现代物理学知到智慧树章节测试课后答案2024年秋苏州大学

现代物理学知到智慧树章节测试课后答案2024年秋苏州大学第一章单元测试

Asahigh-speedspaceshipfliespastyou,itfiresastrobelightthatsendsoutapulseoflightinalldirections.Anobserveraboardthespaceshipmeasuresasphericalwavefrontthatspreadsawayfromthespaceshipwiththesamespeedinalldirections.Whatistheshapeofthewavefrontthatyoumeasure?（）

A:notenoughinformationisgiventodecide.B:ellipsoidal,withtheshortestaxisoftheellipsoidalongthedirectionofthespaceship’smotionC:sphericalD:ellipsoidal,withthelongestaxisoftheellipsoidalongthedirectionofthespaceship’smotion;

答案:sphericalStanley,whoworksfortherailsystem,hascarefullysynchronizedtheclocksatalloftherailstations.AtthemomentthatStanleymeasuresalloftheclocksstrikingnoon,Mavisisonahigh-speedpassengercartravelingfromOgdenvilletowardNorthHaverbrook.AccordingtoMavis,whentheOgdenvilleclockstrikesnoon,whattimeisitinNorthHaverbrook?（）

A:beforenoonB:notenoughinformationisgiventodecideC:afternoonD:noon

答案:afternoonSamir(whoisstandingontheground)startshisstopwatchattheinstantthatMariafliespasthiminherspaceshipataspeedof0.600c.Atthesameinstant,Mariastartsherstopwatch.AsmeasuredinSamir’sframeofreference,whatisthereadingonMaria’sstopwatchattheinstantthatSamir’sstopwatchreads10.0s?（）

A:morethan10.0sB:lessthan10.0sC:10.0sD:notenoughinformationisgiventodecide

答案:lessthan10.0sInframeSeventsP1andP2occuratthesamex-,y-andz-coordinates,buteventP1occursbeforeeventP2.InframeS’,eventP1occursfirst。（）

A:错B:对

答案:对Accordingtorelativisticmechanics,whenyoudoublethespeedofaparticle,themagnitudeofitsmomentumincreasesby（）

A:afactorgreaterthan2B:afactorof2C:afactorsmallerthan1D:afactorbetween1and2thatdependsonthemassoftheparticle

答案:afactorgreaterthan2

第二章单元测试

Siliconfilmsbecomebetterelectricalconductorswhenilluminatedbyphotonswithenergiesof1.14eVorgreater,aneffectcalledphotoconductivity.Whichofthefollowingwavelengthsofelectromagneticradiationcancausephotoconductivityinsiliconfilms?（）

A:ultravioletlightwithλ=300nmB:infraredlightwithλ=1200nmC:redlightwithλ=600nm

答案:ultravioletlightwithλ=300nm；redlightwithλ=600nmIntheapparatususedtoproducexrays,similartoRöntgen’s1895apparatus,supposeyouincreasethenumberofelectronsthatareemittedfromthecathodepersecondwhilekeepingthepotentialdifferenceVACthesame.HowwillthisaffecttheintensityIandminimumwavelengthλminoftheemittedxrays?（）

A:noneoftheseB:IwillincreasebutλminwillbeunchangedC:IwillremainthesamebutλminwilldecreaseD:IwillincreasebutλminwilldecreaseE:Iandλminwillbothincrease

答案:IwillincreasebutλminwillbeunchangedIfyouusedvisible-lightphotonsintheCompton-effectexperiment,thephotonswouldundergoawavelengthshiftduetothescattering.（）

A:对B:错

答案:对Ifyouusedvisible-lightphotonsintheCompton-effectexperiment,itispossibletodetecttheshiftwiththehumaneye。（）

A:错B:对

答案:错Throughwhichofthefollowinganglesisaphotonofwavelengthλmostlikelytobedeflectedafterpassingthroughaslitofwidtha?Assumethatismuchlessthana.（）

A:θ=λ/aB:notenoughinformationgiventodecideC:θ=3λ/aD:θ=3λ/2aE:θ=2λ/a

答案:θ=3λ/2a

第三章单元测试

Aprotonhasaslightlysmallermassthananeutron.Comparedtotheneutron,wouldaprotonofthesamewavelengthhave（）?（）

A:lesskineticenergyB:thesamekineticenergyC:morekineticenergy

答案:morekineticenergySupposeyourepeatedRutherford’sscatteringexperimentusingathinsheetofsolidhydrogeninplaceofthegoldfoil.(Hydrogenisasolidattemperaturesbelow14.0K.)Thenucleusofahydrogen

atomisasingleproton,withaboutone-fourththemassofanalphaparticle.Comparedto

theoriginalexperimentwithgoldfoil,wouldyouexpectthealphaparticlesinthisexperiment

toundergo（）？（）

A:lesslarge-anglescatteringB:thesameamountoflarge-anglescatteringC:morelarge-anglescattering

答案:lesslarge-anglescatteringConsiderthepossibletransitionsbetweenenergylevelsinaHe+ion.ForwhichofthesetransitionsinHe+willthewavelengthoftheemittedphotonbenearlythesameasoneofthewavelengthsemittedbyexcitedHatoms？（）

A:n=2ton=1B:n=3ton=2C:morethanoneoftheseD:n=4ton=3E:noneofthese

答案:morethanoneoftheseAnordinaryneonlightfixturelikethoseusedinadvertisingsignsemitsredlightofwavelength632.8nm.Neonatomsarealsousedinahelium–neonlaser(atypeofgaslaser).Thelightemittedbyaneonlightfixtureis（）

A:bothspontaneousandstimulatedemissionB:spontaneousemissionC:stimulatedemission

答案:spontaneousemissionAblackbodyat2000Kemitsxraysanditalsoemitsradiowaves.（）

A:对B:错

答案:对

第四章单元测试

Awavepacketgivenbythisequation，，representsastationarystate.（）

A:对B:错

答案:错Ifaparticleinaboxisinthenthenergylevel,whatistheaveragevalueofitsx-componentofmomentumpx?（）

A:B:zeroC:D:E:

答案:zeroSupposethatthewidthofthefinitepotentialwellisreducedbyone-half.HowmustthevalueofU0changesothattherearestilljustthreeboundenergylevelswhoseenergiesarethefractionsofU0?U0must:（）？（）

A:remainthesameB:increasebyafactoroftwoC:increasebyafactoroffourD:decreasebyafactorofone-fourthE:decreasebyafactorofone-half

答案:increasebyafactoroffourItispossibleforaparticleundergoingtunnelingtobefoundwithinthebarrierratherthanoneithersideofit.（）

A:错B:对

答案:对Aquantum-mechanicalsysteminitiallyinitsgroundlevelabsorbsaphotonandendsupinthefirstexcitedstate.Thesystemthenabsorbsasecondphotonandendsupinthesecondexcitedstate.Forwhichofthefollowingsystemsdoesthesecondphotonhavealongerwavelengththanthefirstone?（）

A:ahydrogenatomB:aharmonicoscillatorC:aparticleinabox

答案:ahydrogenatom

第五章单元测试

Inacertainregionofspacethepotential-energyfunctionforaquantum-mechanicalparticleiszero.Inthisregionthewavefunctionforacertainstationarystatesatisfies,,and.TheparticlehasadefiniteenergyEthatispositive.Whatcanyouconcludeaboutinthisregion?（）

A:itmustbenegativenotenoughinformationgiventodecideB:itmustbezeroC:ItmustbepositiveD:itmustbezero

答案:itmustbezeroRankthefollowingstatesofaparticleinacubicalboxofsideLinorderfromhighesttolowestenergy:

(i)(nX,nY,nZ)=(2,3,2);(ii)(nX,nY,nZ)=(4,1,1);(iii)(nX,nY,nZ)=(2,2,3);(iv)(nX,nY,nZ)=(1,3,3).Theansweris:(iv),(ii),(i)and(iii)(tie).（）

A:对B:错

答案:对Rankthefollowingstatesofthehydrogenatominorderfromhighesttolowestprobabilityoffindingtheelectroninthevicinityofr=5a(i)n=1,l=0,ml=0;(ii)n=2,l=1,ml=+1;(iii)n=2,l=1,ml=0.（）

A:(ii),(iii),(i)B:(i),(iii),(ii)C:(ii)and(iii)(tie),(i)D:(iii),(ii),(i)

答案:(ii)and(iii)(tie),(i)Inthissectionweassumedthatthemagneticfieldpointsinthepositivez-component.Theresultswouldbedifferentifthemagneticfieldpointedinthepositivex-direction.（）

A:错B:对

答案:错Inwhichofthefollowingsituationsisthemagneticmomentofanelectronperfectlyalignedwithamagneticfieldthatpointsinthepositivez-direction?（）

A:neitherAorBB:bothAandBC:ms=+1/2D:ms=-1/2

答案:neitherAorB

第六章单元测试

Ifelectronsobeyedtheexclusionprinciplebutdidnothavespin,howmanyelectronscouldparticipateinacovalentbond?（）

A:oneB:twoC:morethanthreeD:three

答案:oneArotatingdiatomicmoleculeemitsaphotonwhenitmakesatransitionfromlevelltol-1levelIfthevalueoflincreases,doesthewavelengthoftheemittedphoton()?（）

A:increaseB:decreaseC:remainunchanged

答案:decreaseIfaisthedistanceinanNaClcrystalfromanNa+iontooneofitsnearest-neighborCl-ions,whatisthe

distancefromanNa+iontooneofitsnext-to-nearest-neighborCl-ions?（）

A:B:C:noneoftheseD:2a

答案:Onetypeofthermometerworksbymeasuringthetemperature-dependentelectricalresistivityofasample.Whichofthefollowingtypesofmaterialdisplaysthegreatestchangeinresistivityforagiventemperaturechange?（）

A:semiconductorB:resistorC:insulator

答案:semiconductorAnidealgasobeystherelationshippV=nRT.Thatis,foragivenvolumeVandanumberofmolesn,asthetemperatureTdecreases,thepressurepdecreasesproportionatelyandtendstozeroasTapproachesabsolutezero.Thisisalsotrueofthefree-electrongasinasolidmetal.（）

A:对B:错

答案:错

第七章单元测试

Bywhatfactormustthemassnumberofanucleusincreasetodoubleitsvolume?（）

A:4B:2C:D:8

答案:4Rankthefollowingnucleiinorderfromlargesttosmallestvalueofthebindingenergypernucleon.Theansweris:(ii),(iii),(v),(iv),(i)（）

A:错B:对

答案:错AnucleuswithatomicnumberZandneutronnumberNundergoestwodecayprocesses.TheresultisanucleuswithatomicnumberZ-3andneutronnumberN-1.Whichdecayprocessesmayhavetakenplace?()?（）

A:andecayandadecayB:TwodecaysC:andecayandadecayD:TwodecaysE:Twodecays

答案:andecayandadecayWhichsamplecontainsagreaternumberofnuclei:asampleof(half-life6560y)orasampleof(half-life7370y)?（）

A:thesampleB:thesampleC:bothhavethesamenumberofnuclei

答案:bothhavethesamenumberofnucleiAlphaparticleshave20timestherelativebiologicaleffectivenessof200-keVxrays.Whichwouldbebettertousetoradiatetissuedeepinsidethebody?（）

A:bothareequallyeffectiveB:abeamofalphaparticlesC:abeamof200-keVxrays

答案:abeamof200-keVxrays

第八章单元测试

Eachofthefollowingparticlescanbeexchangedbetweentwoprotons,twoneutrons,oraneutronandaprotonaspartofthenuclearforce.Ranktheparticlesinorderoftherangeoftheinteractionthattheymediate,fromlargesttosmallestrange.(i)the(pi-plus)mesonofmass(ii)the(rho-plus)mesonofmass(iii)the(eta-zero)mesonofmass(iv)the(omega