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最全APomni_xyz最全APomni_xyzObtainedObtainedfromopen.773.im/CommercialUse APAP®PhysicsC:ElectricityandMagnetismPracticeTheThequestionscontainedinthisAP®PhysicsC:ElectricityandMagnetismPracticeExamarewrittentothecontentspecificationsofAPExamsforthissubject.TakingthispracticeexamshouldprovidestudentswithanideaoftheirgeneralareasofstrengthsandweaknessesinpreparingfortheactualAPExam.BecausethisAPPhysicsC:ElectricityandMagnetismPracticeExamhasneverbeenadministeredasanoperationalAPExam,statisticaldataarenotavailableforcalculatingpotentialrawscoresorconversionsintoAPgrades.ThisAPPhysicsC:ElectricityandMagnetismPracticeExamisprovidedbytheCollegeBoardforAPExampreparation.Teachersarepermittedtodownloadthematerialsandmakecopiestousewiththeirstudentsinaclassroomsettingonly.Tomaintainthesecurityofthisexam,teachersshouldcollectallmaterialsaftertheiradministrationandkeeptheminasecurelocation.Teachersmaynotredistributethefileselectronicallyforanyreason.©betr08TheCollegeBoard.AllrightsrCollegeBoard,AdvancedPementProgram,AP,AP©betr最全APo-最全APo-ni_xyzObtainedObtainedfromopen.773.im/CommercialUseDirectionsfor SectionI:Multiple-Choice SectionII:-Response StudentAnswerSheetforMultiple-Choice Multiple-ChoiceAnswer -ResponseScoring TheCollegeBoard:ConnectingStudentstoCollegeTheCollegeBoardisanot-for-profitmembershipassociationwhosemissionistoconnectstudentstocollegesuccessandopportunity.Foundedin1900,theassociationiscomposedofmorethan5,000schools,colleges,universities,andothereducationalorganizations.Eachyear,theCollegeBoardservessevenmillionstudentsandtheirparents,23,000highschools,and3,500collegesthroughmajorprogramsandservicesincollegeadmissions,guidance,assessment,financialaid,enrollment,andteachingandlearning.Amongitsbest-knownprogramsaretheSAT®,thePSAT/NMSQT®,andtheAdvancedcementProgram®(AP®).TheCollegeBoardiscommittedtotheprinciplesofexcellenceandequity,andthatcommitmentisembodiedinallofitsprograms,services,activities,andconcerns.sittheCollegeBoardonthe CentralistheofficialonlinehomefortheAPProgram: 最全APii最全APii-Obtainedfromopen.773.imObtainedfromopen.773.im/CommercialUseTheAPPhysicsC:ElectricityandMagnetismExamisoneandone-halfhoursinlengthandconsistsofamultiple-choicesectionanda -responsesection.The45-minutemultiple-choicesectioncontains35questionsandaccountsfor50percentofthefinalThe45- -responsesectioncontains3questionsandaccountsfor50percentofthefinalStudentsshouldbegivena10-minutewarningpriortotheendofeachsectionoftheexam.A10-minutebreakshouldbeprovidedbeforeSectionIisbegunifstudentsaretakingPhysicsC:MechanicsimmediaybeforeElectricityandMagnetism.TheactualAPPhysicsCExamsareadministeredinonesession,MechanicsfirstfollowedbyElectricityandMagnetism.Studentstakingonlyoneoftheexamswillhavethemostrealisticexperienceifbothsectionsarecompletedinonesession.Similarly,studentstakingbothPhysicsCexamswillhavethemostrealisticexperienceifbothexamsarecompletedinonesessionandacompletemorningorafternoonisavailabletoadministerthem.Ifascheduledoesnotpermitonetimeperiodforadministration,itwouldbeacceptabletoadministerMechanicsononedayandElectricityandMagnetismonasubsequentday,ortofurtherbreakthingsupandadministerSectionIandSectionIIofeachexamonsubsequentdays.Manystudentswonderwhetherornottoguesstheanswerstothemultiple-choicequestionsaboutwhichtheyarenotcertain.Itisimprobablethatmereguessingwillimproveascore.However,ifastudenthassomeknowledgeofthequestionandisabletoeliminateoneormoreanswerchoicesaswrong,itmaybetothestudent’sadvantagetoanswersuchaquestion.TheuseofcalculatorsispermittedonlyonSectionII.Straightedgesorrulersareallowedonbothpartsoftheexam.ItissuggestedthatthepracticeexambecompletedusingapenciltosimulateanactualTeacherswillneedtoprovidepaperforthestudentstowritetheir-responseanswers.Teachersshouldprovidedirectionstothestudentsindicatinghowtheywishtheresponsestobelabeledsotheteacherwillbeabletoassociatethestudent’sresponsewiththequestionthestudentintendedtoanswer.The2008–2009APPhysicsCtableofinformationisincludedasapartofSectionI.ThetableandtheAPPhysicsCequationlistsareincludedwithSectionII.TheequationlistsarenotallowedforSectionI.IfyouusetheseexamsinsubsequentyearsyoushoulddownloadthenewerversionsofthetableandlistsfromAPCentral.Rememberthatstudentsarenotallowedtoremoveanymaterials,includingscratchwork,fromthetesting最全APo-PAGE最全APo-ni_xyz扫描左下ObtainedObtainedfromopen.773.im/CommercialUseSectionIMultiple-ChoiceQuestionsObtainedfromopen.773.im/CommercialUseCONSTANTSANDCONVERSIONProtonmass,mpObtainedfromopen.773.im/CommercialUseCONSTANTSANDCONVERSIONProtonmass,mp=1.67¥027kgNeutronmass,mn=1.67¥027kgElectronmass,me=9.11¥031kgAvogadro’snumber,N0=6.02¥1023mol-Universalgasconstant,R=8.31JBoltzmann’sconstant,kB=1.38¥023JElectronchargemagnitude,e=1.60¥019C1electronvolt,1eV=1.60¥019JSpeedoflight,c=3.00¥108msUniversalgravitationalG=6.67¥10-11m3Accelerationdueto g=9.8matEarth’s1unifiedatomicmass 1u=1.66¥027kg=931MeVnck’s h=6.63¥034Jis=4.14¥015hc=1.99¥025Jim=1.24¥103Vacuum 0=8.85¥012C2Nim2Coulomb’slawconstant,k=14p0=9.0¥109Nim2C2Vacuum m0=4p¥07(Tim)Magneticconstant,k¢=m04p=07(Tim)1atmosphere 1atm=1.0¥105Nm2=1.0¥105mWFAJWdegreeelectron-TmWFAJWdegreeelectron-TKHVALUESOFTRIGONOMETRICFUNCTIONSFORCOMMONqD0sin01324310033143•GMk10- 10- 10- 10- 10- Unlessotherwisestated,theframeofreferenceofanyproblemisassumedtobeinertial.Thedirectionofanyelectriccurrentisthedirectionofflowofpositivecharge(conventionalcurrent).Foranyisolatedelectriccharge,theelectricpotentialisdefinedaszeroataninfinitedistancefromthecharge.GOONTOTHEGOONTOTHENEXT最全APo-ni_xyz扫描左下PHYSICSC:ELECTRICITYANDMAGNETISMSECTIONITime—45minutes35QuestionsDirections:Eachofthequestionsor pletestatementsbelowisfollowedbyfivesuggestedanswersorcompletions.Selecttheonethatisbestineachcaseandcetheletterofyourchoiceinthecorrespondingboxonthestudentanswersheet.TwonegativepointchargesareadistancexapartandhavepotentialenergyU.Ifthedistancebetweenthepointchargesincreasesto3x,whatistheirnewpotentialenergy?UUUAnelectricfieldisproducedbytheverylong,

Questions3-Twoconcentricsphericalsurfacesaredrawnaroundanisolatedpositivecharge+qlocatedattheircenter,asshownabove.Theinnersurfacehasaradiusthatis12thatoftheoutersurface.throughtheoutersurface?oftheelectricfield

E1atadistance

ftheaxisoftherod,atwhatdistancefromtheaxis

fthefield

214rr2

4IftheelectricfieldstrengthattheinnerisE,whatistheelectricfieldstrengthattheouter

E

EObtainedObtainedfromopen.773.im/CommercialUse

SphereXofmassMandcharge+qhangsfromastringasshownabove.SphereYhasanequalcharge+qandisfixedinceadistanced

Acharge+qiscedatthecenterofatetrahedronwhosefacesareallequilaltriangles,asshownabove.Whatisthefluxoftheelectricfieldthroughonefaceofthe0q0directlybelowsphereX.IfsphereXisinequilibrium,thetensioninthestringismost

4

Mg+d

Thefluxthroughonefacecannotdeterminedfromtheinformation

Mg-dObtainedObtainedfromopen.773.im/CommercialUse

MgMg

TwoconcentricmetalspheresXandYareshownabove.Xcarriesapositivecharge,andYisconnectedtoground.Truestatementsincludewhichofthefollowing?TheelectricfieldinsideXisTheelectricfieldoutsideYisThechargedensityonbothspheresisthesame.IIIIIandIIIIandIIII,II,and9.ThecapacitorCinthecircuitshownaboveisinitiallyuncharged.TheswitchSisthenclosed.WhichofthefollowingbestrepresentsthevoltageObtainedObtainedfromopen.773.im/CommercialUsewithouttouchingtheinsidesurfaceofthecup,asshownabove.Thegroundingwireattachedtotheoutsidesurfaceisdisconnectedandthechargedsphereisthenremovedfromthecup.Whichofthefollowingbestdescribesthesubsequentdistributionofexcesschargeonthesurfaceofthecup?Negativechargeresidesontheinsidesurface,andnochargeresidesontheoutsideNegativechargeresidesontheoutsidesurface,andnochargeresidesontheinsidePositivechargeresidesontheinsidesurface,andnochargeresidesontheoutsidePositivechargeresidesontheoutsidesurface,andnochargeresidesontheinsidesurface.Negativechargeresidesontheinsidesurface,andpositivechargeresidesontheoutside

acrosstheresistorRasafunctionoftimetObtainedfromopen.773.imObtainedfromopen.773.im/CommercialUseAnelectriccircuitconsistsofa12Vbattery,anideal10Afuse,andthree2Wresistorsconnectedasshownabove.WhatwouldbethereadingonavoltmeterconnectedacrosspointsAandC?126320V,sincethefusewouldbreaktheWhatwouldbethereadingonanammeterinsertedatpointB?96320A,sincethefusewouldbreaktheAfixedvoltageisappliedacrossthelengthofatungstenwire.Anincreaseinthepowerdissipatedbythewirewouldresultifwhichofthefollowingcouldbeincreased?TheresistivityoftheThecross-sectionalareaoftheThelengthoftheThetemperatureoftheThetemperatureofthewire’s

Thethreelightbulbsinthecircuitaboveareidentical,andthebatteryhaszerointernal.WhenswitchSisclosedtocausebulb1tolight,whichoftheothertwobulbsincrease(s)inbrightness?NeitherBulb2Bulb3BothItcannotbedeterminedwithoutknowingtheemfofthebattery.AlengthofwireofRisconnectedacrossabatterywithzerointernal.Thewireisthencutinhalfandthetwohalvesareconnectedinparallel.Whenthecombinationisreconnectedacrossthebattery,whathappenstotheresultantpowerdissipatedandthecurrentdrawnfromthebattery? No No Inthecircuitshownabove,the10mFisinitiallyuncharged.AftertheswitchShasbeenclosedforalongtime,howmuchenergyisstoredinthecapacitor?01002505001000ObtainedObtainedfromopen.773.im/CommercialUseAnelectronemovinginthe neofthepageisinjectedintoauniformmagneticfieldBthatisperpendiculartothepage,asshownabove.Uponenteringthefield,theelectrontakesapaththatisstraightthroughtheclockwise,circular,andintheneofthepagecounterclockwise,circular,andintheneofthepagecircularandcurvedoutofthecircularandcurvedintotheInthefigureabove,twolong,straight,insulatedwiresatrightanglesintheneofthepagecarrycurrentsofIand2I,asshown.WhatisthedirectionofthemagneticfieldatpointP,whichisequidistantfromthewiresandconarwithIntotheOutofthepage(C)(D)

Questions18-Afixedchargedistributionproducestheequipotentiallinesshowninthefigureabove.WhichofthefollowingexpressionsbestrepresentsthemagnitudeoftheelectricfieldatpointP?100.14100.04250.14250.04400.25ThedirectionoftheelectricfieldatpointPismostnearlytowardthetowardthetowardthebottomofthetowardthetopoftheperpendiculartotheneoftheGOONTOGOONTOTHENEXT最全APo-ni_xyz扫描左下Aheliumnucleus(charge+2qandmass4m)andalithiumnucleus(charge+3qandmass7m)areacceleratedthroughthesameelectricpotentialdifference,V0.Whatistheratiooftheirresultant

Questions23-AcloudcontainssphericaldropsofofradiusRandchargeQ.Assumethedropsarefarapart.kinetic

Klithium

TheelectricfieldEandpotentialVat 2367176

surfaceofeachdropisgivenbywhichof 32

Theelectricpotentialinthexy-neina

RregionofspaceisgivenbyV(x,y)=6x2y-2y3,wherexandyareinmetersandVisinvolts.Whatisthemagnitudeof ponentof

Relectricfieldatthepoint(-1,2)0

Iftwodropletshappentocombineintoasinglelargerdroplet,thenewpotentialVatthesurfaceofthelargerdropletismostnearlyequalto182430

2Twoprotonsandanelectronareassembledalongaline,asshownabove.Thedistancebetweentheelectronandeachprotonisa.Whatistheworkdonebyanexternalinassemblingthisconfigurationofcharges?

21/ -a

-32ObtainedObtainedfromopen.773.im/CommercialUse22 322 3ke2

1GOONTOTHEGOONTOTHENEXT最全APo-ni_xyz扫描左下ApointchargeQislocatedattheorigin,whileasecondpointcharge+2Qislocatedatx=donthex-axis,asshownabove.Apointonthex-axiswherethenetelectricfieldiszeroislocatedinwhichofthefollowingregions?

Questions27-Anemfof20Visinducedaroundametalringbyincreasingauniformmagneticfieldataconstantfromzerotoafinalmagnitudeof1.0¥02Tthroughouttheregionenclosedbythering.Thefielddirectionisperpendiculartotheneofthering.Iftheareaenclosedbytheringis4.0¥03m2

-•<x<

whatisthetimeintervalduringwhichthefieldisincreased?0<x<2d

2.05.02<x<

10d<x<Noregiononthex-AninductorofinductanceLisconnectedserieswitharesistorofR,abatteryofemfe,andaswitch,asshownabove.Whenswitchisclosed,thecurrentIinthecircuitincreaseswithtime,approachingthevalueImax.WhatisImax?RRLee

2050Iftheelectrical oftheringis500,whatistherateatwhichenergyisdissipatedintheringasthefieldisincreased?0.0400.801.25251.0¥104Obtainedfromopen.773.imObtainedfromopen.773.im/CommercialUseGOONTOGOONTOTHENEXT最全APo-ni_xyz扫描左下Twolong,straightwiresareparalleltoandequidistantfromthey-axis,asshownaboveleft.EachcarriescurrentIinoppositedirections,resultinginamagneticfieldofmagnitudeB0attheorigin.Ifthewiresareeachbentintorightanglesandcedasshownaboveright,whatisthemagnitudeofthemagneticfieldattheorigin?BBetweenzero B2B0B2B B2

andObtainedfromObtainedfromopen.773.im/CommercialUseAlengthofwirecarryingasteadyclockwisecurrentIisbenttoformthetriplecircularloopXabove.AnidenticallengthofthesamewireisbentlesstightlytoformthesingleloopYoflargerradius,whichcarriesthesamecurrentI.TheratioofthemagneticfieldstrengthatthecenterofloopYtothemagneticfieldstrengthatthecenterofloopXis(A)9(B)3(C)(D)(E)GOONTOTHEGOONTOTHENEXT最全APo-ni_xyz扫描左下32.AlongwireofradiusRcarriesacurrentI,shownabove,withacurrentdensityJ=arThediagramaboveshowsthecrosssectionofalongcablethathasaninnerwireofradiusRsurroundedbyaconductingsheathofouterradius2R.ThewireandthesheathcarrycurrentsinoppositedirectionsbutwiththesameuniformcurrentdensityJ.Whatisthemagnitudeofthemagneticfieldatthesurfaceoftheouter

increaseslinearlywiththedistancerfromthecenterofthewire.WhichofthefollowinggraphsbestrepresentsthemagnitudeofthemagneticfieldBasafunctionr?

1m

41m23m4ObtainedObtainedfromopen.773.im/CommercialUse

m0

最全APo-PAGE最全APo-ni_xyz扫描左下Inthecircuitdrawnabove,theswitchSisinitiallyopen,andthecapacitorCischargedwiththepolarityindicated.Theswitchisthenclosed,andthecapacitorbeginsdischargingthroughtheresistor.Whichofthefollowingistrueofthecurrentthatissubsequentlyinducedinthecircularwireloopnearthelong,straightwireAB?ItiscounterclockwiseandItiscounterclockwiseandincreaseswithtime.Itiscounterclockwiseanddecreaseswithtime.ItisclockwiseandincreaseswithItisclockwiseanddecreaseswith

WhichofthefollowingstatementscontradictsoneofMaxwell’sequations?Achangingmagneticfieldproducesanelectricfield.AchangingelectricfieldproducesamagneticThenetmagneticfluxthroughaclosedsurfacedependsonthecurrentinside.Thenetelectricfluxthroughaclosedsurfacedependsonthechargeinside.Theelectricfieldduetoanisolatedstationarypointchargeisinverselyproportionaltothesquareofthedistancefromthecharge.AstudentbuildingacircuitwishestoincreasetheofcapacitanceCandaninductorofinductanceL.Whichofthefollowingwould plishthisIncreaseIncreaseDecreaseDecreaseIIorIorIIorIIIorObtainedObtainedfromopen.773.im/CommercialUseSTOENDOFELECTRICITYANDMAGNETISMSECTIONIIFYOUFINISHBEFORETIMEISCALLED,YOUMAYCHECKYOURWORKONELECTRICITYANDMAGNETISMSECTIONIONLY.DONOTTURNTOANYOTHERTESTMATERIALS.ObtainedObtainedfromopen.773.im/CommercialUseSection-ResponseObtainedfromopen.773.im/CommercialUseTABLEOFINFORMATIONFOR2008andObtainedfromopen.773.im/CommercialUseCONSTANTSANDCONVERSIONProtonmass,mp=1.67¥027kgNeutronmass,mn=1.67¥027kgElectronmass,me=9.11¥031kgAvogadro’snumber,N0=6.02¥1023mol-Universalgasconstant,R=8.31JBoltzmann’sconstant,kB=1.38¥023JElectronchargemagnitude,e=1.60¥019C1electronvolt,1eV=1.60¥019JSpeedoflight,c=3.00¥108msUniversalgravitationalG=6.67¥10-11m3Accelerationdueto g=9.8matEarth’s1unifiedatomicmass 1u=1.66¥027kg=931MeVnck’s h=6.63¥034Jis=4.14¥015hc=1.99¥025Jim=1.24¥103Vacuum 0=8.85¥012C2Nim2Coulomb’slawconstant,k=14p0=9.0¥109Nim2C2Vacuum m0=4p¥07(Tim)Magneticconstant,k¢=m04p=07(Tim)1atmosphere 1atm=1.0¥105Nm2=1.0¥105mWFAJWdegreeTKHVALUESOFTRIGONOMETRICFUNCTIONSFORCOMMONqD0DDDDDsin01324310033143•GMk10- 10- GMk10- 10- 10- 10- 10- Unlessotherwisestated,theframeofreferenceofanyproblemisassumedtobeinertial.Thedirectionofanyelectriccurrentisthedirectionofflowofpositivecharge(conventionalcurrent).Foranyisolatedelectriccharge,theelectricpotentialisdefinedaszeroataninfinitedistancefromthecharge.最全APo-最全APo-ni_xyz扫描左下ADVANCEDCEMENTPHYSICSCEQUATIONSFOR2008and u=u0+

a=F

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FM=qv¥bqcbqcObtainedfromopen.773.im/CommercialUseCEMENTPHYSICSCEQUATIONSFOR2008andÚcosxdx=sinÚsinxdx=-cos=lnxÚexdx=Ú1n ,nπn+nxdxÚd(cosx)=-sind(sinx)=cosxd(1nx)=d(ex)=d(xn)=nxn- dudf=dfbtanq=accosqsinq=V=43S=Righta2+b2=A=C=V=S=surfaceb=baseh=heightA=lengthw=widthr=radiusA=C=2prV=AwhV=S=2prA+2A=1GEOMETRYANDA=GOONTOGOONTOTHENEXT最全APo-ni_xyz扫描左下PHYSICSC:ELECTRICITYANDMAGNETISMSECTIONIITime—45Directions:Answerallthreequestions.Thesuggestedtimeisabout15minutesforansweringeachofthequestions,whichareworth15pointseach.Thepartswithinaquestionmaynothaveequalweight.Allfinalnumericalanswersshouldincludeappropriateunits.Creditdependsonthequalityofyoursolutionsandexnations,soyoushouldshowyourwork.Creditalsodependsondemonstratingthatyouknowwhichphysicalprincipleswouldbeappropriatetoapplyinaparticularsituation.Therefore,youshouldclearlyindicatewhichpartofaquestionyourworkisfor.E&M.Aparallel-tecapacitorX,withteareaAandteseparationd,isfilledwithairandchargedbyconnectingthecapacitorthroughaswitchtoapowersupplyofemfe,asshownabove.Determinethemagnitudeofthechargeq0oneachteofthecapacitor,intermsofthegiventiesandfundamentalconstants.Theswitchisnowflippedtotheright,sothatcapacitorXisdisconnectedfromthepowersupplyandisinsteadconnectedtoanunchargedparallel-tecapacitorY.CapacitorYhasthesameteseparationbuttwicetheteareaandisfilledwithamaterialhavingdielectricconstant3.Calculatetheequilibriumchargestheinitialchargeq0

and

oncapacitorsXandY,expressingyouranswersintermsOncethechargesonthetwocapacitorshavereachedequilibrium,theyaredisconnectedfromoneanother.ThedielectricisthenremovedfromcapacitorY.IndicatewhethertheenergystoredincapacitorYasthedielectricisremovedincreases,decreasesorremainsthesame. RemainsthesameJustifyyouranswer.Indicatewhetheryouranswerto(c)requiresthattheelectriconthedielectricasitisremovedpullsthedielectricintothecapacitor,pushesitout,oriszero. Pullsitin PushesitoutJustifyyouranswer.

IsAresistorofRisnowconnectedtothetwosidesofcapacitorY.Thecapacitorisallowedtodischargethroughtheresistor.DerivetheequationdescribingthechargeoncapacitorYasafunctionoftime,Obtainedfromopen.773.im/CommercialUsepressedintermsofR,d,time,Obtainedfromopen.773.im/CommercialUse

oncapacitorY,andfundamentalE&M.Electronscreatedatthefilamentattheleftendofthetuberepresentedaboveareacceleratedthroughavoltageandexitthetube.Theelectronsthenmovewithconstantspeedtotheright,asshown,beforeenteringaregioninwhichthereisauniformelectricfieldbetweentwo tesseparatedbyadistanceD.TheelectronsthefieldatpointP,whichisa

y0fromthe te,andaredeflectedtowardthatte.youranswerstothefollowingintermsofV0,D,y0,andfundamentalCalculatethespeedoftheelectronsastheyexitthei.Calculatethemagnitudeoftheelectricfieldrequiredtocausetheelectronstolandthedistancetheedgeofthete.Indicatethedirectionoftheelectric Tothe Tothe Towardthetopofthe Towardthebottomofthe Intothepage OutofthepageJustifyyouranswer.

y0Calculatethepotentialdifferencebetweenthetwotesrequiredtoproducetheelectricfielddeterminedinpart(b).Supposetheelectricfieldbetweenthetesisrecedbyamagneticfieldandtheelectronsaretostrikelowerteatthesame

y0fromtheedgeoftheObtainedObtainedfromopen.773.im/CommercialUsei.CalculatethemagnitudeofthemagneticIndicatethedirectionoftherequiredmagnetic Tothe Tothe Towardthetopofthe Towardthebottomofthe Intothepage OutofthepageJustifyyouranswer.最全APo-PAGE最全APo-ni_xyz扫描左下E&M.Anastronauton neterectsatall,thin,vertical,nonconducting,frictionlesscylinderofradiusr0atofthenet’smagneticpoles.AssumethemagneticfieldhasanupwardverticalcomponentwithathatvarieswithaltitudezasBz=B0(1-kz),wherekisaconstant.Thehorizontalcomponentofthefieldtheconstantvalue

atthesurfaceofthecylinderandpointsradiallyoutwardfromtheaxisoftheObtainedfromopen.773.im/CommercialUseAgoldringofRthatjustfitsaroundthecylinderisreleasedfromrestatsomeheightabovetheground.Assumeairfrictionisnegligible.ExpressallalgebraicanswersintermsofB0,BHObtainedfromopen.773.im/CommercialUseDeterminethemagneticfluxthroughtheringasafunctionofzIndicatewhetherthedirectionoftheinducedcurrentinthering,asseenfromabovethecylinder,isclockwiseorcounterclockwise. Justifyyouranswer.CalculatethepowerdissipatedintheringattheinstantitisfallingwithspeeduCalculatethemagnitudeofthenetupwardontheringduetothehorizontalcomponentofthefieldattheinstanttheringisfallingwithspeedu.Isthereanetontheringduetotheverticalcomponentofthefield?ExinyourENDOFEXAMObtainedfromObtainedfromopen.773.im/CommercialUseAP®PhysicsC:ElectricityandMagnetismStudentAnswerSheetforMultiple-ChoiceSection 123123456789AP®PhysicsC:ElectricityandMagnetismMultiple-ChoiceAnswerKey

ObtainedfromObtainedfromopen.773.im/CommercialUse1D2D3C4A5E6C7C8B9DACBCEDBBBAECBCCADABCACCECEAP®PhysicsC:Electricityand-ResponseScoringGeneralNotesaboutAPPhysicsPracticeExamScoringThesolutionscontainacommonmethodofsolvingthe-responsequestionsandtheallocationofpointsforthesolutions.Somealsocontainacommonalternatesolution.Theyaretypicalofdraftguidelinesdevelopedbeforestudentsolutionsareavailable.Teachersshouldfeeltomakemodificationsbasedontheirstudents’responses.Thescoringguidelinestypicallyshownumericalresultsusingthevalueg=9.8ms2,butuse10m

isofcoursealsoacceptable.SolutionsusuallyshownumericalanswersusingbothObtainedfromopen.773.im/CommercialObtainedfromopen.773.im/CommercialUseThefollowingrulesapplytotheofficialscoringofAPPhysicsAllcorrectmethodsofsolutionreceiveappropriatecreditforcorrectGenerally,doublepenaltyforerrorsisavoided.Forexample,ifanincorrectanswertopart(a)iscorrectlysubstitutedintoanotherwisecorrectsolutiontopart(b),fullcreditwillusuallybeawarded.Oneexceptiontothismaybecaseswhenthenumericalanswertoalaterpartshouldbeeasilyrecognizedaswrong,e.g.,aspeedfasterthanthespeedoflightinvacuum.Implicitstatementsofconceptsnormallyreceivecredit.Forexample,ifuseoftheequationexpressingaparticularconceptisworth1point,andastudent’ssolutioncontainstheapplicationofthatequationtotheproblembutthestudentdoesnotwritethebasicequation,thepointisstillawarded.However,whenstudentsareaskedtoderiveanexpression,itisnormallyexpectedthattheywillbeginbywritingoneormorefundamentalequations,suchasthosegivenontheAPPhysicsExamequationsheet.Foradescriptionoftheuseofsuchtermsas“derive”and“calculate”ontheexams,andwhatisexpectedforeach,see“The -ResponseSectionsStudentPresentation”intheAPPhysicsCourseDescription.Strictrulesregardingsignificantdigitsareusuallynotappliedtonumericalanswers.However,insomecasesanswerscontainingtoomanydigitsmaybepenalized.Ingeneral,twotofoursignificantdigitsareacceptable.Numericalanswersthatdifferfromthepublishedanswerduetodifferencesinroundingthroughoutthequestiontypicallyreceivefullcredit.Exceptionstotheseguidelinesusuallyoccurwhenroundingmakesadifferenceinobtainingareasonableanswer.Forexample,supposeasolutionrequiressubtractingtwonumbersthatshouldhavefivesignificantfiguresandthatdifferstartingwiththedigit(e.g.,20.295and20.278).Roundingtothreedigitswilllosetheaccuracyrequiredtodeterminethedifferenceinthenumbers,andsomecreditmaybelost.AP®PhysicsC:Electricityand-ResponseScoring15points of2Forusingtheexpressionsrelatingchargetoemfandcapacitancetocapacitor 1q0=C=0dForthecorrect 1q=0A 5Forcorrectuseofconservationof 1qX+qY=Forindicatingthatatequilibriumthevoltageisthesameacrosseach 1 =

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Question1(

ofpointsForcorrectlyindicatingthatthestoredenergyincreasesasthedielectricisremoved 1pointForavalid