【MOOC】Electrotechnics Ⅰ (Electrical Technology)-Dalian University of Technology 中國大學(xué)慕課MOOC答案

【MOOC】ElectrotechnicsⅠ(ElectricalTechnology)-DalianUniversityofTechnology中國大學(xué)慕課MOOC答案Quiz1、【單選題】Adevicethatsupplieselectricalenergyorsignals.Itiscalled().本題答案：【source】2、【單選題】Whichoneofthefollowingisnotasignalcircuit().本題答案：【powerdistributing】3、【單選題】Thecircuitinthefigureisasimpletemperaturemeasuringcircuit.Itisa()circuit.本題答案：【signalcircuit】4、【單選題】Whichofthefollowingisanactivetwo-terminalnetwork?().本題答案：【】5、【多選題】Whatdoesitusuallymeanwhenwesaytheloadincreases?本題答案：【power#current】6、【多選題】WhichofthefollowingisnotAC?本題答案：【#】Quiz1、【單選題】Whatisthepotentialofpointb?().本題答案：【2V】2、【單選題】Whatisthepotentialofpointb?().本題答案：【-6V】3、【單選題】Workdonebynon-electricfieldtomoveaunitchargethroughthesource.()本題答案：【EMF】4、【單選題】Whatisthepowerconsumedbythebulbwithacurrentof1.6Awhenavoltageof6Visconnectedacrossit?().本題答案：【9.6W】Quiz1、【單選題】GiventhatUS=100V，terminalvoltageR0=10ohm,currentI=4A，F(xiàn)indthepowerprovidedbythesourceP(Poweroutput)?本題答案：【240W】Quiz1、【單選題】Findthepotentialofpointa.本題答案：【2V】Quiz1、【單選題】Findoutwhichonewillabsorbpower?本題答案：【Onlythevoltagesource】Quiz1、【單選題】thevoltagesourceandthecurrentsourcecanbeconvertedtoeachother.ThenfindIs.().本題答案：【3A】Quiz1、【單選題】FindtheterminalvoltageU().本題答案：【U=Us-IR】2、【單選題】FindtheterminalvoltageU().本題答案：【U=-Us+IR】3、【單選題】Thenumberofbranchesis().本題答案：【4】4、【單選題】Thenumberofbranchesis().本題答案：【6】Quiz1、【填空題】Acircuithas3nodesand7branches.Thenumberofcurrentequationsandvoltageequationsshouldbelistedrespectivelywhenusingbranchcurrentmethodtosolvethecurrentofeachbranch.Thenumberofthevoltageequationsis().本題答案：【5】2、【填空題】FindI=()A.本題答案：【5】Quiz1、【單選題】FindIbysuperpositiontheorem.本題答案：【4A】Quiz1、【單選題】FindIbyThévenin'sTheorem().本題答案：【1A】AssignmentsforChapterOneAssignmentsforChapterOne-2TestforChapterOne1、【單選題】InthecircuitshowninthefollowingFigure.WhentheresistanceR2increases,thecurrentIwill().本題答案：【increase】2、【單選題】InthecircuitshowninthefollowingFigure,thevoltagebetweentheAandB,ＵABis（）.本題答案：【-2V】3、【單選題】InthecircuitshowninthefollowingFigure.WhentheresistanceR1increases,thevoltageＵ2will（）.本題答案：【remainthesame】4、【單選題】FindthevoltageＵ=()V.本題答案：【15V】5、【單選題】Findthecircuitelementsthatprovidepower().本題答案：【currentsource】6、【單選題】InthecircuitshowninthefollowingFigure.I=().本題答案：【2A】7、【單選題】GiventhatU=2V,findthepowergeneratedbythevoltagesourcePs=().本題答案：【2.4W】8、【單選題】InthecircuitshowninthefollowingFigure.UAB=().本題答案：【1V】9、【單選題】InthecircuitshowninthefollowingFigure.I=().本題答案：【2A】10、【單選題】Findtherightexpression.()本題答案：【】11、【單選題】FindU=().本題答案：【-2V】12、【單選題】GiventhatU=0.FindUS=().本題答案：【40V】13、【單選題】Whatisthemeaningoftheloadin“LoadDecrease”?本題答案：【power】14、【單選題】FindthepotentialofA.本題答案：【8V】15、【單選題】FindtheterminalvoltageU=().本題答案：【-18V】16、【填空題】FindI=()A本題答案：【1】17、【填空題】FindUoc=()V.本題答案：【-8】18、【填空題】FindI=()A.本題答案：【4.8】19、【填空題】FindI=()A.本題答案：【3】20、【填空題】FindUoc=()V.本題答案：【2】21、【填空題】FindI=()A.本題答案：【2】22、【填空題】FindtheequivalentresistanceRab=()ohm.本題答案：【4】23、【填空題】FindI=()A.本題答案：【2】24、【填空題】FindI=()A.本題答案：【1】25、【填空題】FindＵab=()V,whentheswitchisopen.本題答案：【5】Quiz1、【判斷題】Ifthevoltageacrosstheinductoriszero,thestoredenergyiszero.本題答案：【錯(cuò)誤】2、【判斷題】Iftheswitchisclosedatt=0,therewillbeatransientprocess.本題答案：【錯(cuò)誤】Quiz1、【單選題】Thecircuitisstable.Theswitchisclosedatt=0.Theni(0+)is().本題答案：【2A】Quiz1、【判斷題】Thefollowingcircuitisafirstordercircuit.本題答案：【錯(cuò)誤】2、【判斷題】Thefollowingcircuitisafirstordercircuit.本題答案：【正確】Quiz1、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Theni(0+)=().本題答案：【0A】2、【單選題】Thecircuitisstablebeforeswitching(noenerystorage).Theswitchisclosedatt=0.Theni(0+)is().本題答案：【0A】Quiz1、【單選題】Thecircuitisstable.Theswitchisclosedatt=0.Thenthetimeconstantis().本題答案：【0.2s】2、【單選題】Theswitchisclosedatt=0.Thenthesteadystatevalueuis().本題答案：【3V】Quiz1、【單選題】Theswitchisthrownfromatobatt=0,thenthetypeofresponseis().本題答案：【Completeresponse】2、【單選題】TheswitchisthrownfromAtoBatt=0,thenthetypeofresponseis().本題答案：【Zero-inputresponse】AssignmentsforChapterTwoTestforChapterTwo1、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstant=().本題答案：【1.8s】2、【單選題】Thecircuitisstable.ThenI=().本題答案：【2A】3、【單選題】Thecircuitisstable.ThenI=().本題答案：【2A】4、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstantis().本題答案：【1s】5、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstantis().本題答案：【0.2s】6、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thenthetimeconstantis().本題答案：【2s】7、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Thentheinitialvalueofthevoltageacrosstheresistorof3is().本題答案：【9V】8、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.ThenthesteadystateofuCis().本題答案：【15V】9、【單選題】Thecircuitisstablebeforeswitching.Theswitchisopenatt=0.Theni(0+)is().本題答案：【1.2A】10、【單選題】Thecircuitisstablebeforeswitching.Theswitchisopenatt=0.Thenthetimeconstantis().本題答案：【1.5s】11、【單選題】Thecircuitisstablebeforeswitching.Theswitchisthrowntopoatt=0.Thenthetimeconstantis().本題答案：【0.2s】12、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.ThenuL(0+)=().本題答案：【-12V】13、【單選題】Thecircuitisstablebeforeswitching.Theswitchisthrownfrom1to2att=0.TheniC(0+)=().本題答案：【3A】14、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.TheniC(0+)=().本題答案：【15mA】15、【單選題】Thecircuitisstablebeforeswitching.Theswitchisthrownfrom1to2att=0.ThenthesteadystatevalueofuC=().本題答案：【0V】16、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0,thenthetimeconstantis().本題答案：【0.1s】17、【單選題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0,thenthetimeconstantis().本題答案：【0.1s】18、【填空題】GiventhatuC(0-)=30V.Theswitchisclosedatt=0.ThenuL(0+)=()V.本題答案：【10】19、【填空題】Thecircuitisstablebeforeswitching.Theswitchisopenatt=0,thenthetimeconstantis()s.本題答案：【1】20、【填空題】Thecircuitisstablebeforeswitching.Theswitchisopenatt=0.Findu(0+)=()V.本題答案：【8】21、【填空題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.Findi2(0+)=()A.本題答案：【1】22、【填空題】Thecircuitisstablebeforeswitching.Theswitchisclosedatt=0.ThenuL(0+)=()V.本題答案：【8】Quiz1、【單選題】Giventhati=10sin（1000t–70°）A.Findtheinitialphase().本題答案：【–70°】2、【單選題】Giventhati=10sin（1000t–70°）A.Theeffectivevalueofthecurrentis()A.本題答案：【7.07】3、【單選題】Theunitofangularfrequencyis().本題答案：【rad/s】Quiz1、【單選題】本題答案：【】Quiz1、【單選題】本題答案：【5】Quiz1、【單選題】Giventhatu=14.14sin314tV,C=140μF,thentheeffectivevalueofthecurrentiisabout()A.本題答案：【0.44】Quiz1、【單選題】本題答案：【25】2、【填空題】Thereadingofthevoltmeteris()V.本題答案：【5】3、【填空題】Thereadingofthevoltmeteris()V.本題答案：【10】Quiz1、【填空題】FindtheeffectivevalueofthecurrentI=()A.本題答案：【(21,23)】Quiz1、【填空題】Thereadingoftheammeteris()A.本題答案：【5】2、【填空題】Thereadingoftheammeteris()A.本題答案：【4】3、【填空題】Findthetotalimpedance().本題答案：【10】Quiz1、【單選題】InaseriesRLCACcircuit,ifthecurrentinthecircuitisI,thetotalvoltageisU,theactivepowerisP,thereactivepowerisQ,andtheapparentpowerS,thentheimpedanceis().本題答案：【】2、【單選題】InaseriesRLCACcircuit,theactive(average)powerP=().本題答案：【】Quiz1、【單選題】本題答案：【】2、【單選題】Inordertoimprovethepowerfactorofinductiveloadcircuit,thecommonlyusedmethodis（).本題答案：【Parallelcapacitance】AssignmentsforChapterThreeAssignmentsforChapterThree-2TestforChapterThree1、【單選題】Findtheinitialphaseofu().本題答案：【–90°】2、【單選題】Giventhati=100sin（314t－30°）A,u=311sin（314t+60°）VFindthephasedifferencebetweenuandi().本題答案：【90°】3、【單選題】SeriesRLCACcircuit.GiventhatXL=XC=20Ω，R=10Ω，theeffectivevalueoftotalvoltageis220V.Thentheeffectivevalueofthevoltageacrossthecapacitoris().本題答案：【440V】4、【單選題】Twosinusoidalalternatingcurrentsi1andi2.I1=I2=4A.Thetotalcurrenti=i1+i2.Theeffectivevalueofthetotalcurrentisstill4A,thenthephasedifferencebetweenthemis().本題答案：【120°】5、【單選題】WhensinusoidalACcurrentpassesthrougharesistiveelement,whichofthefollowingrelationiscorrect().本題答案：【】6、【單選題】Inapureinductivecircuit,iftheinitialphaseofcurrentis-60°,thentheinitialphaseofvoltageis().本題答案：【30°】7、【單選題】Inacapacitivecircuit.XC=100Ω.Thevoltageacrossthecapacitoris,thenitscurrentshouldbe().本題答案：【】8、【單選題】hesamecoil(canbeseenasaresistorconnectedinserieswithandinductor)isconnectedtoDCandACpowersupplyrespectively.ThentheinductivereactanceXLis()Ω.本題答案：【16】9、【單選題】Whichoneisright?()本題答案：【uilagsuo】10、【單選題】Thereadingofthevoltmeteris()V.本題答案：【32】11、【單選題】ThephasordiagramofterminalvoltageandcurrentisshownintheFigure.Thecircuitexhibit()characteristics.本題答案：【capacitive】12、【單選題】SeriesRLCACcircuit，F(xiàn)indtherightexpressionof（）.本題答案：【】13、【單選題】InanACcircuit,thevoltageappliedacrossthecircuitis本題答案：【0】14、【單選題】Thepowersourcesinthethreecircuitsarethesame,thebulbsarethesameandcanemitlight,whichbulbisthebrightest?()本題答案：【】15、【單選題】Acoilandacapacitorareconnectedinseries.GiventhatR=4Ω，XL=3Ω，u=220sin(314t+π/4)V，i=44sin(314t+84°)A.ThenXC=()Ω本題答案：【6】16、【單選題】GiventhatR=60Ω,C=125μF,.Thentheeffectivevalueofiis().本題答案：【1.1】17、【單選題】TheACpowersupplyvoltageremainsunchanged.Whenthefrequencydecreases,thevoltmeterreadingwill().本題答案：【decrease】18、【單選題】Findthetotalimpedance().本題答案：【】19、【單選題】Anincandescentlampisconnectedinserieswithacapacitor.TheACpowersupplyvoltageremainsunchanged.Whenthefrequencydecreases,thecapacitivereactanceXCwill().本題答案：【increase】20、【單選題】Ginventhat本題答案：【】21、【單選題】Whichofthefollowingisnotright?()本題答案：【】22、【填空題】Thereadingofthevoltmeteris()V.本題答案：【5】23、【填空題】SeriesRLCcircuit,Givethat:URL=100V,UC=60V,Thetotalvoltageandthetotalcurrentisinphase.Thenthetotalvoltageis()V.本題答案：【80】24、【填空題】本題答案：【10】25、【填空題】GiventhatR=20Ω,L=48mH,本題答案：【(8,9)】Quiz1、【單選題】Thethree-phase?-connectedgeneratorisdrivingabalancedloadsuchthateachphasecurrentis10Ainmagnitude.When=10∠30°A,then=().本題答案：【17.3∠120°A】2、【單選題】Inacertainthree-wire,Y-connectedgenerator,thephasevoltagesare1.0kV.themagnitudeofthelinevoltagesis（）kV.本題答案：【1.732】3、【單選題】Inathree-phasesystem,thevoltagesareseparatedby().本題答案：【120】Quiz1、【單選題】Ifthesourcelinevoltagesare380V,Y-connectedload,themagnitudeoftheloadlinevoltagesis().本題答案：【380V】2、【單選題】AcertainY-connectedsourceproducesphasecurrentsof15A.iftheloadisY-connected,eachloadphasecurrentis().本題答案：【15.0A】3、【單選題】AY-connectedsourcedrivinga?-connectedload.Thelinevoltagesofsourceare380V,eachimpedanceofabalancedthree-phaseloadis85.6+j50.Theloadlinecurrentsare()A..本題答案：【6.6】Quiz1、【單選題】=30V,=1.2A,andthepowerfactoris0.257.ThetotalapparentpowerinabalancedY-connectedloadis().本題答案：【62.35VA】2、【單選題】Theaveragepowerineachphaseofabalancedthree-phasesystemis1,200W,andthetotalpoweris().本題答案：【3600W】3、【單選題】InacertainY-connectedbalancedload,thelinevoltagesare380Vandtheimpedancesare30+j40?.thetotalreactivepoweris().本題答案：【2.316kvar】AssignmentsforChapterFourTeatforChapterFour1、【單選題】Twomajorpartsofanacgeneratorare().本題答案：【rotorandstator】2、【單選題】Thephasecurrentproducedbyacertain240V,Y-connectedgeneratoris12A.Thecorrespondinglinecurrentis().本題答案：【12A】3、【單選題】Acertain?-connectedgeneratorproducesphasevoltagesof30V.Themagnitudeofthelinevoltagesare().本題答案：【30V】4、【單選題】Ifthesourcephasevoltagesofa?-Ysystem（A?-connectedsourcedrivingaY-connectedload）are220V,themagnitudeoftheloadphasevoltagesis（）.本題答案：【127V】5、【單選題】Abalanced,three-phase,-connectedloadhasalinevoltageof200Vandatotalpowerconsumptionof4800Watalaggingpowerfactorof0.8.Thephasecurrentofeachloadis().本題答案：【10A】6、【判斷題】Voltagesacrossthegeneratorwindingsarecalledlinevoltages本題答案：【錯(cuò)誤】7、【判斷題】AY-connectedsystemcanhaveeitherthreeorfourwires.本題答案：【正確】8、【判斷題】Ina?-connectedgeneratorthelinecurrentsandthephasecurrentsareequal.本題答案：【錯(cuò)誤】9、【判斷題】Inabalancedsystemtheneutrallinecanberemoved.本題答案：【正確】10、【判斷題】Inacertain?-connectedbalancedload,thelinevoltagesare250Vandtheimpedancesare50∠30°?.thetotalapparentpoweris3.75kVA.本題答案：【正確】Quiz1、【單選題】TheunitofMagneticfluxis().本題答案：【W(wǎng)b】2、【單選題】MagneticFluxperunitofcross-sectionalareais().本題答案：【MagneticFluxDensity】3、【判斷題】MagneticFluxDensityBisavector.WhileMagneticFieldIntensityHisnotavector.本題答案：【錯(cuò)誤】4、【判斷題】MagneticFluxDensityBdependsonboththecurrentandmaterialproperties.本題答案：【正確】Quiz1、【單選題】Whatisthemeaningof?本題答案：【Leakageflux】2、【單選題】Whatisthemeaningof?本題答案：【Remanence】3、【單選題】Whichoneissoftmaterialaccordingtothehysteresisloopsoffourdifferentmagneticmaterials?本題答案：【】4、【單選題】Aclosedpathfollowedbymainmagneticfluxisknownasa().本題答案：【Magneticcircuit】5、【單選題】ThechangeofBalwayslagsbehindthechangeofH.Thisphenomenoniscalled().本題答案：【Hysteresis】Quiz1、【單選題】Whatisthemeaningof?本題答案：【Permeabilityoftheairgap】2、【單選題】TheequivalentofthecurrentIinmagneticohm'slawis()?本題答案：【Flux】3、【單選題】WhatisMMF?本題答案：【MagnetomotiveForce】4、【單選題】WhathappenstotheMMFwhenthemagneticfluxdecreases?本題答案：【Decreases】Quiz1、【單選題】WhichoneisnotthemajorpartofElectromagnet?本題答案：【rotor】Quiz1、【單選題】GiventhatthemagneticcircuitofDCelectromagnet.ThevoltageUisconstant.HowwillthecoilcurrentIchangewhentheairgaplengthincreases().本題答案：【remainunchanged】2、【單選題】GiventhatthemagneticcircuitofDCelectromagnet.ThevoltageUisconstant.HowwilltheMagneticfluxchangewhentheairgaplengthincreases().本題答案：【decrease】Quiz1、【單選題】GiventhatthemagneticcircuitofACelectromagnet.ThevoltageUisconstant.HowwillthecoilcurrentIchangewhentheairgaplengthincreases().本題答案：【increase】2、【單選題】GiventhatthemagneticcircuitofACelectromagnet.ThevoltageUisconstant.HowwilltheMagneticfluxchangewhentheairgaplengthincreases().本題答案：【remainunchanged】Quiz1、【單選題】Whichofthefollowingplaysaroleintransmittingelectricenergyinthetransformer（）.本題答案：【Mainmagneticflux】2、【單選題】Theworkingprincipleoftransformerisbasedon（）.本題答案：【Faraday’slawofelectromagneticinduction】Quiz1、【單選題】Theexternalcharacteristicofpowertransformerisrelatedtothenatureofload.Whentheloadisinductive,itsexternalcharacteristiccurvewillbe（）.本題答案：【】2、【單選題】Theratedcapacityofasingle-phasetransformerisSN=50kV·A,theno-loadcurrentI0is3%oftheratedcurrent,theratedvoltagesare10kV/230V,thesecondarysidevoltageatfullloadis220V,FindthevoltageregulationVR.（）.本題答案：【4.35%】Quiz1、【單選題】Whenthereisaload,themainmagneticfluxofthetransformerisgeneratedby().本題答案：【PrimarycurrentI1andSecondarycurrentI2together】2、【單選題】Atransformerisoperatingatnoloadconditionwithratedvoltageof220Vappliedtotheprimaryside,andtheresistanceoftheprimarywindingismeasuredas10.Trytofindtheprimarycurrent().本題答案：【Approximateto0A】Quiz1、【單選題】AloadwithRL=8isconnectedtoasignalsourcethroughatransformer,theinternalresistanceR0ofthesignalsourceis800,andthenumberofturnsN1oftheprimarywindingofthetransformeris1000.iftheloadgetsthemaximumpowerthroughimpedancematching,thenumberofturnsN2ofthesecondarywindingofthetransformershouldbe().本題答案：【100】Quiz1、【單選題】A10kV·Atransformersuppliespowertoaloadwithapowerfactorof0.8infullload.Giventhatthecorelossis300W,thecopperlossis400W.Ignorethevoltageregulation.Findtheefficiencyofthetransformer().本題答案：【92%】Quiz1、【單選題】Thesiliconsteelsheetusedintransformercoreismaterial().本題答案：【】AssignmentsforChapterFiveTestforChapterFive1、【單選題】TwoidenticalACironcore-windingsarepoweredbytwovoltagesources.Thevoltagesofthetwopowersourcesarethesamewhilethefrequenciesaredifferent(f1f2),thenwhichfollowingdescriptionisrightabout1()2.本題答案：【】2、【單選題】ForDCcorecoil,whenthenumberofturnsNofthecoilisdoubled,thenthemagneticfluxwill（）.本題答案：【increase】3、【單選題】ForanACcorecoil,whenthecorecross-sectionalareaAisdoubled,themagneticfluxwill().本題答案：【remainunchanged】4、【單選題】ADCelectromagnetwithratedvoltageof100VisconnectedtoanACpowersupplywithvoltageof100V.CoilcurrentIwill().本題答案：【decrease】5、【單選題】ADCelectromagnetwithratedvoltageof100VisconnectedtoanACpowersupplywithvoltageof100V.Magneticfluxthroughthecoilwill().本題答案：【decrease】6、【單選題】Therelationshipbetweencopperlossofatransformeris().本題答案：【proportionaltoloadcurrentsquared】7、【單選題】Therelationshipbetweenironlossofatransformerandtheload().本題答案：【Ithasnothingtodowiththeloadandremainsunchanged】8、【單選題】AloadRL=8isconnectedtoasignalsourcethroughatransformer.TheinternalresistanceR0ofthesignalsourceis800,andthenumberofturnsoftheprimarywindingN1is1000.Iftheloadgetsthemaximumpowerthroughimpedancematching,thenthenumberofturnsofthesecondarywindingN2shouldbe().本題答案：【100】9、【單選題】Asingle-phasetransformerwithratedcapacityofSN=50kV?Aandtheratedvoltageof10kV/230V.Giventhattheno-loadcurrentI0is3%ofratedcurrentandtheoutputvoltageatfullloadis220V.Thenthevoltageregulationis().本題答案：【4.35%】10、【單選題】Forcapacitiveload,whenthecurrentonthesecondarysideincreases,theoutputvoltageonthesecondarysidewill().本題答案：【increase】11、【填空題】ACelectromagnet,IfUandfremainthesame.Thecurrentiwill(increase/reduce/unchanged)whentheairgapisdecreased.本題答案：【reduce】12、【填空題】Atransformerisusedforimpedancematching.Theresistanceofthespeakershouldbeincreasedfrom4Ωto100Ωinordertoconnectproperlywiththeamplifier.Howmuchistheimpedancetransformationratio.本題答案：【5】13、【填空題】TwoidenticalACironcore-windingsarepoweredbytwovoltagesources.Thevoltagesofthetwopowersourcesarethesamewhilethenumberofturnsaredifferent(N1N2),then12.(,,=)本題答案：【<】14、【填空題】A50kV·Asingle-phasetransformerwhichratedvoltageis6600/230V.cosφ2=0.8.Giventhatthecorelossis600W,thecopperlossis1500W.U2=220V(full-loading).Findtheefficiencyofthetransformer(full-loading).%本題答案：【(94,95)】15、【填空題】Asingle-phasetransformerwithacapacityof50kV×Aandratedvoltageof3300/220V.Thetransformerisoperatingatitsratedcapacity.Iffluorescentlamps(40W,220V)withpowerfactorof0.5areusedonthesecondaryside,howmanylampscanbeconnectedalltogether(ignorethelossofballast).本題答案：【625】Quiz1、【單選題】WhichoneisnotthemajortypeOfasynchronousmotorbasedontypeoftherotorwinding?()本題答案：【Powersynchronousrotor】2、【單選題】What’sthenameofthemotorcomponentinthepicture().本題答案：【Rotor】3、【單選題】Whichoneofthefollowingisnotawoundrotor?()本題答案：【】4、【單選題】Asynchronousmotorisalsocalled()?本題答案：【Inductionmotor】Quiz1、【單選題】Findthesynchronousspeedofthemotorwhosestatorcoreisshowninthepicture.()本題答案：【750r/min】2、【單選題】Whatarethesynchronousspeedswhenthepairsofpolesis3atafrequencyof60Hz?()本題答案：【1200r/min】Quiz1、【單選題】Themaximumtorqueofthree-phaseasynchronousmotoris().本題答案：【proportionaltothevoltagesquared】2、【單選題】Athree-phaseasynchronousmotorwithratedspeedof1450r/min.Findthepairsofpoles().本題答案：【2】3、【單選題】Whatisthevalueofslipatthemomentofstarting?()本題答案：【1】Quiz1、【單選題】Theoutputpowerofathree-phaseasynchronousis().本題答案：【Mechanicalpower】2、【單選題】Findtheunitoftorque().本題答案：【N·m】Quiz1、【單選題】Thepowerinput(electricpower)ofthemotoris()kW.本題答案：【3.58】2、【單選題】Theratedpowerofthree-phaseasynchronousmotorreferstothe()ofthemotor.本題答案：【mechanicalpoweroutputontheshaft】3、【填空題】1Thespeedofrotatingmagneticfield(synchronousspeed)is()r/min,accordingtotheimformationonthenameplate.本題答案：【1000】Quiz1、【單選題】Themechanicalcharacteristicsandtheparametersofathree-phaseasynchronousmotor(50Hz,11kW)areshowninthefigure.Iftheloadtorqueis180N×m,then().本題答案：【itcanbestarteddirectlyandrunforashorttime,butnotfitforlongtermrunning】2、【填空題】Themaximumtorqueofthethree-phaseasynchronousmotoris900N·m,andtheratedtorqueis450N·m,thentheoverloadcoefficientofthemotoris().本題答案：【2】3、【填空題】Thestatorlinevoltageofathree-phaseasynchronousmotordecreasesby10%comparedwiththeratedvoltage,anditstorquedecreasesbyabout()%comparedwiththeratedtorqueratio.本題答案：【20】Quiz1、【單選題】WhichoneisrightabouttheY-△startingofthree-phaseasynchronousmotor().本題答案：【Thestatorphasevoltageisreducedbutthelinevoltageremainsunchanged】2、【單選題】Whichoneisrightabouttheautotransformerstartingofathree-phaseasynchronousmotor().本題答案：【Thelinevoltageandphasevoltageofthestatorarereducedatthesametime】Quiz1、【單選題】WhenVVVFspeedcontrolmethodisusedforthespeedcontrolofathree-phaseasynchronousmotor.IftheoutputvoltageandfrequencyoftheVVVFdrivesystemarereduced,thespeedwill().本題答案：【decrease】AssignmentsforChapterSixTestforChapterSix1、【單選題】Findtheslips()accordingtothenameplate.本題答案：【0.04】2、【單選題】Thedifferencebetweencage-typeasynchronousmotorandwound-typeasynchronousmotorismainlyin().本題答案：【Rotorwinding】3、【單選題】Electromagnetictorqueofathree-phaseasynchronousmotorisproducedbytheinteractionbetween().本題答案：【rotatingmagneticfieldandtheactivecomponentsofrotorcurrent】4、【單選題】Ifthefrequencyis60Hz.Giventhepa