在线网课知道智慧《大学物理（下）（College Physics II）(重庆大学)》单元测试考核答案

第一章单元测试1【单选题】(2分)Acharge+Qisfixedinpositionasasmallcharge+qisbroughtnearitandreleasedfromrest.Whichbestdescribesthemagnitudeofthevelocityofthecharge+qasr,thedistancebetweenthechargesincreases?()A.Themagnitudeofthevelocitywillremainconstant.B.Themagnitudeofthevelocitywilldecrease,anditsrateofdecreasewillalsodecrease.C.Themagnitudeofthevelocitywillincrease,anditsrateofincreasewillalsoincrease.D.Themagnitudeofthevelocitywillincrease,butitsrateofincreasewilldecrease.E.Themagnitudeofvelocitywillincrease,butitsrateofdecreasewillincrease.2【单选题】(2分)Themotionoflargebodiesatgreatdistancesisgovernedprimarilybygravityandnotbytheelectrostaticforcebecause()A.gravityisamuchstrongerforcethantheelectrostaticforceB.themajorityofmatteriselectricallyneutralC.oftherelativescarcityofantiparticlesD.theelectrostaticforceisfeltonlyovershortdistancesE.theelectrostaticforceiscanceledoutbythemagneticforce3【单选题】(2分)Anobjectwithachargeof–2qfeelsaforceofFwhenputatapointPinanelectricfield.IntermsofFandq,thestrengthoftheelectricfieldatthispointis().C.4【单选题】(2分)正确答案：EAllofthefollowingaretrueaboutGauss'lawEXCEPT()A.Gauss'lawstatesthatthefluxthroughtheclosedsurfaceisproportionaltothetotalchargewithinthesurface.B.Gauss'lawisusefulwhentheelectricfieldiszero.C.Gauss'lawreferstothefluxthroughaclosedsurface.D.Gauss'lawisusefulwhentheelectricfieldisperpendiculartothedifferentialarea.E.ArectangleisanexampleofaGaussiansurface.5【单选题】(2分)BasedonGauss'Law,whichofthefollowingaffectstheelectricfluxthroughaGaussiansurface?()A.amagneticdipoleoutsideofthesurfaceB.astationaryelectricchargeoutsidethesurfaceC.astationaryelectricchargeenclosedbythesurfaceD.amagneticmonopoleenclosedbythesurfaceE.achargemovingwithaconstantvelocityoutsidethesurface6【单选题】(2分)正确答案：EWhichofthefollowingpairsofchargedistributionsandGaussiansurfacesarecorrectlypairedsuchthattheGaussiansurfacecanbeusedtofindtheelectricfieldassociatedwiththatchargedistribution?()A.planeandsphereB.infinitelineandsphereC.planeandrectangleD.infinitelineandrectangleE.planeandcylinder7【单选题】(2分)IftheelectricfielddoespositiveworkonanegativechargeasthechargeundergoesadisplacementfrompointAtopointBwithinanelectricfield,thentheelectricalpotentialenergy()A.decreases.B.electricfieldscannotdowork.C.ispositive.D.isnegative.E.increases.8【单选题】(2分)Thenegativederivativeofelectricpotentialwithrespecttoradiusisequalto（）A.chargeB.electricfieldC.electricforceD.capacitanceE.potentialenergy9【单选题】(2分)Thepotentialdifferenceduetoafiniterodalongthex-axisisgivenbytheequationV(x)=C[ln(x+L)–ln(x)],whereCandLareconstants.Whatistheelectricfieldduetothisrod?（）A.10【单选题】(2分)PointAisadistanceLtotheleftofachargeQ.PointBisadistance3LtotheleftofpointA.IftheelectricfieldatpointAduetochargeQisE,whatistheelectricfieldatpointB?A.EB.E/3C.3ED.E/16E.E/911【单选题】(2分)A.12【单选题】(2分)Twosolidspheres,bothofradius5cm,carryidenticaltotalchargesof2nC.SphereAisagoodconductor.SphereBisaninsulator,anditschargeisdistributeduniformlythroughoutitsvolume.Howdothemagnitudesoftheelectricfieldstheyseparatelycreateataradialdistanceof6cmcompare?B.13【单选题】(2分)D.14【单选题】(2分)C.第二章单元测试1【单选题】(2分)Twochargedconductingspheresaretouchedtogether.Chargeflowsbetweenthemuntilwhichofthefollowingisthesameforbothspheres?()A.electricfieldatthesurfaceB.electricpotentialC.totalchargeD.totalenergyE.electricfieldatthecenter2【单选题】(2分)正确答案：EAnunchargedmetalsphereisplacedwithinauniformelectricfield.Whichofthefollowingistrueaboutthenetforceandtorqueonthesphere?（）A.Thenetforceiszeroandthenettorqueisagainstthedirectionofthefield.B.Thenetforceisagainstthedirectionofthefield,andthenettorqueisagainstthedirectionofthefield.C.Thenetforceisinthedirectionofthefield,andthenettorqueisinthedirectionofthefield.D.Thenetforceiszeroandthenettorqueisinthedirectionofthefield.E.Thenetforceandnettorquearebothzero.3【单选题】(2分)Asolidsphereconsistsofametalcore,anon-conductingmiddleshell,andametaloutershell.Ifapositivechargeisplacedonthecore,whereinthespherewillanetpositivechargebefound?()A.ontheoutersurfaceofthecoreB.ontheoutersurfaceoftheoutershellC.onboththeoutersurfaceofthecoreandtheoutersurfaceoftheoutershellD.evenlydistributedthroughoutthecoreE.evenlydistributedthroughoutthetwometalregions4【单选题】(2分)Twoconductingspheresofdifferentradiieachcarryacharge+Q.Whichofthefollowingoccurswhenthetwospheresaretouchedtogether?()A.Positivechargeflowsfromthesmallerspheretothelargersphereuntiltheelectricpotentialatthesurfaceofeachsphereisthesame.B.Positivechargeflowsfromthelargerspheretothesmallersphereuntiltheelectricpotentialatthesurfaceofeachsphereisthesame.C.Positivechargeflowsfromthesmallerspheretothelargersphereuntiltheelectricfieldatthesurfaceofeachsphereisthesame.D.Nochargeflows.E.Positivechargeflowsfromthelargerspheretothesmallersphereuntiltheelectricfieldatthesurfaceofeachsphereisthesame.5【单选题】(2分)Threeidenticalmetalspheresaremountedoninsulatingstands.Initially,sphereAhasanetchargeofqandspheresBandCareuncharged.SphereAistouchedtosphereBandremoved.ThensphereAistouchedtosphereCandremoved.WhatisthefinalchargeonsphereA?()A.qB.q/2C.q/3D.q/4E.q/66【单选题】(2分)Aparallel-platecapacitorhascapacitanceC.Asecondparallel-platecapacitorhasplateswithtwicetheareaandhalftheseparation.Thecapacitanceofthissecondcapacitorismostnearly（）A.2CB.C/4C.4CD.CE.C/27【单选题】(2分)AllofthefollowingaretrueaboutsphericalcapacitorsEXCEPT()A.ThecapacitanceisequaltothechargedividedbythepotentialdifferenceB.TheelectricfieldpointsradiallytowardsthecenterofthespheresC.TheelectricfieldbetweenthetwospheresisdeterminedonlybythechargeontheoutersphereD.TheelectricfieldoutsidetheoutersphereiszeroE.Thepotentialdifferencebetweenthetwospheresisthenegativeintegraloftheelectricfield8【单选题】(2分)Abatteryisattachedtoseveraldifferentcapacitorsconnectedinparallel.Whichofthefollowingstatementsistrue?（）A.Thepotentialdifferenceacrosseachcapacitoristhesame,andtheequivalentcapacitanceisgreaterthananyofthecapacitorsinthegroup.B.Thepotentialdifferencesacrossthecapacitorsarethesameonlyifthecapacitancesarethesame.C.Allcapacitorshavethesamecharge,andtheequivalentcapacitanceisgreaterthanthecapacitanceofanyofthecapacitorsinthegroup.D.Thecapacitorwiththesmallestcapacitancecarriesthelargestcharge.E.Thecapacitorwiththelargestcapacitancecarriesthesmallestcharge.9【单选题】(2分)Aparallel-platecapacitorisconnectedtoabattery.Whathappenstothestoredenergyiftheplateseparationisdoubledwhilethecapacitorremainsconnectedtothebattery?（）A.Itisdoubled.B.Itdecreasesbyafactorof2.C.Itincreasesbyafactorof4.第三章D.Itdecreasesbyafactorof4.E.Itremainsthesame.10【单选题】(2分)A.9JB.18JC.0.06JD.0.0036JE.0.03J第三章单元测试1【单选题】(2分)正确答案：EAparticlewithelectricchargeisfiredintoaregionofspacewheretheelectricfieldiszero.Itmovesinastraightline.Canyouconcludethatthemagneticfieldinthatregioniszero?()A.No;thefieldmightbeperpendiculartotheparticle’svelocity.B.No;theparticlemightneedtohavechargeoftheoppositesigntohaveaforceexertedonit.C.Yes,youcan.D.No;anobservationofanobjectwithelectricchargegivesnoinformationaboutamagneticfield.E.No;thefieldmightbeparalleltotheparticle’svelocity.2【单选题】(2分)Whichofthefollowingexplainswhyamagneticfielddoesnoworkonamovingchargedparticle?()A.Themagneticforcedependsonthespeedoftheparticle.B.Themagneticforceisalwaysperpendiculartothedirectionofmotion.C.Themagneticforceisconservative.D.Thereisalwaysanelectricfieldthatcancelstheworkdonebythemagneticfield.E.Themagneticforcedependsonthedirectionofmotionoftheparticle.3【单选题】(2分)正确答案：ETwolongparallelwiresarefixedatadistancedapartandeachcarryacurrentofI.TheforceofattractionbetweenthemisF.Ifthedistancebetweenthewiresisdoubledandthecurrentineachofthewiresisdoubled,whatisthenewforceofattractionbetweenthewires?()A.4FB.FC.F/4D.F/2E.2F4【单选题】(2分)正确答案：ETheBiot-SavartLawisusedto（）A.determinetheelectricfieldcreatedbyanelectriccurrentB.determinetheforcefieldcreatedbyanelectriccurrentC.determinethemagneticfieldcreatedbyindividualpointchargesD.determinetheelectricfieldcreatedbyindividualpointchargesE.determinethemagneticfieldcreatedbyanelectriccurrent5【单选题】(2分)Iftwocurrentcarryingwiresexertaforceof50Noneachother,whatforcewilltheyfeelifthedistancebetweenthemishalved?()A.200NB.100NC.25ND.50NE.12.5N6【单选题】(2分)正确答案：EWhichofthefollowingisnotusedwhenapplyingAmpere'slaw?()A.magneticfieldB.alengthdifferentialC.alineintegralD.adotproductE.asurfaceintegral7【单选题】(2分)Aninfinitelylargecurrent-carryingsheetliesonthexy-planecarryingcurrentinthey-direction.Whichofthefollowingisfalseaboutthemagneticfieldthatitcreates?()A.Themagneticfielddependsonthecurrentdensityinthesheet.B.Themagneticfieldisinthepositivex-direction.C.ThemagneticfieldcanbecalculatedusingAmpere’slaw.D.Themagneticfielddependsonthedistanceawayfromtheplane.8【单选题】(2分)正确答案：EE.9【单选题】(2分)D.0.002V10【单选题】(2分)Thereisaclockwisecurrentinacircularloopofwireinanexternalmagneticfielddirectedoutofthepageasshowninthediagram.TheeffectofthemagneticfieldistomaketheloopA.contract.B.rotateintheplaneofthepage.C.expand.D.moveintothepageE.rotateperpendicularlytothepage.11【单选题】(2分)WhatisthemagneticfieldatpointPduetothesegmentofwireABcarryingcurrentI?C.12【单选题】(2分)正确答案：EA.(BI–l/2)+B.mg–IB/2C.mg+IBlD.g+lBE.mg–IBl第四章单元测试1【单选题】(2分)Themagneticfieldfromaloopofcurrentcarryingwireintheplaneofthepageisdirectedoutofthepage.Inwhichdirectiondotheelectronsinthewireloopmove?()A.theyarestationaryB.clockwiseC.theyallmovetotheleftsideoftheloopD.theyallmovetotherightsideoftheloopE.counterclockwise2【单选题】(2分)正确答案：EAmagneticfieldthatisincreasingwithtimeisdirectedoutofthepageandpassesthroughacircularloopofwireintheplaneofthepage.Whichofthefollowingistrue?()A.Theloopwillrotateaboutanaxisperpendiculartotheplaneofthepage.B.NochangewilloccurintheloopC.Theloopwillrotateaboutadiameter.D.Thereisaninducedcurrentintheloopthatiscounterclockwiseindirection.E.Thereisaninducedcurrentintheloopthatisclockwiseindirection.3【单选题】(2分)正确答案：ELenz'sLawindicateswhichofthefollowing?()A.Therearenomagneticmonopoles.B.TheinducedEMFisequaltothechangeinmagneticflux.C.Lightincidentonaconcavemirrorproducesavirtualimage.D.E.TheinducedEMFproducesamagneticfieldthatopposesthechangethatproducedtheEMF.Theforceexertedbyamagneticfieldisperpendiculartoboththemotionofthechargedparticleandthedirectionofthemagneticfield.4【单选题】(2分)IfthemagneticfieldBthroughaloopofwireisdecreasing,theinducedmagneticfieldwillbe()A.thereisnoinducedmagneticfieldB.perpendiculartoBC.intheoppositedirectionofBD.inthesamedirectionasBE.atanacuteangletoB5【单选题】(2分)Along,finewireiswoundintoacoilwithinductance5mH.Thecoilisconnectedacrosstheterminalsofabattery,andthecurrentismeasuredafewsecondsaftertheconnectionismade.ThewireisunwoundandwoundagainintoadifferentcoilwithL=10mH.Thissecondcoilisconnectedacrossthesamebattery,andthecurrentismeasuredinthesameway.Comparedwiththecurrentinthefirstcoil,isthecurrentinthesecondcoil()A.fourtimesaslargeB.twiceaslargeC.unchangedD.halfaslargeE.one-fourthaslarge6【单选题】(2分)Whichofthefollowingcircuitelementstoresenergyintheelectromagneticfield?()A.VariableresistorB.ResistanceC.CondenserD.Inductor7【单选题】(2分)正确答案：EAstraightrodoflength3.0misheldperpendiculartoamagneticfieldof2.0T.Itisrotatedaboutitsmidpointatarateof5.0revolutionspersecond,remainingperpendiculartothefieldtheentiretime.Theemfgeneratedintherodismostnearly()A.70.7VB.22.5VC.94.2VD.45VE.141V8【单选题】(2分)Acircularloopofwirewitharadiusof5cmrotatesclockwiseataconstantangularvelocitythroughamagneticfieldB=5T.Theplaneoftheloopgoesfrombeingperpendiculartothefieldtobeingata45ºanglewiththefieldin0.25s.TheaverageemfinducedintheloopwillbeA.0.092VB.0.046VC.0VD.0.023VE.0.012V9【单选题】(2分)ThediagramshowsawireloopinauniformmagneticfieldBthatpointsoutofthepage.Inwhichwayshouldtheloopbemovedtoinduceacurrentwithintheloop?A.CurrentcannotbeinducedintheloopbecausethemagneticfieldisuniformB.Alongthey-axiswithconstantvelocityC.Alongthex-axiswithincreasingvelocityD.Alongthez-axiswithconstantvelocityE.Rotatetheloopaboutthez-axis10【单选题】(2分)正确答案：EInthediagrambelow,asegmentofwire,RS,whichis0.20minlength,isfreetoslidealongaU-shapedwirelocatedinauniform0.60-Tmagneticfielddirectedintothepage.IfwiresegmentRSisslidtotherightataconstantspeedof4.0meterspersecond,thepotentialdifferenceinducedacrosstheendsofthewiresegmentisA.4.8VB.1.2VC.2.4VD.0.12VE.0.48V第五章单元测试1【单选题】(2分)Thepositionofa0.64-kgmassundergoingsimpleharmonicmotionisgivenbyx=(0.160m)cos(πt/16).Whatisitspositionatt=5.0s?()A.0.159mB.0.160mC.0.076mD.0.089mE.0.113m2【单选题】(2分)Ifanobjectofmassmattachedtoalightspringisreplacedbyoneofmass9m,thefrequencyofvibratingsystemchangesbywhatmultiplicationfactor?()A.6.0B.1/3C.1/9D.9.0E.3.03【单选题】(2分)Whichofthefollowingstatementsaboutaspring-blockoscillatorinsimpleharmonicmotionaboutitsequilibriumpointisfalse?()A.Thedisplacementisdirectlyrelatedtotheacceleration.B.Theaccelerationvectorisalwaystowardtheequilibriumpoint.C.Theaccelerationandvelocityvectorsalwayspointinthesamedirection.D.Theaccelerationanddisplacementvectorsalwayspointinoppositedirections.4【单选题】(2分)正确答案：EAnobject-springsystemmovingwithsimpleharmonicmotionhasanamplitudeA.whenitskineticenergyequalstwicethepotentialenergystoredinthespring,whatisthepositionxoftheobject?()A.AB.0C.someotherD.A/3E.A/√35【单选题】(2分)正确答案：ESupposea0.3-kgmassonaspringthathasbeencompressed0.10mhaselasticpotentialenergyof1.0J.Howmuchfurthermustthespringbecompressedtotripletheelasticpotentialenergy?()A.0.17mB.0.30mC.0.05mD.0.20mE.0.07m6【单选题】(2分)Triplingthemassofthebobonasimplependulumwillcauseachangeinthefrequencyofthependulumswingbywhatfactor?()A.3.0B.9.0C.0.33D.1.0E.127【单选题】(2分)Youstandontheendofadivingboardandbouncetosetitintooscillation.Youfindamaximumresponseintermsoftheamplitudeofoscillationoftheendtheboardwhenyoubounceatfrequencyf.Younowmovetothemiddleoftheboardandrepeattheexperiment.Theresonancefrequencyforforcedoscillationsatthispointwill()A.decreaseB.beunabletodetermineC.bethesameasfD.increase8【单选题】(2分)Foramasssuspendedonaspringintheverticaldirection,thetimeforonecompleteoscillationwilldependon:A.thetimedoesn'tdependontheB.themaximumspeedoftheoscillatingmass.C.theD.boththeE.thedistancethemasswasoriginallypulleddown.9【单选题】(2分)正确答案：EAmassonaspringvibratesinsimpleharmonicmotionatafrequencyof4.0Hzandanamplitudeof4.0cm.Ifatimerisstartedwhenitsdisplacementisamaximum(hencex=4cmwhent=0),whatistheaccelerationmagnitudewhent=3s?E.第六章单元测试1【单选题】(2分)Atransversewavetravelsalongthex-axis.Theparticlesofthemediummustmove()A.Alongthey-axisB.Alongthex-axisC.Inthey-zplaneD.Alongthez-axis2【单选题】(2分)Whichofthefollowingarelongitudinalwaves?()A.SurfacewaterwavesonthelakeB.RadiowavessentoutfromthebroadcastingstationC.SoundwavesproducedbythevibratingstringoftheguitarD.Lightraysfromthesun3【单选题】(2分)Whichofthefollowingcharacteristicofawaveisindependentoftheothers?()A.wavelengthB.speedC.frequencyD.amplitude4【单选题】(2分)Assumeachangeatthesourceofsoundreducesthewavelengthofasoundwaveinairbyafactorof2.Whathappenstoitsfrequency?()A.Itincreasesbyafactorof2.B.Itincreasesbyafactorof4.C.Itisunchanged.D.Itdecreasesbyafactorof25【单选题】(2分)Whichofthefollowingfunctionsrepresentatravelingwave?()A.y=pcos(rt−qx)B.noneofotherchoicesC.y=pcos(qx)sin(rt)D.y=1/(rt−qx)6【单选题】(2分)Asourcevibratingatconstantfrequencygeneratesasinusoidalwaveonastringunderconstanttension.Ifthepowerdeliveredtothestringisdoubled,bywhatfactordoestheamplitudechange?()A.2B.cannotbepredicted.C.√2D.0.707E.47【单选题】(2分)Astandingwaveissetupina200-cmstringfixedatbothends.Thestringvibratesin5distinctsegmentswhendrivenbya120-Hzsource.Whatisthewavelengthofthestandingwave?()A.40cmB.10cmC.20cmD.80cmE.100cm8【单选题】(2分)C.第七章单元测试1【单选题】(2分)Whenlightpassesfromamaterialwithahighindexofrefractionintomaterialwithalowindexofrefraction:()A.somelightisreflectedwitha180°changeofphase.B.noneofthelightisreflected.C.thelightthatisnotreflectedhasa180°changeofphase.D.somelightisreflectedwithoutachangeofphase.2【单选题】(2分)Twolightsourcesaresaidtobecoherentifthey()A.areofthesamefrequency,andmaintainaconstantphasedifference.B.areofthesamefrequency.C.areofthesameamplitude,andmaintainaconstantphasedifference.D.areofthesamefrequencyandamplitude.3【单选题】(2分)Coherentlightofasinglefrequencypassesthroughadoubleslitwithaseparationd,toproduceapatternonascreenasdistanceDfromtheslits.Whatwouldcausetheseparationbetweenadjacentminimaonthescreentoincrease?()A.increasethefrequencyoftheincidentlightB.increasetheindexofrefractionofthemediuminwhichthesetupisimmersedC.increasetheseparationdbetweentheslitsD.increasethedistance4【单选题】(2分)Aplanemonochromaticlightwaveisincidentonadoubleslitsystem.Astheviewingscreenismovedawayfromthedoubleslit,whathappenstotheseparationbetweentheinterferencefringesonthescreen?()A.Itmayincreaseordecrease,dependingonthewavelengthofthelight.B.Itdecreases.C.Moreinformationisrequired.D.Itincreases.E.Itremainsthesame.5【单选题】(2分)Greenlighthasawavelengthof500nminair.Thegreenlightisreflectedperpendicularlyfromathinfilmofaplasticwithanindexofrefraction2.00.Thefilmappearsbrightinthereflectedlight.Howmuchadditionalthicknesswouldmakethefilmappeardark?()A.500nmB.125nmC.250nmD.62.5nmE.1,000nm6【单选题】(2分)Interferencepatternisobservedinwedge-shapedfilmandfringewidthisnoted.Nowtheangleofwedgeisreduced.Whatwillbetheeffectonfringewidth?()A.FringewidthwilldisappearB.TherewillnotanyeffectC.FringewidthincreasesD.Fringewidthdecreases7【单选题】(2分)ThecenterspotofNewton'sringsisdark.Thisdestructiveinterferenceoccursbecause:()A.bothwaveshaveatrough.B.thetwobeamstraveldistancesthataredifferentbyhalfawavelength.C.bothwaveschangephaseby180°astheyarereflected.D.onebeamchangesphaseby180°whenitisreflected.8【单选题】(2分)A.500nmB.404nmC.212nmD.285nmE.313nm9【单选题】(2分)A.Thedarkcirclechangesintoabrightcircle,thenintoadarkcircle,andthenintoabrightcircle.B.Thedarkcirclechangesintoabrightcircle.C.Thedarkcirclechangesintoabrightcircleandthenbackintoadarkcircle.D.Thereisnochangeinthepattern.10【单选题】(2分)Newtonsringsexperimentisperformedandradius(ordiameter)iscalculated.NowPlano-convexlensisreplacedwithanotherPlano-convexlensofgreaterRadiusofcurvature.Whatwillbeeffectonradius(ordiameter)?A.Radius(ordiameter)willremainconstantbuttherewillbemorebrightnessB.Radius(ordiameter)willincreaseC.TherewillbenoeffectD.Radius(ordiameter)willdecrease11【单选题】(2分)Inthinfilmofwedgeshaped,bykeepingallotherparametersconstant,ifonlywavelengthofincidentlightisincreased.Whatwillbetheeffectonbandwidth?A.TherewillnotanyeffectB.BandwidthincreasesC.BandwidthdecreasesD.Bandswillmerge第八章单元测试1【单选题】(