医学物理历年试题TestPaper04A

1MedicalCollegeofShantouUniversityTheTestPaperofMedicalPhysicsfor2004studentsunder7-yearteachingsystem(A)Names:___________;RegistrationNo:____________;ProblemtypesABCDETotalScoreScoreobtainedMarkers’signatureA.Answerthefollowingquestions(2marksforeachquestion;totalscore10)1.Whatarethecoherent（相干的）conditionsfortwomechanicalwaves?2.)cos(tAxistheequationofsimpleharmonicmotion.Isthevelocityofasimpleharmonicoscillator(振动器)everzero?Ifso,where?3.Therearethreekindsofstrainstodescribetheshapechangeofanobjectunderdifferentstresses(forces).Whatarethey?4.Surfacetensioncoefficienthastwomeanings.Giveyouexplanationsbelow.Score25.InBohr’satomictheory,therearetwohypothesesonorbitalmomentumandlightemissions.Whatarethey?(hint:ifyoufeeldifficultindescribingthembywords,youcouldsimplywritetheirmathematicalequations.)B.Rightorwrong(2marksforeachquestion;totalscore20)1.Theimagedistanceisalwayspositiveiftheimageisonthesideofthelensfromwhichthelightiscoming.rightwrong2.TwosteelspheresofradiiR1andR2areputinaverydeeptankwhichcontainsviscousfluid,theonewithbiggerradiusgoesdownfasterthantheotherbecausethefluidisviscous.rightwrong3.Thehardnessofx-raysdependsonlyontheenergiesofx-rayphotons.rightwrong4.TheequationsofthetwoSHMsaregivenbycmtscmtscos5,cos321astheyareout-ofphase(反相),theamplitudeofthesuperpositionvibration(21sss)is|A1-A2|,thatis2cm.rightwrong5.Asthemoleculesofnon-surface-activeagentstendtomovetothesurfaceofliquid,itcanchangethesurfacetensioncoefficientoftheoriginalliquidgreatly.rightwrong6.ThewavelengthofthescatteredlightintheexperimentofComptoneffectsbecomeslongerbecauseitlostsomeenergyduringtheprocessoftheScore3collisionwithelectron.rightwrong7.Whenlighttravelsthroughamediumwithrefractiveindex1.5,bothwavelengthandfrequencyoflightwillchangealittlebitinordertosatisfythespeedoflightinsuchamedium.rightwrong8.Thesquaredmagnitudeofanormalizedwavefunction,2,expressestheprobabilityoffindingtheparticleinthecorrespondingregion.Therefore,ifthewavefunctionismultipliedby3,thepossibilityoffindingtheparticleinthesameregionshouldbe9timeslarger.rightwrong9.Indampedharmonicmotion,thesystemhasthefollowingpropertiesduetothedampedforceexertingonthesystem:(1)themechanicalenergyofthesystemdecreases;(2)thevibrationalamplitudedecreases;(3)theperiodofthesystemdecreasesand(4)thevibrationgoesslower.rightwrong.10.Inthesingle-slitdiffractionexperiment,thecenterofbrightfringeshastobesatisfiedwiththeconditionofmasin.Whereaisthewidthoftheslit;mtakesanyintegernumbers,isthewavelengthusedintheexperiment.rightwrongC.Multiplechoiceproblems(3marksforeachquestion,totalscore:30)(Note:NoneoftheabovemeansthatnooneofA,B,CandDiscorrectanswerforthequestion)1.Planck’sformulaforblackbodyradiationisgivenbelow:12)(/52kThcehcTMScore:4inordertogetStefanandBoltzmann’slawfromaboveformula,youneedatleast________.A.toingrateM(T)withrespectto;B.todifferentiateM(T)withrespectto;C.tomake1/kThcasitisvalidwhenwavelengthislarge;D.tomake1/kThcasitisvalidwhenwavelengthissmall;2.Whentheidealfluidflowssteadilyinahorizontalpipe,therelationsofthecross-sectionSofthepipe,thevelocityvofthefluidandthepressurepofthefluidisthat______.A.BigScorrespondstosmallvandsmallpB.BigScorrespondstobigvandbigpC.SmallScorrespondstobigvandsmallpD.SmallScorrespondstobigvandbigpE.Noneoftheabove3.Theintensityofx-raysdependsonlyonthe____ofx-rayphotons.A.hardnessB.speedC.numberD.frequencyE.noneoftheabove4.Ifanobjectislocated12cminfrontofathinlenswithfocallength10cm,thenyouwillhavea______.A.reducedrealimageB.magnified(放大的)realimageC.magnifiedvirtualimageD.reducedvirtualimageE.noneoftheabove5.Laserisveryusefulinmedicalscience.Giveyourbestchoicefortheproductionoflaser.Answer_____.A.Youneedtomaketheabsorption,spontaneousemissionandstimulatedemission.B.Youneedtomakethepopulationinversionandthespontaneousemission.C.Youneedtomakethespontaneousemissionandstimulatedemission.D.Youneedtomakethepopulationinversionandstimulatedemission.6.Amonochromaticlightofwavelength600nmfallsonadoubleslitofseparation2mm.Ifascreenisplacedatadistanceof5mfromtheslits,findthedistanceofthefirstbrightfringefromthecenterofthezerothorderbrightfringe._______A.0.3mmB.0.15cmC.0.15mmD.0.3cmE.1.5mm57.ThegraphshowstheamountofenergyEradiatedfromablackbodyatawavelengthagainstthewavelengthfordifferenttemperature.i(i=1,2,3)arethewavelengthscorrespondingtothemaximumenergyofradiationforT1,T2,andT3respectively.WhichoffollowingstatementsconcerningthegraphisTRUE?_________(1)T1T2T3(2)1T1=2T2(3)1/2=E1/E2A.(1)only,B.(2)only,C.(1)and(2),D.(1)and(3)8.WhichofthefollowingisNOTtrueconcerningtheemissionofelectronfromametalsurfacebyasuitablebeamoflight?________A.Increasingtheintensityofthebeamwillincreasethenumberofphotoelectrons.B.Onlylightofwavelengthsuchthatc(thresholdwavelength)cancausetheemissionofelectrons.C.Increasingthefrequencyoflightwillincreasethemaximumkineticenergyoftheemittedelectrons.D.Increasingtheintensityofthebeamwillincreasethevelocityoftheemittedelectrons.E.Noneoftheabove.9.Aparticlewi