自然科学实验物理生物化学模板下载

OpticalInstrumentMindMappingOpticalInstrumentalMicroscopeTheEyeTheMagnifyingGlassCameraTelescopeDefectsinHumanEye:-Myopia(nearshightedness)-Hypermetropia(Farsightedness)-Astigmatism-PresbyopiaFunction:tomagnifyasmallobjectortomagnifythefinedetailsofalargerobjectinordertoexamineminutespecimensthatcannotbeseenbythenakedeye.Function:toseeabiggerpictureoftheobjectbeingobserved.Function:torecordanimageofanobject,eitheronphotopaperordigitally.Function:forobservationofremoteobjectsbycollectingelectromagneticradiation,suchasvisiblelight.TableofContent01TheEye02TheMagnifyingGlass03TheCamera04TheMicroscope05TheTelescopeWhatis

OpticalInstrument?Opticalinstrumentsarethedeviceswhichprocesslightwavetoenhanceanimageformoreclearview.Useofanopticalinstruments,suchasamagnifyinglensoranycomplicateddevicelikemicroscopeortelescopeusuallymakesthingsbiggerandhelpsustoseeinamoredetailedmanner.Theuseofconverginglensesmakesthingsappearlargerandontheotherhand,diverginglensesalwaysgetsyousmallerimages.TheEyeThehumaneyeis,whichisthemostperfectopticalinstrument,canseeobjectsanddistinguishcolorswhitinaverybroadrange.Theeyeisshapedlikeaspherewitha2.5cmradius,andthecorneaislocatedatthefrontofitsexternalsurface,calledthescleraandactsasawindow.PowerofEyeAccommodationPowerofaccommodationistheprocessbywhichciliarymusclesfunction,toadjustthefocallengthoftheeyessothatclearimageformsontheretina.Thisvariesfarornearbyobjects.Here,Eyelensisthick.So,ithassmallfocallengthandmoreconvergingpowerHere,Eyelensisthin.So,ithaslargefocallengthandsmallconvergingpowerDefectsinHumanEyeMyopia(nearshightedness)Nearsightedness,ormyopiaisavisiondefectthatoccurswhenthefocusoftheimageisinfrontoftheretina.Thisisshownin.Closeobjectsareseenfine,butdistantobjectsareblurry.01Hypermetropia(Farsightedness)Farsightedness,orhyperopia,isavisiondefectthatoccurswhenthefocusoftheimageisbehindtheretina.Thisisshownin.Distantobjectsareseenfine,butcloserobjectsareblurry.02AstigmatismAstigmatismisadefectwhereinthelightraysenteringtheeyedonotfocuslightevenlytoasinglefocalpointontheretinabutinsteadscatteraway.Thelightraysinawaywheresomefocusontheretinaandsomefocusinfrontoforbehindit.03PresbyopiaPresbyopiaisanaturaldefectthatoccurswiththeage.Inpresbyopia,theciliarymusclesbecomeweakandarenolongerabletoadjusttheeyelens.Theeyemusclesbecomesoweakthatnolongercanapersonseenearbyobjectsclearly.Thenearpointofapersonwithpresbyopiaismorethan25cm.04Myopia(Nearshighted)EyetooLongorCorneatooSharplyCurvedRaysFocusinFrontofTheRetinaHypermetropia(Farsightedness)EyetooShortorCorneanotCurvedEnoughtRaysFocusBehindTheRetinaAstigmatismLightFocalPointAstigmaticcorneadistortsthefocalpointoflightinfrontofand/orbehindtheretinaRetinaAstigmaticCorneaPresbyopiaLessFlexibleLensFocalPointThelensagesandstiffens,bringingthefocalpointbehindtheretinaandcausingblurryvisionLightRetinaOpticalIllusionWhichoneisbigger?Whichoneislonger?TheMagnifyingGlassWhatisMagnifyingGlassThemagnificationofamagnifyingglassdependsuponwheretheinstrumentisplacedbetweentheuser’seyeandtheobjectbeingviewedanduponthetotaldistancebetweeneyeandobject.Themagnifyingpoweristheratioofthesizesoftheimagesformedontheuser’sretinawithandwithoutthemagnifyingglass.Whennotusingthelens,theuserwouldtypicallybringtheobjectasclosetotheeyeaspossiblewithoutitbecomingblurry.FormulaofMagnificationS=Snfhh’OS’=SnFormulaofmagnification:sm=s’fm=25+1Formulaoflens:sf=1+s’1

f=20cmh’?h=0,2cmOSampleQuestionAloopfocusing20cmisusedtoobserveobjectsthatarethelengthis2mm.Determinethelengthoftheobject'sshadowiftheeyeismaximumaccommodation?Answer:fm=25+120m=25+1=2,25timeshm=h’h’=mxhh’=2,25x0,2h’=0,45cmTheCameraAcameraisanopticalinstrumentusedtorecordimages.Thewordcameracomesfromcameraobscura,whichmeans"darkchamber"andistheLatinnameoftheoriginaldeviceforprojectinganimageofexternalrealityontoaflatsurface.Themodernphotographiccameraevolvedfromthecameraobscura.Thefunctioningofthecameraisverysimilartothefunctioningofthehumaneye.Thefirstpermanentphotographwasmadein1825byJosephNicéphoreNiépce.PartsofaCameraFilmLightrayLensMirrorViewfinderPrismTheMicroscopeAmicroscopeisaninstrumentusedtoseeobjectsthataretoosmalltobeseenbythenakedeye.Microscopyisthescienceofinvestigatingsmallobjectsandstructuresusingsuchaninstrument.Microscopicmeansinvisibletotheeyeunlessaidedbyamicroscope.PartsofaMicroscopeEyepiecelensIlluminatorFinefocusCoarsefocusArmTubeObjectivelensBaseStagewithclipsFormulaofMicroscopeOcularlensObjectivelensfocfobjfobjsobjsobjfocsocsocThelengthofthemicroscope(tube)canbestated:l=s’obj+focMagnificationofobjective:fm=snsobjm=s’objxfoc25Magnificationformula:m=mobjxmocFormulaofMicroscopeOcularlensObjectivelensfocfobjfobjsobjsobjfocsocsocMagnificationofeye-piece:fm=sn+1sobjm=s’objfoc25+1Thelengthofthemicroscope(tube)canbestated:l=s’obj+socMagnificationformula:m=mobjxmocSampleQuestionOcularlensObjectivelensfocfobjfobjsobjsobjfocsocsocThetotalmagnificationofamicroscopeis200x,ifmagnifiedformedobjectivelens10x,howmuchthemagnificationofthelenstheocular?Answer:m=mobjxmocmoc=10200=20timesTheTelescopeTelescopesaremeantforviewingdistantobjects,producinganimagethatislargerthantheimagethatcanbeseenwiththeunaidedeye.Telescopesgatherfarmorelightthantheeye,allowingdimobjectstobeobservedwithgreatermagnificationandbetterresolution.PartsofaTelescopeEyepiecelensObjectivelensMaintubeFocused