【MOOC】College Physics I-Dalian University of Technology 中國大學慕課MOOC答案

【MOOC】CollegePhysicsI-DalianUniversityofTechnology中國大學慕課MOOC答案Pre-coursepreparation1、【判斷題】Velocityinphysicsisthespeedofanobject.本題答案：【錯誤】2、【判斷題】Accelerationisdefinedasavectorquantitythatindicatestherateofchangeofvelocity.本題答案：【正確】3、【判斷題】Distanceanddisplacementaretwoquantitiesthatmayseemtomeanthesamethingyethavedifferentdefinitionsandmeanings.本題答案：【正確】UnitTest11、【單選題】Whichofthefollowingisavectorquantity:本題答案：【acceleration】2、【單選題】Inrighthandedcoordinatesystemwhichaxisisconsideredtobepositive?本題答案：【Thethumbisz-axis,fingerscurledfromx-axistoy-axis】3、【單選題】WhatisthemagnitudeoftheCartesianvectorhavingthex,yandzaxiscomponentstobeA,BandC?本題答案：【SquarerootofthesquareseachA,BandC】4、【單選題】Theradialcomponentofvelocityforaparticlemovinginacircularpathis______.本題答案：【Zero】5、【單選題】Whenaccelerationis_______,avelocityofaparticleisconstant.本題答案：【Zero】6、【單選題】Ablockslidingdownaninclinedplanehasacceleration_________accelerationduetogravity.本題答案：【Lessthan】7、【單選題】Aphysicsprofessorleavesherhouseandwalksalongthesidewalktowardcampus.After5minitstartstorainandshereturnshome.HerdistancefromherhouseasafunctionoftimeisshowninFig.AtPoint_________(fillinthelabeledpointsI/II/III/IV/V)ishervelocityzero.本題答案：【IV】8、【單選題】Aphysicsprofessorleavesherhouseandwalksalongthesidewalktowardcampus.After5minitstartstorainandshereturnshome.HerdistancefromherhouseasafunctionoftimeisshowninFig.AtPoint_________(fillinthelabeledpointsI/II/III/IV/V)ishervelocityincreasinginmagnitude.本題答案：【II】9、【單選題】Amodelofahelicopterrotorhasfourblades,each3.40mlongfromthecentralshafttothebladetip.Themodelisrotatedinawindtunnelat550rev/min.Thelinearspeedofthebladetipis________m/s.本題答案：【196m/s】10、【單選題】AnastronauthaslefttheInternationalSpaceStationtotestanewspacescooter.Herpartnermeasuresthefollowingvelocitychanges,takingplaceina10sinterval.Atthebeginningsheismovingtowardtherightat15.0m/s,andattheendsheismovingtowardtheleftat15.0m/s.Themagnitudeofheraverageaccelerationis________m/s^2.本題答案：【3】11、【單選題】Abodythat’smovingwithaconstantspeedtravelsoncearoundacircularpath.Whichofthefollowingis/aretrueconcerningthemotion?I.Thedisplacementiszero.II.Theaveragespeediszero.III.Theaccelerationiszero.本題答案：【Ionly】12、【單選題】Arockisthrownoffa35mcliffata45°angleabovethehorizontal.Whichisthefollowingistrueregardingtheaccelerationoftherock?本題答案：【Theaccelerationwillbeofmagnitudegandinadownwarddirection.】13、【單選題】Asmallstoneisthrownhorizontallywithaninitialspeedof30m/sfromabridge.Findthestone’stotalspeedwhenitentersthewater4secondslater.(Ignoreairresistance.)本題答案：【50m/s】14、【單選題】Whichoneofthefollowingstatementsistrueconcerningthemotionofanidealprojectilelaunchedatanangleof45°tothehorizontal?本題答案：【Theverticalspeeddecreasesonthewayupandincreasesonthewaydown.】15、【單選題】Thepositionofanobjectmovinginastraightlineisgivenbytheequationx=(3t3+7t+5)m,wheretisinseconds.Whatistheobject’saccelerationattimet=5seconds?本題答案：【90m/s2】16、【單選題】Theearthhasaradiusof6380kmandturnsaroundonceonitsaxisin24h.Whatistheradialaccelerationofanobjectattheearth’sequator?_______m/s2本題答案：【0.034】17、【單選題】Theearthhasaradiusof6380kmandturnsaroundonceonitsaxisin24h.Ifaradattheequatorisgreaterthang,objectswillflyofftheearth’ssurfaceandintospace.Whatwouldtheperiodoftheearth’srotationhavetobeforthistooccur?本題答案：【5070S#1.4h】18、【單選題】Aballisprojectedwithaninitialvelocityofmagnitudev0=40m/stowardaverticalwallasshowninthefigure.Howlongdoestheballtaketoreachthewall?______S本題答案：【1.0】19、【單選題】Twoprojectilesarelaunchedat100m/s,theangleofelevationforthefirstbeing30°andforthesecond60°.Whichofthefollowingstatementsisfalse?本題答案：【Alloftheotherstatementsarefalse.】20、【單選題】PlaneAisflyingat400mphinthenortheastdirectionrelativetotheearth.PlaneBisflyingat500mphinthenorthdirectionrelativetotheearth.WhatisthespeedofPlaneBasobservedfromPlaneA?本題答案：【357mph】Pre-coursepreparation1、【判斷題】Equilibriumistheconditionofasystemwhenneitheritsstateofmotionnoritsinternalenergystatetendstochangewithtime.本題答案：【正確】2、【判斷題】Todescribeaforce,weonlyneedtodescribethemagnitudethatdescribehowhardtheforcepushesorpulls.本題答案：【錯誤】3、【判斷題】Inclassicalmechanicskinematicsgenerallyreferstothestudyofpropertiesofmotion--position,velocity,acceleration.Dynamicsisthestudyofthephysicsofmotionandhowitrelatestoappliedforces.本題答案：【正確】UnitTest21、【單選題】Ifanobjectisinequilibrium,whichofthefollowingstatementsisnottrue?本題答案：【Theobjectmustbeatrest.】2、【單選題】Twoblocks,joinedbyastring,havemassesof6.0kgand9.0kg.Theyrestonafrictionlesshorizontalsurface.Asecondstring,attachedonlytothe9kgblock,hashorizontalforce=30Nappliedtoit.Bothblocksaccelerate.Findthetensioninthestringbetweentheblocks.本題答案：【12N】3、【單選題】Ifanobjectofmassmmoveswithconstantvelocityv,thenetforceontheobjectis本題答案：【0】4、【單選題】Alargecrateofmassmisplacedonthebackofatruckbutnottieddown.Asthetruckacceleratesforwardwithanaccelerationa,thecrateremainsatrestrelativetothetruck.Whatforcecausesthecratetoaccelerateforward?本題答案：【theforceoffrictionbetweenthecrateandthefloorofthetruck】5、【單選題】Ifduringagivenphysicalprocesstheonlyforceactingonanobjectisfriction,whichofthefollowingmustbeassumedinregardtotheobject'skineticenergy?本題答案：【Itcannotbedeterminedfromtheinformationgiven】6、【單選題】Whichofthefollowingisthatformofenergyassociatedwithanobject'smotion?本題答案：【Kinetic】7、【單選題】Theworkdonebystaticfrictioncanbe:本題答案：【Anyoftheothers】8、【單選題】Thequantityofworkequaltoonejouleisalsoequivalenttowhichofthefollowing?本題答案：【W(wǎng)att?s】9、【判斷題】OnekilogramofgoldwouldhavegreatervalueonEarththanontheMoon.本題答案：【錯誤】10、【判斷題】Anobjectcanmoveevenwhennoforceactsonit.本題答案：【正確】Pre-Coursepreparation1、【判斷題】Workisascalarquantity,eventhoughit'scalculatedbyusingtwovectorquantities(forceanddisplacement).本題答案：【正確】2、【判斷題】Workandpoweraresamethingsincebothoftheminvolvetheamountofenergytransferred.本題答案：【錯誤】3、【判斷題】Conservationmeansthepreservationofaphysicalquantityduringtransformationsorreactions.本題答案：【正確】Unittest31、【單選題】Aboycaughtaballofmass200gmovingwithaspeedof30m/s.Ifthecatchingprocessbecompletedin0.1s,theaveragenetforceofimpactexertedbytheballonthehandsoftheboyis本題答案：【60N】2、【單選題】AlexandJohnareloadingidenticalcabinetsontoatruck.Alexliftshiscabinetstraightupfromthegroundtothebedofthetruck,whereasJohnslideshiscabinetuparoughramptothetruck.Whichstatementiscorrectabouttheworkdoneonthecabinet–Earthsystem?本題答案：【JohndoesmoreworkthanAlex.】3、【單選題】Aballofclayfallsfreelytothehardfloor.Itdoesnotbouncenoticeably,anditveryquicklycomestorest.What,then,hashappenedtotheenergytheballhadwhileitwasfalling?本題答案：【Itisintheballandfloor(andwalls)asenergyofinvisiblemolecularmotion.】4、【單選題】Iftwoparticleshaveequalmomentum,aretheirkineticenergiesequal?本題答案：【no,exceptwhentheirspeedsarethesame】5、【單選題】Anatomicnucleussuddenlyburstsapart(fissions)intotwopieces.Onepiecetravelsoffthetheleftandanotherpiecetravelsofftotheright.Thelighterfragmenthas________speed.本題答案：【greater】6、【單選題】Atoneinstant,thecenterofmassofasystemoftwoparticlesislocatedonthex-axisatx=2.0m.Oneoftheparticlesisattheorigin.Theotherparticlehasamassof0.10kgandisatrestonthex-axisatx=8.0m.Themassoftheparticleattheoriginis(kg).本題答案：【0.3】7、【單選題】Idropa60-ggolfballfrom2.0mhigh.Itreboundsto1.5m.Howmuchenergyislost?本題答案：【0.29J】8、【單選題】Agirlandherbicyclehaveatotalmassof40kg.Atthetopofthehillherspeedis5.0m/s.Thehillis10mhighand100mlong.Iftheforceoffrictionassheridesdownthehillis20N,whatisherspeedatthebottom?本題答案：【11m/s】9、【單選題】Ablockisprojectedwithspeedvacrossahorizontalsurfaceandslidestoastopduetofriction.Thesameblockisthenprojectedwiththesamespeedvupaninclinewhereisslidestoastopduetofriction.Inwhichcasedidthetotalmechanicalenergyoftheblockdecreasetheleast?本題答案：【Thecaseontheinclinedsurfacehadtheleastdecreaseintotalmechanicalenergy.】10、【單選題】Whichofthefollowingisanexampleofanonconservativeforce?本題答案：【frictiontionalforce】Pre-coursepreparation1、【判斷題】Abodyissaidtobearigidbody,whenithasperfectlydefiniteshapeandsize.Thedistancebetweenallpointsofparticlesofsuchabodydonotchange,whileapplyinganyforceonit本題答案：【正確】2、【判斷題】Thereare2πradiansinonecompleterevolution.本題答案：【正確】3、【判斷題】Torqueisameasureoftheforcethatcancauseanobjecttorotateaboutanaxis.本題答案：【正確】Unittest41、【單選題】Agrindstoneincreasesinangularspeedfrom4.00rad/sto12.00rad/sin4.00s.Throughwhatangledoesitturnduringthattimeintervaliftheangularaccelerationisconstant?本題答案：【32.0rad】2、【單選題】Consideranobjectonarotatingdiskadistancerfromitscenter,heldinplaceonthediskbystaticfriction.Whichofthefollowingstatementsisnottrueconcerningthisobject?本題答案：【Iftheangularspeedisconstant,theobjectisnotaccelerated.】3、【單選題】Aconstantnettorqueisexertedonanobject.Whichofthefollowingquantitiesfortheobjectcannotbeconstant?本題答案：【kineticenergy】4、【單選題】AsolidaluminumsphereofradiusRhasmomentofinertiaIaboutanaxisthroughitscenter.Willthemomentofinertiaaboutacentralaxisofasolidaluminumsphereofradius2Rbe本題答案：【32I】5、【單選題】Aniceskaterstartsaspinwithherarmsstretchedouttothesides.Shebalancesonthetipofoneskatetoturnwithoutfriction.Shethenpullsherarmsinsothathermomentofinertiadecreasesbyafactorof2.Intheprocessofherdoingso,whathappenstoherkineticenergy?本題答案：【Itincreasesbyafactorof2.】6、【單選題】Consideranisolatedsystemmovingthroughemptyspace.Thesystemconsistsofobjectsthatinteractwitheachotherandcanchangelocationwithrespecttooneanother.Whichofthefollowingquantitiescanchangeintime?本題答案：【Neithertheangularmomentumnorlinearmomentumofthesystem.】7、【單選題】Twoponiesofequalmassareinitiallyatdiametricallyoppositepointsontherimofalargehorizontalturntablethatisturningfreelyonafrictionless,verticalaxlethroughitscenter.Theponiessimultaneouslystartwalkingtowardeachotheracrosstheturntable.Astheywalk,whathappenstotheangularspeedoftheturntable?本題答案：【Itincreases.】8、【單選題】Aturntablerotateswithaconstantangularacceleration.After4.00sithasrotatedthroughanangleof60.0rad.Theangularvelocityofthewheelatthebeginningofthe4.00sintervalwas本題答案：【10.5rad/s】9、【單選題】Asolid,uniformcylinderwithmass8.25kganddiameter15.0cmisspinningat220rpmonathin,frictionlessaxlethatpassesalongthecylinderaxis.Youdesignasimplefrictionbraketostopthecylinderbypressingthebrakeagainsttheouterrimwithanormalforce.Thecoefficientofkineticfrictionbetweenthebrakeandrimis0.333.Whatmusttheappliednormalforcehetobringthecylindertorestafterithasturnedthrough5.25revolutions?本題答案：【7.47N】10、【單選題】Twoparticlesofdifferentmassstartfromrest.Thesamenetforceactsonbothofthemastheymoveoverequaldistances.Howdotheirfinalkineticenergiescompare?本題答案：【Theparticleshaveequalkineticenergies.】Pre-coursepreparation1、【判斷題】RelativitygenerallyreferstotwotheoriesofAlbertEinstein,hisSpecialTheoryofRelativityandhisGeneralTheoryofRelativity.本題答案：【正確】2、【判斷題】Specialrelativitycannotbeappliedtoclassicalmechanicsproblems.本題答案：【錯誤】3、【判斷題】SpecialtheoryofrelativitybyEinstein(1905)providesextremelyaccurateresultsaslongasthedomainofstudyisrestrictedtolargeobjectsandthespeedsinvolveddonotapproachthespeedoflight.本題答案：【錯誤】Unittest51、【單選題】Inordertoreduceyourthicknessby40%toanobserveratrest,whatisthespeedwithwhichyoumustbemovingrelativetotheobserver?本題答案：【0.8c】2、【單選題】Toappeartobethintoobserversatrest,ayoungmanstartsridingaspacecraft.Toreducehisthicknessexactlybyhalf,thespeedatwhichthespacecraftmustmoveis本題答案：【0.866c】3、【單選題】Inthelaboratoryframeofreference,themomentumofaparticleofrestmassmisfoundtobe4mc/3withcthespeedoflightinvacuum.Whatisthespeedoftheparticleinthelaboratoryframeofreference?本題答案：【4c/5】4、【單選題】Whichstatementiscorrectaboutthespecialrelativity?本題答案：【Thespeedoflighthasnothingtodowiththereferencesystem.】5、【單選題】AspacecraftzoomspasttheEarthwithaconstantvelocity.AnobserverontheEarthmeasuresthatanundamagedclockonthespacecraftistickingatonethirdtherateofanidenticalclockontheEarth.WhatdoesanobserveronthespacecraftmeasureabouttheEarth-basedclock’stickingrate?本題答案：【Itrunsatone-thirdtherateofhisown】6、【單選題】Anastronautistravelinginaspacecraftinouterspaceinastraightlineataconstantspeedof0.500c.Whichofthefollowingeffectswouldsheexperience?本題答案：【Noneofthoseanswersiscorrect.】7、【單選題】Adistantastronomicalobject(aquasar)ismovingawayfromusathalfthespeedoflight.Whatisthespeedofthelightwereceivefromthisquasar?本題答案：【c】8、【單選題】AspacecraftbuiltintheshapeofaspheremovespastanobserverontheEarthwithaspeedof0.500c.Whatshapedoestheobservermeasureforthespacecraftasitgoesby?本題答案：【aroundpillowshape,flattenedalongthedirectionofmotion】9、【多選題】Asacarheadsdownahighwaytravelingataspeedvawayfromagroundobserver,whichofthefollowingstatementsaretrueaboutthemeasuredspeedofthelightbeamfromthecar’sheadlights?Morethanonestatementmaybecorrect.本題答案：【Thedrivermeasuresthelightspeedtobec#Thegroundobservermeasuresthelightspeedtobec】10、【多選題】Whichofthefollowingstatementsarefundamentalpostulatesofthespecialtheoryofrelativity?Morethanonestatementmaybecorrect.本題答案：【Thelawsofphysicsarethesameinallinertialreferenceframes.#Thespeedoflightisindependentoftheinertialreferenceframeinwhichitismeasured.】Pre-coursepreparation1、【判斷題】Anexperimentshowsthatanelectronandapositroncanbeproducedafterahigh-energygammaraycollideswithahydrogenatom.Thisisanexperimentalevidenceforaviolationofprincipleofconservationofcharge.本題答案：【錯誤】2、【判斷題】Atestchargeisapointchargeofaenoughsmallmagnitudeanditcanbeeitherpositiveornegative.本題答案：【正確】3、【判斷題】Anelectricdipoleisapairofpointchargeswithequalmagnitudeandoppositesign(apositivechargeqandanegativecharge-q)separatedbyadistanced.Electricdipolemomentisascalarquantityandisdifinedasqd.本題答案：【錯誤】UnitTest61、【單選題】Electricchargeisdistributeduniformlyalonganinfinitelineinvacuum(thelinearchargedensityis).Theforceonatestchargeatadistancerfromthelineis().(isaunitvector.)本題答案：【】2、【單選題】Anelectricdipolewithdipolemomentisparalleltoalonglineofchargewithlinearchargedensityandatadistancefromtheline.Themagnitudeoftorqueonthedipoleequals().本題答案：【】3、【單選題】TwoparalleplateswithareaAaregivenchargesQuniformly.Theirseparationismuchsmallerthanthedimensionsoftheplatesandthefringingeffectisneglected.Whatisthemagnitudeoftheelectricforceononeplateexertedbytheother?本題答案：【】4、【單選題】Anelectricdipolewithdipolemomentisinauniformelectricfield.Ifthedipoleisinthestableequilibriumstate,whichofthefollowingstatementsiscorrect?本題答案：【Thetorqueiszeroandpotentialenergyisminimum.】5、【單選題】Achargeisplacedattheoriginofacoordinatesystemandachargeislocatedatonthex-axis.Theforceonisfoundtobe.Athirdchargeisnowplacedatonthex-axis.Whatisthenetforceonnow?本題答案：【】6、【單選題】Figureshowsaringofradiuswithanarrowgapof()andlinearchargedensity.ThemagnitudeoftheelectricfieldatthecenterOoftheringis（）.本題答案：【】7、【單選題】Anelectricdipolewithdipolemomentisplacednearalargeplanesheetwithasurfacechargedensity.Ifmakesanangleofwiththenormalofthesheet,themagnitudeofthetorqueexertedonthedipoleis().本題答案：【】8、【單選題】ThefourelectricdipolesareintheuniformelectricfieldinFigure.Whichoneisatthestableequilibriumstate?本題答案：【d】9、【單選題】Bycomparisonwiththeforceofgravity,theelectricalattractionbetweenanelectronandaproton本題答案：【isverymuchstonger.】10、【單選題】Twolightweightmetalspheresaresuspendedneareachotherfrominsulatingthreads.Onespherehasanetcharge;theotherspherehasnonetcharge.Thesphereswill本題答案：【attracteachother.】11、【填空題】Anelectricdipoleisplacedinauniformelectricfieldwithperpendicularto.Theworkdonebytheelectricfieldtotheelectricdipoleintheprocessthatrotatesfromtheorientationinthefiguretothedirectionofis_____.本題答案：【pE##%_YZPRLFH_%##Ep##%_YZPRLFH_%##p*E##%_YZPRLFH_%##E*p】12、【填空題】Inauniformelectricfield,anelectricdipolewithdipolemomentpointsinthedirectionoffield.Thetorqueonthedipoleis.本題答案：【0##%_YZPRLFH_%##zero】13、【填空題】Anelectricdipolewithdipolemomentisinauniformelectricfield.Whenthedipoleisintheunstableequilibriumstate,theanglebetweenandisindegree.本題答案：【180##%_YZPRLFH_%##180.##%_YZPRLFH_%##180.0】Pre-coursepreparation:conceptualunderstanding1、【判斷題】GaussiansurfaceusedinGauss'slawisarealclosedsurfacewhichexistsinanelectricfield.本題答案：【錯誤】2、【判斷題】Theelectricfluxisascalaranditmustbepositive.本題答案：【錯誤】3、【判斷題】Gauss'slawprovidesarelationshipbetweentheelectricfieldonaclosedsurfaceandthechargedistributionwithinthatsurface.本題答案：【正確】UnitTest71、【單選題】Aconductingspherewithradiusandchargeisplacednearaverylargenonconductingplanesheetwithsurfacechargedensity.Undertheconditionofelectrostaticequilibrium,themagnitudeofelectricfieldatcenterofthesphereproducedbythechargeontheconductingsphereis本題答案：【】2、【單選題】FourpointchargesQ1,Q2,Q3,Q4areinspace.Sisaclosedsurface.EisthemagnitudeoftheelectricfieldatanarbitrarypointonsurfaceSanddenotestheelectricfluxthroughS.IfthechargeQ1ismovedfrompointatopointbalongthedashedline,whichofthefollowingstatementsistrue?本題答案：【EchangesbutFEdoesnotchange.】3、【單選題】Shownaretheelectricfieldlinesfortwopointchargeswithasmalldistancebapart.Theratioq1/q2equals本題答案：【-1/3】4、【單選題】InwhichofthefollowingcontextscanGauss’slawbeappliedtofindtheelectricfieldeasily?本題答案：【Apointverynearthesurfaceofalargeuniformlychargedplanesheet.】5、【單選題】ThreepointchargesQ1,Q2,Q3areinspace.Sisaclosedsurface.Q1isoutsideSwhileQ2andQ3areinside.EisthemagnitudeoftheelectricfieldatanarbitrarypointonsurfaceSanddenotestheelectricfluxthroughS.Whichofthefollowingstatementsiscorrect?本題答案：【EdependsonQ1,Q2,Q3whileFEdependsonQ2,Q3.】6、【單選題】AsshowninFigure,thefieldlinesdescribetheelectricfieldcausedbyachargedconductorinair.Throughcalculation,itisfoundthattheelectricfluxpassingthroughaclosedsurfaceAis.Thechargeontheconductoris().本題答案：【】7、【單選題】TheSIunitofelectricfluxis本題答案：【】8、【單選題】Apositivepointcharge+Qislocatedonthex-axisatx=a,andasecondnegativepointcharge-3Qislocatedonthex-axisatx=1.5a.AGaussiansurfacewithradiusr=2aiscenteredattheorigin.ThefluxthroughthisGaussiansurfaceis本題答案：【lessthanzero.】9、【判斷題】Inacertainregionofspace,theelectricfieldisuniform.ItcanbeprovedthatthevolumechargedensityinthisregionmustbezerobasedontheGauss'slaw.本題答案：【正確】10、【判斷題】Ifelectricfluxpassingthroughaclosedsurfaceiszero,tnechargedentsityeverywhereinsidetheclosedsurfacemustbezero.本題答案：【錯誤】11、【填空題】AcubehassidesoflengthL.ApointchargeQislocatedatthecenterofthecube.Theelectricfluxthroughoneofthesixfacesofthecubeis.(informoffraction：/)本題答案：【1/6】12、【填空題】ApointchargeqisplacedsomewherewithadistanceafromthecenterofasolidconductingsphereofradiusR,withaR.Thesphereiselectricallyneutral.Themagnitudeoftheelectricfieldatthespherecenteris______.本題答案：【0】13、【填空題】AsphericalsurfacewithradiusrisinaregionofuniformelectricfieldE.Theelectricfluxthroughthesurfaceis______.本題答案：【0】14、【填空題】Apointchargeqisplacedinsideacavitywithinaconductor.Theconductoriselectricallyneutralandisisolated.Thetotalchargeontheoutersurfaceoftheconductormustbe______.本題答案：【q】15、【填空題】AsshowninFigure,therearethreepointchargesinthespace,,,and.Sisaclosedsurface.Thepermittivityofvacuumis.TheelectricfluxthroughthesurfaceSis本題答案：【-1000000##%_YZPRLFH_%##-10^6##%_YZPRLFH_%##-1*10^6】Pre-coursepreparation:conceptualunderstanding1、【判斷題】Electricpotentialenergyisakindofenergy.Soconsiderasystemofanelectricfieldandapointchargeinit,thesignofthepotentialenergyofthissystemisalwayspositive.本題答案：【錯誤】2、【判斷題】Electronvolt(eV)isaunitofenergyandworklikeJoule.1eV=J.本題答案：【正確】3、【判斷題】BothelectricfieldEandelectricpotentialVcandescribethecharacteristicsofafield.Iftheelectricpotentialatacertainpointiszero,theelectricfieldatthatpointhastobezero.本題答案：【錯誤】UnitTest81、【單選題】AconductingsphereAwithnegativecharge-QisconcentricwithanunchargedconductingsphericalshellB.EandVarethemagnitudesoftheelectricfieldandtheelectricpotentialatpointPinsidetheshell,respectively.Ifthepotentialisassumedtobezeroatinfinity,then本題答案：【E=0,V0.】2、【單選題】Apointcharge+Qisheldstationaryattheorigin.Asecondpointcharge-qmovesfromthepointr=atothepointr=2a.Howmuchworkisdonebytheelectricforceon-q?本題答案：【】3、【單選題】MovingapointchargeqalongtheaxisofachargedringwithradiusRandchargeQ.IfqismovedfromthecenterofringtopointPatadistancexfromthecenter,thentheworkdonebyelectricfieldforceonqequals().(Takepotentialtobezeroatinfinity.)本題答案：【】4、【單選題】Athininsulatingrodisbentintoasemicirculararcofradiusa,andatotalelectricchargeqisdistributeduniformlyalongtherod.Thepotentialatthecenterofcurvatureofthearcequals().(Thepotentialisassumedtobezeroatinfinity.)本題答案：【】5、【單選題】Aconductingspherewithnochargeisplacedbesideaverylargenonconductingplanesheetwithsurfacechargedensity.Undertheconditionofelectrostaticequilibrium,thepotentialatpointPonthesurfaceisV0asshownintheFigure.WhatarethemagnitudeofthefieldandthepotentialatthecenterO?本題答案：【E=0.V=V0.】6、【單選題】Aninfinitelineofchargehaslinearchargedensity.PointsAandBareatdistancesaandbfromtheline.IfapointchargetravelsslowlyfrompointAtopointB,thentheworkdonebytheexternalforceonitis.本題答案：【】7、【單選題】TheelectricpotentialVinacertainregionofspaceisgivenbyinSI.Theelectricfieldinvectorformatpoint(x,y,z)=(1,2,3)is()inSI.本題答案：【】8、【單選題】Inthecaseofachargedconductor,whatisthecharacteroftheconductor?本題答案：【Theelectricfieldmustbezeroeverywhereinsidetheconductor.】9、【單選題】Whichofthefollowinganglesbetweenanelectricdipolemomentandanappliedelectricfieldwillresultinthemoststablestate?本題答案：【0】10、【單選題】AsolidconductingsphereofradiusRiscenteredabouttheoriginofanxyz-coordinatesystem.AtotalchargeQisdistributeduniformlyonthesurfaceofthesphere.Assuming,asusual,thattheelectricpotentialiszeroataninfinitedistance,whatistheelectricpotentialatthecenteroftheconductingsphere?本題答案：【】11、【多選題】Eachofthefollowingpairsofchargesareseparatedbyadistanced.Whichpairhasthehighestpotentialenergy?本題答案：【+3Cand+5C#-3Cand-5C】12、【填空題】TheelectricpotentialVinaregionofspaceisgivenbyinSI,whereAisaconstant.Thex-componentofelectricfieldatpoint(x,y,z)=(2,0,2)is.本題答案：【-4A】13、【填空題】Figureshowsthreeequipotentialsurfacesinspace.AprotontravelsfrompointAtopointBalongthepathrepresentedbythesolidline.Theworkdonebytheelectricfieldontheprotonis______eV.本題答案：【40】Pre-coursepreparation:conceptualunderstanding1、【判斷題】Twoobjectsseparatedbyaninsulatorhavetobechargedtoformacapacitor.本題答案：【錯誤】2、【判斷題】Adielectricisanonconductingmaterial.本題答案：【正確】3、【判斷題】Whenadielectricmaterialisputinanelectricfield,theinducedsurfacechargesariseasaresultofredistributionofpositiveandnegativechargewithinthedielectricmaterial,thephenomenoniscalledpolarization.本題答案：【正確】UnitTest91、【單選題】ThepotentialdifferenceVofaparallel-platecapacitorwithareaAandseparationdmaintainsunchanged.ThespacebetweentheplatesisfullyfilledwithadielectricofdielectricconstantKandresistivity.The“l(fā)eakage”currentcarriedbythedielectricisgivenby().本題答案：【】2、【單選題】Aparallel-platecapacitorhaschargeQand-Qonitsplates.Onehalfofthegapbetweenthetwoplatesisfilledwithuniformdielectricwithpermittivityandtheotherhalfisfilledwithairasshowninthefigure.WhatistherelationbetweentheelectricfieldE0intheairandEinthedielectric?本題答案：【E0E.】3、【單選題】Aparallel-platecapacitorhaschargeQand-Qonitsplates.Onehalfofthegapbetweenthetwoplatesisfilledwithuniformdielectricwithpermittivityandtheotherhalfisfilledwithairasshowninthefigure.WhatistherelationbetweentheelectricfieldE0intheairandEinthedielectric?本題答案：【E0=E.】4、【單選題】Whichoneiscorrectaboutthecapacitanceofaparallel-platecapacitor?本題答案：【Itdependsontheplateseparation.】5、【單選題】AparallelplatecapacitorwithdielectrichasplatesofareaAandspacingofd.ThedielectrichasdielectricconstantKanddielectricstren