–30°D、90°正確答案:【90°】3、問題：SeriesRLCACcircuit.GiventhatXL=XC=20Ω，R=10Ω，theeffectivevalueoftotalvoltageis220V.Thentheeffectivevalueofthevoltageacrossthecapacitoris().選項：A、0VB、440VC、220VD、200V正確答案:【440V】4、問題：Twosinusoidalalternatingcurrentsi1andi2.I1=I2=4A.Thetotalcurrenti=i1+i2.Theeffectivevalueofthetotalcurrentisstill4A,thenthephasedifferencebetweenthemis().選項：A、180°B、120°C、90°D、60°正確答案:【120°】5、問題：WhensinusoidalACcurrentpassesthrougharesistiveelement,whichofthefollowingrelationiscorrect().選項：A、B、C、D、正確答案:【】6、問題：Inapureinductivecircuit,iftheinitialphaseofcurrentis-60°,thentheinitialphaseofvoltageis().選項：A、30°B、60°C、90°D、120°正確答案:【30°】7、問題：Inacapacitivecircuit.XC=100Ω.Thevoltageacrossthecapacitoris,thenitscurrentshouldbe().選項：A、B、C、D、正確答案:【】8、問題：hesamecoil(canbeseenasaresistorconnectedinserieswithandinductor)isconnectedtoDCandACpowersupplyrespectively.ThentheinductivereactanceXLis()Ω.選項：A、20B、16C、8D、32正確答案:【16】9、問題：Whichoneisright?()選項：A、uileadsuoB、uianduoareinphaseC、uilagsuoD、uianduoareoutofphaseby180正確答案:【uilagsuo】10、問題：Thereadingofthevoltmeteris()V.選項：A、4B、32C、12D、28正確答案:【32】11、問題：ThephasordiagramofterminalvoltageandcurrentisshownintheFigure.Thecircuitexhibit()characteristics.選項：A、resistiveB、capacitiveC、inductiveD、noneoftheabove正確答案:【capacitive】12、問題：SeriesRLCACcircuit，Findtherightexpressionof（）.選項：A、B、C、D、noneoftheabove正確答案:【】13、問題：InanACcircuit,thevoltageappliedacrossthecircuitis選項：A、0B、100C、200D、正確答案:【0】14、問題：Thepowersourcesinthethreecircuitsarethesame,thebulbsarethesameandcanemitlight,whichbulbisthebrightest?()選項：A、B、C、D、正確答案:【】15、問題：Acoilandacapacitorareconnectedinseries.GiventhatR=4Ω，XL=3Ω，u=220sin(314t+π/4)V，i=44sin(314t+84°)A.ThenXC=()Ω選項：A、3B、4C、5D、6正確答案:【6】16、問題：GiventhatR=60Ω,C=125μF,.Thentheeffectivevalueofiis().選項：A、0B、2.2C、1D、1.1正確答案:【1.1】17、問題：TheACpowersupplyvoltageremainsunchanged.Whenthefrequencydecreases,thevoltmeterreadingwill().選項：A、increaseB、decreaseC、remainunchangedD、noneoftheabove正確答案:【decrease】18、問題：Findthetotalimpedance().選項：A、B、C、D、正確答案:【】19、問題：Anincandescentlampisconnectedinserieswithacapacitor.TheACpowersupplyvoltageremainsunchanged.Whenthefrequencydecreases,thecapacitivereactanceXCwill().選項：A、increaseB、decreaseC、remainunchangedD、noneoftheabove正確答案:【increase】20、問題：Ginventhat選項：A、B、C、D、正確答案:【】21、問題：Whichofthefollowingisnotright?()選項：A、B、C、D、正確答案:【】22、填空題：Thereadingofthevoltmeteris()V.正確答案:【5】23、填空題：SeriesRLCcircuit,Givethat:URL=100V,UC=60V,Thetotalvoltageandthetotalcurrentisinphase.Thenthetotalvoltageis()V.正確答案:【80】24、填空題：正確答案:【10】25、填空題：GiventhatR=20Ω,L=48mH,正確答案:【(8,9)】Quiz1、問題：Thethree-phase?-connectedgeneratorisdrivingabalancedloadsuchthateachphasecurrentis10Ainmagnitude.When=10∠30°A,then=().選項：A、10∠150°AB、17.3∠150°AC、17.3∠120°AD、10∠120°A正確答案:【17.3∠120°A】2、問題：Inacertainthree-wire,Y-connectedgenerator,thephasevoltagesare1.0kV.themagnitudeofthelinevoltagesis（）kV.選項：A、1.0B、1.414C、1.732D、2.0正確答案:【1.732】3、問題：Inathree-phasesystem,thevoltagesareseparatedby().選項：A、90B、30C、180D、120正確答案:【120】Quiz1、問題：Ifthesourcelinevoltagesare380V,Y-connectedload,themagnitudeoftheloadlinevoltagesis().選項：A、380VB、220VC、660VD、537V正確答案:【380V】2、問題：AcertainY-connectedsourceproducesphasecurrentsof15A.iftheloadisY-connected,eachloadphasecurrentis().選項：A、26.0AB、8.66AC、5.0AD、15.0A正確答案:【15.0A】3、問題：AY-connectedsourcedrivinga?-connectedload.Thelinevoltagesofsourceare380V,eachimpedanceofabalancedthree-phaseloadis85.6+j50.Theloadlinecurrentsare()A..選項：A、3.8B、6.6C、2.2D、1.0正確答案:【6.6】Quiz1、問題：=30V,=1.2A,andthepowerfactoris0.257.ThetotalapparentpowerinabalancedY-connectedloadis().選項：A、62.35VAB、47.52VAC、108VAD、36VA正確答案:【62.35VA】2、問題：Theaveragepowerineachphaseofabalancedthree-phasesystemis1,200W,andthetotalpoweris().選項：A、1200WB、3600WC、400WD、7200W正確答案:【3600W】3、問題：InacertainY-connectedbalancedload,thelinevoltagesare380Vandtheimpedancesare30+j40?.thetotalreactivepoweris().選項：A、4.011kvarB、5.670kvarC、2.316kvarD、1.337kvar正確答案:【2.316kvar】AssignmentsforChapterFourTeatforChapterFour1、問題：Twomajorpartsofanacgeneratorare().選項：A、rotorandstatorB、rotorandstabilizerC、regulatorandslip-ringD、magnetsandbrushes正確答案:【rotorandstator】2、問題：Thephasecurrentproducedbyacertain240V,Y-connectedgeneratoris12A.Thecorrespondinglinecurrentis().選項：A、36AB、4.0AC、12AD、6.0正確答案:【12A】3、問題：Acertain?-connectedgeneratorproducesphasevoltagesof30V.Themagnitudeofthelinevoltagesare().選項：A、10VB、30VC、90VD、noneofthese正確答案:【30V】4、問題：Ifthesourcephasevoltagesofa?-Ysystem（A?-connectedsourcedrivingaY-connectedload）are220V,themagnitudeoftheloadphasevoltagesis（）.選項：A、220VB、380VC、127VD、73,3正確答案:【127V】5、問題：Abalanced,three-phase,-connectedloadhasalinevoltageof200Vandatotalpowerconsumptionof4800Watalaggingpowerfactorof0.8.Thephasecurrentofeachloadis().選項：A、10AB、17.31AC、14.14AD、Noneofthese正確答案:【10A】6、問題：Voltagesacrossthegeneratorwindingsarecalledlinevoltages選項：A、正確B、錯誤正確答案:【錯誤】7、問題：AY-connectedsystemcanhaveeitherthreeorfourwires.選項：A、正確B、錯誤正確答案:【正確】8、問題：Ina?-connectedgeneratorthelinecurrentsandthephasecurrentsareequal.選項：A、正確B、錯誤正確答案:【錯誤】9、問題：Inabalancedsystemtheneutrallinecanberemoved.選項：A、正確B、錯誤正確答案:【正確】10、問題：Inacertain?-connectedbalancedload,thelinevoltagesare250Vandtheimpedancesare50∠30°?.thetotalapparentpoweris3.75kVA.選項：A、正確B、錯誤正確答案:【正確】Quiz1、問題：TheunitofMagneticfluxis().選項：A、A/mB、H/mC、TeslaD、Wb正確答案:【Wb】2、問題：MagneticFluxperunitofcross-sectionalareais().選項：A、MagneticFluxDensityB、MagneticFieldIntensityC、MagneticPermeabilityD、MagnetomotiveForce正確答案:【MagneticFluxDensity】3、問題：MagneticFluxDensityBisavector.WhileMagneticFieldIntensityHisnotavector.選項：A、正確B、錯誤正確答案:【錯誤】4、問題：MagneticFluxDensityBdependsonboththecurrentandmaterialproperties.選項：A、正確B、錯誤正確答案:【正確】Quiz1、問題：Whatisthemeaningof?選項：A、MainfluxB、LeakagefluxC、ExcitationcurrentD、Ironcore正確答案:【Leakageflux】2、問題：Whatisthemeaningof?選項：A、CoerciveforceB、PermeabilityC、MainfluxD、Remanence正確答案:【Remanence】3、問題：Whichoneissoftmaterialaccordingtothehysteresisloopsoffourdifferentmagneticmaterials?選項：A、B、C、D、正確答案:【】4、問題：Aclosedpathfollowedbymainmagneticfluxisknownasa().選項：A、MagneticcircuitB、ElectriccircuitC、MagneticsaturationcircuitD、Noneoftheabove正確答案:【Magneticcircuit】5、問題：ThechangeofBalwayslagsbehindthechangeofH.Thisphenomenoniscalled().選項：A、MagneticsaturationB、HighpermeabilityC、HysteresisD、initialmagnetizationcurve正確答案:【Hysteresis】Quiz1、問題：Whatisthemeaningof?選項：A、PermeabilityoftheairgapB、ReluctanceoftheairgapC、LengthoftheairgapD、Lengthofthemagneticcircuit正確答案:【Permeabilityoftheairgap】2、問題：TheequivalentofthecurrentIinmagneticohm'slawis()?選項：A、FluxB、ReluctanceC、MMFD、Resistance正確答案:【Flux】3、問題：WhatisMMF?選項：A、MagneticMachineForceB、MagnetomotiveForceC、MagneticMotionForceD、MagnetomotionForce正確答案:【MagnetomotiveForce】4、問題：WhathappenstotheMMFwhenthemagneticfluxdecreases?選項：A、IncreasesB、DecreasesC、RemainsconstantD、Noneoftheabove正確答案:【Decreases】Quiz1、問題：WhichoneisnotthemajorpartofElectromagnet?選項：A、IroncoreB、rotorC、MovingironD、Excitationwinding正確答案:【rotor】Quiz1、問題：GiventhatthemagneticcircuitofDCelectromagnet.ThevoltageUisconstant.HowwillthecoilcurrentIchangewhentheairgaplengthincreases().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【remainunchanged】2、問題：GiventhatthemagneticcircuitofDCelectromagnet.ThevoltageUisconstant.HowwilltheMagneticfluxchangewhentheairgaplengthincreases().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【decrease】Quiz1、問題：GiventhatthemagneticcircuitofACelectromagnet.ThevoltageUisconstant.HowwillthecoilcurrentIchangewhentheairgaplengthincreases().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【increase】2、問題：GiventhatthemagneticcircuitofACelectromagnet.ThevoltageUisconstant.HowwilltheMagneticfluxchangewhentheairgaplengthincreases().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【remainunchanged】Quiz1、問題：Whichofthefollowingplaysaroleintransmittingelectricenergyinthetransformer（）.選項：A、currentB、voltageC、leakagefluxD、Mainmagneticflux正確答案:【Mainmagneticflux】2、問題：Theworkingprincipleoftransformerisbasedon（）.選項：A、Ohm'slawB、kirchoff`slawC、Faraday’slawofelectromagneticinductionD、Thermaleffectofcurrent正確答案:【Faraday’slawofelectromagneticinduction】Quiz1、問題：Theexternalcharacteristicofpowertransformerisrelatedtothenatureofload.Whentheloadisinductive,itsexternalcharacteristiccurvewillbe（）.選項：A、B、C、D、正確答案:【】2、問題：Theratedcapacityofasingle-phasetransformerisSN=50kV·A,theno-loadcurrentI0is3%oftheratedcurrent,theratedvoltagesare10kV/230V,thesecondarysidevoltageatfullloadis220V,FindthevoltageregulationVR.（）.選項：A、4.35%B、3%C、5%D、0正確答案:【4.35%】Quiz1、問題：Whenthereisaload,themainmagneticfluxofthetransformerisgeneratedby().選項：A、PrimarycurrentI1B、SecondarycurrentI2C、PrimarycurrentI1andSecondarycurrentI2togetherD、NeitherprimarycurrentI1norsecondarycurrentI2正確答案:【PrimarycurrentI1andSecondarycurrentI2together】2、問題：Atransformerisoperatingatnoloadconditionwithratedvoltageof220Vappliedtotheprimaryside,andtheresistanceoftheprimarywindingismeasuredas10.Trytofindtheprimarycurrent().選項：A、22AB、10AC、Approximateto0AD、Noneoftheabove正確答案:【Approximateto0A】Quiz1、問題：AloadwithRL=8isconnectedtoasignalsourcethroughatransformer,theinternalresistanceR0ofthesignalsourceis800,andthenumberofturnsN1oftheprimarywindingofthetransformeris1000.iftheloadgetsthemaximumpowerthroughimpedancematching,thenumberofturnsN2ofthesecondarywindingofthetransformershouldbe().選項：A、100B、1000C、500D、Noneoftheabove正確答案:【100】Quiz1、問題：A10kV·Atransformersuppliespowertoaloadwithapowerfactorof0.8infullload.Giventhatthecorelossis300W,thecopperlossis400W.Ignorethevoltageregulation.Findtheefficiencyofthetransformer().選項：A、30%B、80%C、92%D、100%正確答案:【92%】Quiz1、問題：Thesiliconsteelsheetusedintransformercoreismaterial().選項：A、B、C、D、正確答案:【】AssignmentsforChapterFiveTestforChapterFive1、問題：TwoidenticalACironcore-windingsarepoweredbytwovoltagesources.Thevoltagesofthetwopowersourcesarethesamewhilethefrequenciesaredifferent(f1f2),thenwhichfollowingdescriptionisrightabout1()2.C、=D、notsure正確答案:【】2、問題：ForDCcorecoil,whenthenumberofturnsNofthecoilisdoubled,thenthemagneticfluxwill（）.選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【increase】3、問題：ForanACcorecoil,whenthecorecross-sectionalareaAisdoubled,themagneticfluxwill().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【remainunchanged】4、問題：ADCelectromagnetwithratedvoltageof100VisconnectedtoanACpowersupplywithvoltageof100V.CoilcurrentIwill().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【decrease】5、問題：ADCelectromagnetwithratedvoltageof100VisconnectedtoanACpowersupplywithvoltageof100V.Magneticfluxthroughthecoilwill().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【decrease】6、問題：Therelationshipbetweencopperlossofatransformeris().選項：A、proportionaltoloadcurrentsquaredB、proportionaltoloadcurrentC、inverselyproportionaltocurrentD、independentofload正確答案:【proportionaltoloadcurrentsquared】7、問題：Therelationshipbetweenironlossofatransformerandtheload().選項：A、increaseswiththeincreaseoftheloadB、decreaseswiththeincreaseoftheloadC、IthasnothingtodowiththeloadandremainsunchangedD、notsure正確答案:【Ithasnothingtodowiththeloadandremainsunchanged】8、問題：AloadRL=8isconnectedtoasignalsourcethroughatransformer.TheinternalresistanceR0ofthesignalsourceis800,andthenumberofturnsoftheprimarywindingN1is1000.Iftheloadgetsthemaximumpowerthroughimpedancematching,thenthenumberofturnsofthesecondarywindingN2shouldbe().選項：A、800B、100C、1000D、500正確答案:【100】9、問題：Asingle-phasetransformerwithratedcapacityofSN=50kV?Aandtheratedvoltageof10kV/230V.Giventhattheno-loadcurrentI0is3%ofratedcurrentandtheoutputvoltageatfullloadis220V.Thenthevoltageregulationis().選項：A、0B、3%C、4.35%D、100%正確答案:【4.35%】10、問題：Forcapacitiveload,whenthecurrentonthesecondarysideincreases,theoutputvoltageonthesecondarysidewill().選項：A、increaseB、decreaseC、remainunchangedD、notsure正確答案:【increase】11、填空題：ACelectromagnet,IfUandfremainthesame.Thecurrentiwill(increase/reduce/unchanged)whentheairgapisdecreased.正確答案:【reduce】12、填空題：Atransformerisusedforimpedancematching.Theresistanceofthespeakershouldbeincreasedfrom4Ωto100Ωinordertoconnectproperlywiththeamplifier.Howmuchistheimpedancetransformationratio.正確答案:【5】13、填空題：TwoidenticalACironcore-windingsarepoweredbytwovoltagesources.Thevoltagesofthetwopowersourcesarethesamewhilethenumberofturnsaredifferent(N1N2),then12.(,,=)正確答案:【<】14、填空題：A50kV·Asingle-phasetransformerwhichratedvoltageis6600/230V.cosφ2=0.8.Giventhatthecorelossis600W,thecopperlossis1500W.U2=220V(full-loading).Findtheefficiencyofthetransformer(full-loading).%正確答案:【(94,95)】15、填空題：Asingle-phasetransformerwithacapacityof50kV×Aandratedvoltageof3300/220V.Thetransformerisoperatingatitsratedcapacity.Iffluorescentlamps(40W,220V)withpowerfactorof0.5areusedonthesecondaryside,howmanylampscanbeconnectedalltogether(ignorethelossofballast).正確答案:【625】Quiz1、問題：WhichoneisnotthemajortypeOfasynchronousmotorbasedontypeoftherotorwinding?()選項：A、Squirrel-cagesynchronousmotorB、SlipringsynchronousmotorC、PowersynchronousrotorD、Notsure正確答案:【Powersynchronousrotor】2、問題：What’sthenameofthemotorcomponentinthepicture().選項：A、StatorB、RotorC、fanD、Wiringbox正確答案:【Rotor】3、問題：Whichoneofthefollowingisnotawoundrotor?()選項：A、B、C、D、正確答案:【】4、問題：Asynchronousmotorisalsocalled()?選項：A、InductionmotorB、DCmotorC、StepmotorD、Notsure正確答案:【Inductionmotor】Quiz1、問題：Findthesynchronousspeedofthemotorwhosestatorcoreisshowninthepicture.()選項：A、1500r/minB、1000r/minC、750r/minD、600r/min正確答案:【750r/min】2、問題：Whatarethesynchronousspeedswhenthepairsofpolesis3atafrequencyof60Hz?()選項：A、1500r/minB、1200r/minC、1000r/minD、500r/min正確答案:【1200r/min】Quiz1、問題：Themaximumtorqueofthree-phaseasynchronousmotoris().選項：A、proportionaltothevoltageB、proportionaltothevoltagesquaredC、inverselyproportionaltothevoltageD、inverselyproportionaltothevoltagesquared正確答案:【proportionaltothevoltagesquared】2、問題：Athree-phaseasynchronousmotorwithratedspeedof1450r/min.Findthepairsofpoles().選項：A、2B、4C、6D、8正確答案:【2】3、問題：Whatisthevalueofslipatthemomentofstarting?()選項：A、1B、0C、2D、0.2正確答案:【1】Quiz1、問題：Theoutputpowerofathree-phaseasynchronousis().選項：A、HeatB、ElectricpowerC、MechanicalpowerD、Noneoftheabove正確答案:【Mechanicalpower】2、問題：Findtheunitoftorque().選項：A、WB、rad/sC、r/minD、N·m正確答案:【N·m】Quiz1、問題：Thepowerinput(electricpower)ofthemotoris()kW.選項：A、2.2B、3.58C、4.21D、noneoftheabove正確答案:【3.58】2、問題：Theratedpowerofthree-phaseasynchronousmotorreferstothe()ofthemotor.選項：A、inputapparentpowerB、inputactivepowerC、outputelectricpowerD、mechanicalpoweroutputontheshaft正確答案:【mechanicalpoweroutputontheshaft】3、填空題：1Thespeedofrotatingmagneticfield(synchronousspeed)is()r/min,accordingtotheimformationonthenameplate.正確答案:【1000】Quiz1、問題：Themechanicalcharacteristicsandtheparametersofathree-phaseasynchronousmotor(50Hz,11kW)areshowninthefigure.Iftheloadtorqueis180N×m,then().選項：A、itcanbestarteddirectlyandrunforalongtimeB、itcanbestarteddirectlyandrunforashortti