大學物理（下）（CollegePhysicsII）知到智慧樹期末考試答案題庫2025年重慶大學Youstandontheendofadivingboardandbouncetosetitintooscillation.Youfindamaximumresponseintermsoftheamplitudeofoscillationoftheendtheboardwhenyoubounceatfrequencyf.Younowmovetothemiddleoftheboardandrepeattheexperiment.Theresonancefrequencyforforcedoscillationsatthispointwill()

答案:increaseWhichoneoftheglowingmagneticfieldgivesthelargestmagnitude?()

答案:afieldof1mTWhichofthefollowingwillresultinaninducedEMFinastationarycircularloopofwireinaperpendicularmagneticfield?()

答案:bendingthewireloopintoasquareWhichofthefollowingstatementsinvolvingconductorsisFALSE?（）

答案:Theelectricpotentialinsideiszero.Whichofthefollowingstatementsaboutaspring-blockoscillatorinsimpleharmonicmotionaboutitsequilibriumpointisfalse?()

答案:Theaccelerationandvelocityvectorsalwayspointinthesamedirection.WhichofthefollowingpairsofchargedistributionsandGaussiansurfacesarecorrectlypairedsuchthattheGaussiansurfacecanbeusedtofindtheelectricfieldassociatedwiththatchargedistribution?()

答案:planeandcylinderWhichofthefollowingisnotusedwhenapplyingAmpere'slaw?()

答案:asurfaceintegralWhichofthefollowinginconservedwhenlightwavesinterfere?()

答案:EnergyWhichofthefollowingfunctionsrepresentatravelingwave?()

答案:y=1/(rt?qx)Whichofthefollowingexplainswhyamagneticfielddoesnoworkonamovingchargedparticle?()

答案:Themagneticforceisalwaysperpendiculartothedirectionofmotion.Whichofthefollowingdevicescanbeusedtoproducebothatransverseandlongitudinalwaves?()

答案:AhelicalspringWhichofthefollowingcircuitelementstoresenergyintheelectromagneticfield?()

答案:InductorWhichofthefollowingcharacteristicofawaveisindependentoftheothers?()

答案:amplitudeWhichofthefollowingarelongitudinalwaves?()

答案:SoundwavesproducedbythevibratingstringoftheguitarWhenviewedinwhitelight,asoapbubbleshowscolorsbecauseof()

答案:InterferenceWhenlightpassesfromamaterialwithahighindexofrefractionintomaterialwithalowindexofrefraction:()

答案:somelightisreflectedwithoutachangeofphase.Whatprincipleisresponsibleforlightspreadingasitpassesthroughanarrowslit?()

答案:diffractionWhatistheratioofpotentialduetoasphericalshellofradiusRandasolidconductingsphereofradiusR,forr＜R?（）

答案:1:1WhatisthepotentialduetoasphericalshellofchargeQandradiusRforr＜R?（）

答案:WhatisthepotentialduetoasphericalshellofchargeQandradiusRforr＜R?（）WhatisthemagneticfieldduetoawireofinfinitelengthcarryingacurrentI,adistanceaawayfromthewire?()

答案:WhatisthemagneticfieldduetoawireofinfinitelengthcarryingacurrentI,adistanceaawayfromthewire?()Whatisthehighestorderspectrumwhichmaybeseenwithmonochromaticlightofwavelength500nmbymeansofdiffractiongratingwith5000lines/cm?()

答案:3WhatistheelectricpotentialinsideahollowsphereofradiusRthatholdsachargeQ?()

答案:WhatistheelectricpotentialinsideahollowsphereofradiusRthatholdsachargeQ?()Whathappenstotheamplitudeoftheinducedemfwhentherateofrotationofageneratorcoilisdoubled?()

答案:Itbecomestwotimeslarger.Whatcreatesamagneticfield?Morethanoneanswermaybecorrect.()

答案:astationaryconductorcarryingelectriccurrentWhatcausesthebrightlycoloredpatternssometimesseenonwetstreetscoveredwithalayerofoil?Choosethebestanswer.()

答案:reflectionandinterferenceTwosolidspheres,bothofradius5cm,carryidenticaltotalchargesof2nC.SphereAisagoodconductor.SphereBisaninsulator,anditschargeisdistributeduniformlythroughoutitsvolume.Howdothemagnitudesoftheelectricfieldstheyseparatelycreateatradius4cmcompare?

答案:Twosolidspheres,bothofradius5cm,carryidenticaltotalchargesof2nC.SphereAisagoodconductor.SphereBisaninsulator,anditschargeisdistributeduniformlythroughoutitsvolume.Howdothemagnitudesoftheelectricfieldstheyseparatelycreateatradius4cmcompare?Twosolidspheres,bothofradius5cm,carryidenticaltotalchargesof2nC.SphereAisagoodconductor.SphereBisaninsulator,anditschargeisdistributeduniformlythroughoutitsvolume.Howdothemagnitudesoftheelectricfieldstheyseparatelycreateataradialdistanceof6cmcompare?

答案:Twosolidspheres,bothofradius5cm,carryidenticaltotalchargesof2nC.SphereAisagoodconductor.SphereBisaninsulator,anditschargeisdistributeduniformlythroughoutitsvolume.Howdothemagnitudesoftheelectricfieldstheyseparatelycreateataradialdistanceof6cmcompare?Twosolenoids,AandB,arewoundusingequallengthsofthesamekindofwire.Thelengthoftheaxisofeachsolenoidislargecomparedwithitsdiameter.TheaxiallengthofAistwiceaslargeasthatofB,andAhastwiceasmanyturnsasB.WhatistheratiooftheinductanceofsolenoidAtothatofsolenoidB?()

答案:1/2Twopolaroidsareplacedwiththeirtransmissionaxisat90otoeachotherandtransmittedIntensityoflightiszero.Ifonemorepolaroidisplacedbetweenthesetwo,bisectingtheanglebetweenthem,thentheratiooftransmittedintensityoflighttotheintensityofunpolarizedlightwillbe()

答案:1/8Twoparallelconductingplates,separatedbyadistanced,areconnectedtoabatterywithavoltagesourcethatsuppliesapotentialdifferenceV.Iftheseparationbetweentheplatesishalved,whichofthefollowingwilloccur?()

答案:Theelectricchargeontheplateswillbedoubled.Twolongparallelwires,fixedadistancedapartinspace,eachcarryacurrentI.TheforceofattractionbetweenthemisF.WhichotherarrangementofcurrentsinlongparallelwireswouldproducethesameforceF?()

答案:acurrentof3Iandadistanceof9dTwolongparallelwiresarefixedatadistancedapartandeachcarryacurrentofI.TheforceofattractionbetweenthemisF.Ifthedistancebetweenthewiresisdoubledandthecurrentineachofthewiresisdoubled,whatisthenewforceofattractionbetweenthewires?()

答案:2FTwolightsourcesaresaidtobecoherentifthey()

答案:areofthesamefrequency,andmaintainaconstantphasedifference.Twoconductingspheresofdifferentradiieachcarryacharge+Q.Whichofthefollowingoccurswhenthetwospheresaretouchedtogether?()

答案:Positivechargeflowsfromthesmallerspheretothelargersphereuntiltheelectricpotentialatthesurfaceofeachsphereisthesame.Twocoherentsourcesofintensityratio100:1interfere.Theratioofinterferenceatthemaximaandminima()

答案:121:81Twochargedconductingspheresaretouchedtogether.Chargeflowsbetweenthemuntilwhichofthefollowingisthesameforbothspheres?()

答案:electricpotentialTriplingthemassofthebobonasimplependulumwillcauseachangeinthefrequencyofthependulumswingbywhatfactor?()

答案:1.0Tofindprominentdiffraction,thesizeofdiffractionobjectshouldbe()

答案:comparabletoorderofwavelengthoflightThreeidenticalmetalspheresaremountedoninsulatingstands.Initially,sphereAhasanetchargeofqandspheresBandCareuncharged.SphereAistouchedtosphereBandremoved.ThensphereAistouchedtosphereCandremoved.WhatisthefinalchargeonsphereA?()

答案:q/4Thepotentialofapoint-chargeisgivenbytheequationV(r)=kq/r.Determinetheelectricfieldatsomedistancerfromq.（）

答案:Thepotentialofapoint-chargeisgivenbytheequationV(r)=kq/r.Determinetheelectricfieldatsomedistancerfromq.（）Thepotentialdifferenceduetoafiniterodalongthex-axisisgivenbytheequationV(x)=C[ln(x+L)–ln(x)],whereCandLareconstants.Whatistheelectricfieldduetothisrod?（）

答案:Thepotentialdifferenceduetoafiniterodalongthex-axisisgivenbytheequationV(x)=C[ln(x+L)–ln(x)],whereCandLareconstants.Whatistheelectricfieldduetothisrod?（）Thepositionofanobjectmovingwithsimpleharmonicmotionisgivenbyx=4cos(6πt),wherexisinmetersandtisinseconds.Whatistheperiodoftheoscillatingsystem?()

答案:1/3sThepositionofa0.64-kgmassundergoingsimpleharmonicmotionisgivenbyx=(0.160m)cos(πt/16).Whatisitspositionatt=5.0s?()

答案:0.089mThepositionofa0.64-kgmassundergoingsimpleharmonicmotionisgivenbyx=(0.160m)cos(πt/16).Whatisitsperiodofoscillation?()

答案:32sThenegativederivativeofelectricpotentialwithrespecttoradiusisequalto（）

答案:electricfieldThemotionoflargebodiesatgreatdistancesisgovernedprimarilybygravityandnotbytheelectrostaticforcebecause()

答案:themajorityofmatteriselectricallyneutralThemotionofapistoninanautomobileengineisnearlysimpleharmonic.Ifthe1-kgpistontravelsbackandforthoveratotaldistanceof10.0cm,whatisitsmaximumspeedwhentheengineisrunningat3000rpm?()

答案:15.7m/sThemagneticfieldfromaloopofcurrentcarryingwireintheplaneofthepageisdirectedoutofthepage.Inwhichdirectiondotheelectronsinthewireloopmove?()

答案:clockwiseThekineticenergyofthebobonasimplependulumswinginginsimpleharmonicmotionhasitsmaximumvaluewhenthedisplacementfromequilibriumisatwhatpointinitsswing?()

答案:zerodisplacementTheforceactingonlongcurrentcarryingwireinamagneticfieldisaffectedbyallofthefollowingEXCEPT()

答案:thevoltageacrossthewire.Theelectricpotentialadistancerawayfromacylindercanbecalculatedbydividingachargeqinto()

答案:theworkdoneontheelectricfieldasachargeqmovesfromapointonthecylindertoapointoutsidethecylinder.TheelectricfieldneareachofthefollowingchargedobjectscanbedeterminedeasilyusingGauss'LawEXCEPT()

答案:anarcThedistancebetweentwosuccessivepeaksofasinusoidalwavetravelingalongastringis2m.Ifthefrequencyofthewaveis4Hz,whatisthespeedofthewave(inm/s)?()

答案:8Thedisplacementy(x,t)ofaparticulartravellingwavehastheformy(x,t)=Asin(x+πt/2).Whatisthespeedofthiswave,ignoringitsdirection?()

答案:π/2Thecentersoftwocircularloopsareseparatedbyafixeddistance.Forwhatrelativeorientationoftheloopsistheirmutualinductanceamaximum?()

答案:coaxialandlyinginparallelplanesThecenterspotofNewton'sringsisdark.Thisdestructiveinterferenceoccursbecause:()

答案:onebeamchangesphaseby180°whenitisreflected.TheBiot-SavartLawisusedto（）

答案:determinethemagneticfieldcreatedbyanelectriccurrentSupposeYoung’sdouble-slitexperimentisperformedinairusingredlightandthentheapparatusisimmersedinwater.Whathappenstotheinterferencepatternonthescreen?()

答案:Thebrightfringesareclosertogether.Supposea0.3-kgmassonaspringthathasbeencompressed0.10mhaselasticpotentialenergyof1.0J.Howmuchfurthermustthespringbecompressedtotripletheelasticpotentialenergy?()

答案:0.07mSignificantdiffractionofXraycanbeobtained()

答案:ByAtomiccrystalSecondglassplateinMichelsonInterferometerisknownas（）

答案:CompensatingglassplatePlanepolarizedlightissentthroughtwoconsecutivepolarizers,thefirsthavingitsplaneofpolarizationinthesamedirectionastheincidentlightandthesecondhavingitsplaneat90°totheoriginalplaneofpolarization.Athirdpolarizer,withplaneofpolarizationat30°totheoriginalplaneofpolarization,isplacedbetweenthetwootherpolarizers.Whatfractionoftheoriginalintensitynowgetsthrough?()

答案:0.19Offinthedistance,youseetheheadlightsofacar,buttheyareindistinguishablefromthesingleheadlightofamotorcycle.Assumethecar'sheadlightsarenowswitchedfromlowbeamtohighbeamsothatthelightintensityyoureceivebecomesthreetimesgreater.Whatthenhappenstoyourabilitytoresolvethetwolightsources?()

答案:Itremainsthesame.Newtonsringsexperimentisperformedwithairgapbetweenlensandplate.Nowthatgapisfilledwithwater.Whatwillbeeffectonradius(ordiameter)?()

答案:Radius(ordiameter)willdecreaseNewtonsringsexperimentisperformedandradius(ordiameter)iscalculated.NowPlano-convexlensisreplacedwithanotherPlano-convexlensofgreaterRadiusofcurvature.Whatwillbeeffectonradius(ordiameter)?

答案:Radius(ordiameter)willincreaseLightofwavelength540nmisincidentonaslitofwidth0.150mm,andadiffractionpatternisproducedonascreenthatis2.00mfromtheslit.Whatisthewidthofthecentralbrightfringe?()

答案:1.44cmLenz'sLawindicateswhichofthefollowing?()

答案:TheinducedEMFproducesamagneticfieldthatopposesthechangethatproducedtheEMLenz'sismostdirectlyaconsequenceof()

答案:thelawofconservationofenergyInterferencepatternisobservedinwedge-shapedfilmformonochromaticlight.Nowmonochromaticlightisreplacedbywhitelight.Whatwillbetheeffectoninterferencepattern?()

答案:ItwillbeamixtureofallcolorsInterferencepatternisobservedinwedge-shapedfilmandfringewidthisnoted.Nowthethinfilmisreplacedbythefilmofhigherrefractiveindex.Whatwillbetheeffectonfringewidth?()

答案:FringewidthdecreasesInterferencepatternisobservedinwedge-shapedfilmandfringewidthisnoted.Nowtheangleofwedgeisreduced.Whatwillbetheeffectonfringewidth?()

答案:FringewidthincreasesInthinfilmofwedgeshaped,bykeepingallotherparametersconstant,ifonlywavelengthofincidentlightisincreased.Whatwillbetheeffectonbandwidth?

答案:BandwidthincreasesIntheHallEffect,theelectricfieldisinxdirectionandthevelocityisinydirection.Whatisthedirectionofthemagneticfield?()

答案:ZInorderforamagneticfieldtoexertaforceonanobject,whichofthefollowcanbetrue?(

)I.Theobjectischarged.II.Theobjectismovingparalleltothefield.III.Theobjectismovingperpendiculartothefield.

答案:IandIIIonlyInNewtonsringsexperiment,ifwereducetheradiusofcurvatureofPlanoconvexlenstozero,whatwillbeeffectonNewtonsrings?（）

答案:TheywilldisappearInNewtonsringsexperiment,ifmonochromaticsourceoflightisreplacedbyanothermonochromaticsourceofhigherwavelength.Whatwillbetheeffectonradius(ordiameter)?()

答案:Radius(ordiameter)willincreaseIncaseofthinfilmofnon-uniformthickness,whenilluminatedwithwhitelight,thefilmappearscolored.Thisisduetochangeofwhatfactor?()

答案:AllofotherchoicesarepossibleIftwocurrentcarryingwiresexertaforceof50Noneachother,whatforcewilltheyfeelifthedistancebetweenthemishalved?()

答案:100NIftwocurrentcarryingwiresexertaforceof10Noneachother,whatforcewilltheyfeelifthedistancebetweenthemisdoubled?()

答案:5NIfthemagneticfieldBthroughaloopofwireisincreasing,theinducedmagneticfieldwillbe()

答案:intheoppositedirectionasBIfthemagneticfieldBthroughaloopofwireisdecreasing,theinducedmagneticfieldwillbe()

答案:inthesamedirectionasBIfthelightismadeincidentonanytransparentmediumattheBrewsterangle,thetransmittedlightis()

答案:partiallyPolarizedIfthelightismadeincidentonanytransparentmediumattheBrewsterangle,thereflectedlightis()

答案:PlanepolarisedIftheelectricpotentialofasystemisgivenbytheequationV(r)=5ln(r^2),whatistheequationfortheelectricfieldinthissystem?（）

答案:IftheelectricpotentialofasystemisgivenbytheequationV(r)=5ln(r^2),whatistheequationfortheelectricfieldinthissystem?（）IftheelectricfielddoespositiveworkonanegativechargeasthechargeundergoesadisplacementfrompointAtopointBwithinanelectricfield,thentheelectricalpotentialenergy()

答案:decreases.Ifthecurrentinaninductorisdoubled,bywhatfactoristhestoredenergymultiplied?()

答案:4Ifanobjectofmassmattachedtoalightspringisreplacedbyoneofmass9m,thefrequencyofvibratingsystemchangesbywhatmultiplicationfactor?()

答案:1/3Heliumneonlaserlight(632.8nm)issentthroughasingleslitofwidth0.30mm.Whatisthewidthofthecentralmaximumonascreen1.0minbackoftheslit?()

答案:4.2mmGreenlighthasawavelengthof500nminair.Thegreenlightisreflectedperpendicularlyfromathinfilmofaplasticwithanindexofrefraction2.00.Thefilmappearsbrightinthereflectedlight.Howmuchadditionalthicknesswouldmakethefilmappeardark?()

答案:62.5nmGreenlighthasawavelengthof500nminair.Assumegreenlightisreflectedfromamirrorwithangleofincidence0°.Theincidentandreflectedwavestogetherconstituteastandingwavewithwhatdistancefromonenodetothenextnode?()

答案:250nmForamasssuspendedonaspringintheverticaldirection,thetimeforonecompleteoscillationwill

dependon:

答案:thetimedoesn'tdependonthevaluefor

g

or

themaximumspeedoftheoscillatingmass.Electricfieldvectorvibratesinonlyoneplaneandperpendiculartothedirectionofpropagationinwhatlight()

答案:planepolarisedConsiderawavepassingthroughasingleslit.Whathappenstothewidthofthecentralmaximumofitsdiffractionpatternastheslitismadehalfaswide?()

答案:Itbecomestwiceaswide.Coherentlightofasinglefrequencypassesthroughadoubleslitwithaseparationd,toproduceapatternonascreenasdistanceDfromtheslits.Whatwouldcausetheseparationbetweenadjacentminimaonthescreentoincrease?()

答案:increasethedistanceChargesof3.00nC,–2.00nC,–7.00nC,and1.00nCarecontainedinsidearectangularboxwithlength1.00m,width2.00m,andheight2.50m.Outsidetheboxarechargesof1.00nCand4.00nC.Whatistheelectricfluxthroughthesurfaceofthebox?

答案:Chargesof3.00nC,–2.00nC,–7.00nC,and1.00nCarecontainedinsidearectangularboxwithlength1.00m,width2.00m,andheight2.50m.Outsidetheboxarechargesof1.00nCand4.00nC.Whatistheelectricfluxthroughthesurfaceofthebox?Bywhatfactormustonechangetheweightsuspendedverticallyfromaspringcoilinordertotripleitsperiodofsimpleharmonicmotion?()

答案:9.0BasedonLenz'sLaw,theforceonamovingwireloopthatexperiencesachangeinmagneticfluxisalways()

答案:oppositetothedirectionofitsmotionBasedonGauss'Law,whichofthefollowingaffectstheelectricfluxthroughaGaussiansurface?()

答案:astationaryelectricchargeenclosedbythesurfaceBasedonGauss'Law,whichofthefollowingaffectstheelectricfluxthroughaGaussiansurface?()

答案:astationaryelectricchargeenclosedbythesurfaceAtwhatanglewillthesecondordermaximumoccurforawavelengthof400nmusingadiffractiongratingwith10000linespercm?()

答案:53degreeAssumeachangeatthesourceofsoundreducesthewavelengthofasoundwaveinairbyafactorof2.Whathappenstoitsspeed?()

答案:Itisunchanged.Assumeachangeatthesourceofsoundreducesthewavelengthofasoundwaveinairbyafactorof2.Whathappenstoitsfrequency?()

答案:Itincreasesbyafactorof2.Astheslitseparationincreases,whathappenstotheseparationbetweentheinterferencefringesonthescreen?()

答案:Itdecreases.Astheorderincreases,thewidthofadarkbandindiffractionpatterns()

答案:DoesnotchangeAntireflectioncoatingishelpsinwhichcaseofthefollowing?()

答案:MinimizingthereflectionoflightfromtopsurfaceAnunpolarizedbeamoftransversewavesisonewhosevibrations()

答案:OccurinalldirectionsperpendiculartothedirectionofpropagationAnunchargedsolidconductingsphereofradiusrisplacedinauniformelectricfieldofmagnitudeE.Themagnitudeoftheelectricfieldatthecenteroftheconductoris()

答案:0Anunchargedmetalsphereisplacedwithinauniformelectricfield.Whichofthefollowingistrueaboutthenetforceandtorqueonthesphere?（）

答案:Thenetforceandnettorquearebothzero.Anobject-springsystemmovingwithsimpleharmonicmotionhasanamplitudeA.whenitskineticenergyequalstwicethepotentialenergystoredinthespring,whatisthepositionxoftheobject?()

答案:A/√3Anobjectwithachargeof–2qfeelsaforceofFwhenputatapointPinanelectricfield.IntermsofFandq,thestrengthoftheelectricfieldatthispointis().

答案:Anobjectwithachargeof–2qfeelsaforceofFwhenputatapointPinanelectricfield.IntermsofFandq,thestrengthoftheelectricfieldatthispointis().Aninfinitelylargecurrent-carryingsheetliesonthexy-planecarryingcurrentinthey-direction.Whichofthefollowingisfalseaboutthemagneticfieldthatitcreates?()

答案:Themagneticfielddependsonthedistanceawayfromtheplane.Anelectricdipoleismadeupoftwooppositechargeswithequalmagnitudeqseparatedbyadistanced.Midwaybetweenthecharges,theelectricfieldis()

答案:Anelectricdipoleismadeupoftwooppositechargeswithequalmagnitudeqseparatedbyadistanced.Midwaybetweenthecharges,theelectricfieldis()AllofthefollowingaretrueaboutsphericalcapacitorsEXCEPT()

答案:TheelectricfieldbetweenthetwospheresisdeterminedonlybythechargeontheoutersphereAllofthefollowingaretrueaboutGauss'lawEXCEPT()

答案:ArectangleisanexampleofaGaussiansurface.AllofthefollowingaretrueaboutcylindricalcapacitorsEXCEPT()

答案:TheelectricfieldbetweenthetwocylindersisdeterminedbyonlythechargeontheinnercylinderAwireisstretchedbetweentwofixedpointsseparatedbyadistanceL.Whatisthelongestwavelengththatastandingwavecanhaveonthiswire?()

答案:2LAwaveisrepresentedbytheequationy=(1mm)cos(60t+4x),whichoneofthefollowingistrue()

答案:Frequency=30/πAtransversewavetravelsalongthex-axis.Theparticlesofthemediummustmove()

答案:Inthey-zplaneAstraightrodoflength3.0misheldperpendiculartoamagneticfieldof2.0T.Itisrotatedaboutitsmidpointatarateof5.0revolutionspersecond,remainingperpendiculartothefieldtheentiretime.Theemfgeneratedintherodismostnearly()

答案:141VAstandingwaveissetupina200-cmstringfixedatbothends.Thestringvibratesin5distinctsegmentswhendrivenbya120-Hzsource.Whatisthewavelengthofthestandingwave?()

答案:80cmAstandingwavehavingthreenodesissetupinastringfixedatbothends.Ifthefrequencyofthewaveisdoubled,howmanyantinodeswilltherebe?()

答案:5Asourcevibratingatconstantfrequencygeneratesasinusoidalwaveonastringunderconstanttension.Ifthepowerdeliveredtothestringisdoubled,bywhatfactordoestheamplitudechange?()

答案:√2Asolidsphereconsistsofametalcore,anon-conductingmiddleshell,andametaloutershell.Ifapositivechargeisplacedonthecore,whereinthespherewillanetpositivechargebefound?()

答案:onboththeoutersurfaceofthecoreandtheoutersurfaceoftheoutershellAsimplependulumhasamassof0.25kgandalengthof1.0m.Itisdisplacedthroughanangleof30oandthenreleased.Afteratime,themaximumangleofswingisonly10o.Howmuchenergyhasbeenlosttofriction?()

答案:0.29JApolicecarhasasirenwhichwailsatawavelengthλaccordingtoalistenertravellinginthecar.Whatisthewavelengthofthesirenasheardbyapersonstandingonthestreetasthecarapproachesthemataspeedv?Thespeedofsoundinairisc.()

答案:(1-v/c)λAplanemonochromaticlightwaveisincidentonadoubleslitsystem.Astheviewingscreenismovedawayfromthedoubleslit,whathappenstotheseparationbetweentheinterferencefringesonthescreen?()

答案:Itincreases.Aparallel-platecapacitorisconnectedtoabattery.Whathappenstothestoredenergyiftheplateseparationisdoubledwhilethecapacitorremainsconnectedtothebattery?（）

答案:Itdecreasesbyafactorof2.Aparallel-platecapacitorischargedandthenisdisconnectedfromthebattery.Bywhatfactordoesthestoredenergychangewhentheplateseparationisthendoubled?（）

答案:Itbecomestwotimeslarger.Aparallel-platecapacitorhascapacitanceC.Asecondparallel-platecapacitorhasplateswithtwicetheareaandhalftheseparation.Thecapacitanceofthissecondcapacitorismostnearly（）

答案:4CAmassonaspringvibratesinsimpleharmonicmotionatafrequencyof4.0Hzandanamplitudeof8.0cm.Ifthemassoftheobjectis0.20kg,whatisthespringconstant?()

答案:126N/mAmassonaspringvibratesinsimpleharmonicmotionatafrequencyof4.0Hzandanamplitudeof8.0cm.Ifatimerisstartedwhenitsdisplacementisamaximum(hencex=8cmwhent=0),whatisthedisplacementofthemasswhent=3.7s?()

答案:0.025mAmassonaspringvibratesinsimpleharmonicmotionatafrequencyof4.0Hzandanamplitudeof

4.0cm.Ifatimerisstartedwhenitsdisplacementisamaximum(hencex=4cmwhent=0),whatis

theaccelerationmagnitudewhent=3s?

答案:Amassonaspringvibratesinsimpleharmonicmotionatafrequencyof4.0Hzandanamplitudeof

4.0cm.Ifatimerisstartedwhenitsdisplacementisamaximum(hencex=4cmwhent=0),whatis

theaccelerationmagnitudewhent=3s?Amagneticfieldthatisincreasingwithtimeisdirectedoutofthepageandpassesthroughacircularloopofwireintheplaneofthepage.Whichofthefollowingistrue?()

答案:Thereisaninducedcurrentintheloopthatisclockwiseindirection.Amagneticfieldexertsanon-zeroforceonaparticle.Whichofthefollowingmustbetrue?()

答案:Thedirectionoftheforceisperpendiculartoboththevelocityoftheparticleandthemagneticfield.Aloopofwireformsarighttrianglewithlegsoflength3mand4m.Theloopisplacedinamagneticfieldof5Tata45°tothemagneticfield.Whatisthemagneticfluxthroughtheloop?（）

答案:Aloopofwireformsarighttrianglewithlegsoflength3mand4m.Theloopisplacedinamagneticfieldof5Tata45°tothemagneticfield.Whatisthemagneticfluxthroughtheloop?（）Along,vertical,metallicwirecarriesdownwardelectriccurrent.Whatisthedirectionofthemagneticfielditcreatesatapoint2cmhorizontallyeastofthecenterofthewire?()

答案:northAlong,finewireiswoundintoacoilwithinductance5mH.Thecoilisconnectedacrosstheterminalsofabattery,andthecurrentismeasuredafewsecondsaftertheconnectionis