医学物理历年试题2002_03

1MedicalCollegeofShantouUniversityTheTestPaperofMedicalPhysicsfor2002ImagingClass(A)Names:___________;RegistrationNo:____________;TotalScore:_________A.Multiplechoiceproblems(3marksforeachcorrectanswer)1.Fourphysicalquantities,length,mass,timeandtemperaturearefrequentlyusedinphysics.ThestandardunitsusedinphysicsarecalledInternationalSystemofUnits(SI).Thecorrectunitsusedforlength,mass,timeandtemperatureinSIare_____respectively.(a)meter,gram,secondandKelvin,(b)meter,kilogram,secondandKelvin,(c)meter,kilogram,hourandMole,(d)meter,gram,secondandcondela.2.Ifaspaceshipmoveswithaspeedof0.8c(cislightspeed)andinaverystronggravitationalfield,thetheoriesof_______shouldbeusedtodescribethephenomenathatoccurinthespaceship.(a)Newtonslawsandspecialrelativity(b)quantummechanicsandspecialrelativity(c)generalrelativityandquantummechanics(d)specialrelativityandgeneralrelativity3.Whentheidealfluidflowssteadilyinahorizontalpipe,therelationsofthecross-sectionSofthepipe,thevelocityvofthefluidandthepressurepofthefluidisthat______.(a)BigScorrespondstosmallvandbigp(b)BigScorrespondstobigvandsmallp(c)SmallScorrespondstobigvandbigp(d)SmallScorrespondstosmallvandbigp4.AparticlemovesintwoSHMsthathavethesamevibrationaldirectionandsamefrequency.TheequationsofthetwoSHMsaregivenbycmtscmtscos10,cos321Theamplitudeoftheadditional(superposition)vibrationis_____.(a)3cm(b)13cm(c)7cm(d)10cm5.Whichoneofthefollowingisanabsoluteblackbody?Answer:______(a)Thebodythatdoesnotradiatevisiblelight.(b)Thebodythatdoesnotradiateanyelectromagneticwaves.(c)Thebodythatdoesnotreflectvisiblelight.(d)Thebodythatdoesnotreflectanyelectromagneticwaves.6.Lightisakindofelectromagneticwavesandithasthewavepropertyofinterference.Iftwobeamsoflightinterfereataparticularpointinthespace,whatconditionsshouldthetwolightshaveatthemeetingpoint?Answer:_____(a)Samefrequency,samepropagatingdirection.2(b)Samefrequency,samedirectionandthesameinitialphase.(c)Samefrequency,samevibrationaldirectionandaconstantphasedifference.(d)Samefrequencyandthesameinitialphase.7.Ifanobjectislocated12cminfrontofalenswithfocallength10cm,thenyoucanhave______.(a)anupside-down(倒立的),reduced(缩小的)realimage(b)anupside-down,magnified(放大的)realimage(c)anupright,magnifiedvirtualimage(d)anupright,reducedvirtualimage8.Ifonemotorproduces20dbnoises,whatisthesoundintensitylevelproducedby10motorsatthesametime.Answer:______.(a)30db(b)200db(c)15db(d)40db9.Ifthemagnitudeofawavefunction,whichisasolutionofSchrödingerequation,isdoubledateverypointinthespace,thenthedistributionalprobabilityoftheparticleinthespacewill______.(a)increasetwice(b)decreasetwice(c)increasefourtimes(d)beunchanged10.Thehardnessofx-raysdependsonlyonthe____ofx-rayphoton.(a)intensity(b)speed(c)number(d)energy11.Laserisveryusefulinmedicalscience.Giveyourbestchoicefortheproductionoflaser.Answer_____.(a)Youneedtomaketheabsorption,spontaneousemissionandstimulatedemission.(b)Youneedtomakethepopulationinversionandthespontaneousemission.(c)Youneedtomakethespontaneousemissionandstimulatedemission.(d)Youneedtomakethepopulationinversionandstimulatedemission.12.Therearetwokindsofnuclides(核素).Oneisstableandtheotherisradioactive.Theradioactivenuclidesarenotstablenucleiandtheywilldecay.Therearethreeclassesofdecays.Oneofthemisdecaythatalsohasthreeforms.AstudentwritesthethreeequationstodescribethethreetypesofdecaysasPleasegiveyourequationstodescribethethreekindsofdecays.13.TwoStyrofoam(泡沫聚苯乙烯)spheresofradiiR1andR2,R1R2,arereleasedcaptureelectrondecayQdecayQAZAZAZAZAZAZQYXYXYX1-1-13simultaneouslyfromtheroofofa60mhighbuilding.(a)Sphere2willarriveatthegroundfirst.(b)Sphere1willarriveatthegroundfirst(c)BothSphereswillreachthegroundatthesamemoment.(d)Theanswerdependsonthelocalatmosphericpressure.14.Alensmadefromglasswitharefractiveindexof3/2isputinwaterthathasarefractiveindexof4/3.Thefocallengthoftheopticalsystemis______ifthelenshastwoconvexsurfaceswithradiiofcurvature0.1mand0.2mrespectively.(a)15/8,(b)15/2;(c)8/15;(d)2/15;(e)noneoftheabove.B.Fillinginthefollowingblankswithyourcalculatingresults(3marksforeachblankinquestions1,2and3;1markforeachblankinquestion3):1.Amyopicpersonhasafarpointof0.5mandanearpointof0.1m.Inordertocorrectthemyopia,thepowerofthelensshouldbe_-2D（__-200度）_______;whenthepersonwearsthecorrectivelenses,thenewnearpointis_0.125m________.2.Williamblowsasoapbubblewithdiameterof8cm.Supposethatitssurfacetensioncoefficientis4010-3Nm-1.Theworkdonebyblowingthesoapbubbleis_____andtheadditionalpressureinthebubbleis__2Pa______.3.Inaninterferencepatternfromtwoslits,thetenth-orderbrightfringeis40.0mmfromthezeroth-orderbrightfringe.Thedoubleslitis5metersawayfromthescreen,andthetwoslitsare0.5mmapart.Thewavelengthofthelightis___0.04mm____andthespacingofthefifthandsixthbrightfringesis____4mm________.4.Therearetwocoherentwavesourcespropagatinginthesamemediumandinthesamex-positivedirection.Theirmotioncanbedescribedbytheequations)(332cos03.0)(32cos05.021mxtSmxtSObviously,thesetwowaveswillinterferenceat