Thick Lenses

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University of KwaZulu-Natal- Westville Campus**We aren't endorsed by this school

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BIO OPTM141

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Mechanical Engineering

Date

Jan 6, 2025

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Uploaded by BailiffPower5724

Thick Lensesand MultipleLens Systems147SupplementalProblemsNeutralizing,BackVertex,andEquivalentPowers;FocalLength,Thickness7-1.Athick plastic lens (n=1.49)hasafront surfacepower of+2.00Dandabacksurfacepower of-7.00D.Iftheequivalentpoweris-4.50D,whatisthe thicknessofthe lens?ANS.5.32cm7-2.Whatisthebackvertexpower (Fv)ofa lenssystemconsistingoftwothin lensesofpowers+8.00Dand-1.00D,separatedby4cm?ANS.+10.76D7-3.Whatisthe equivalentpower ofa glass lens (n=1.5)thathasafront surfacepowerof+10.00Dandabacksurfacepowerof-5.00Dandis6mmthick?ANS.+5.20D7-4.Thebackfocal length of a lensunderwateris-40.00cm.Whatisthebackvertexpowerofthe lensunderwater?ANS.-3.33DPrincipalPlanes,NodalPoints,FocalPoints7-5.Athickbiconvexlens with front radiusof8cmandabackradiusof4.31cmhasabacksurfacepower of+13.00Dandabackvertexpowerof+25.70 D.GiventhatHH'=+0.90cm,calculate the following(Answersin parentheses):a.Theindexofrefractionofthelens(n=1.56)b.Thepowerofthe front surface(F=+7.00D)c.Thethicknessofhelens(t=10cm)d.Theneutralizingpower (Fn) (Fn=+85.00D)e.Thetotalpowerofthe lens(F=+14.17D)f.Theprimary andsecondaryfocal lengths(f=-7.06cm,f=+7.06cm)8.Thefrontand backfocallengths(fl -1.18cm,bfl=+3.89cm)h. Locatethefirst principalplanerelativetothefront surface(AjH=+5.88cm)i.Locate thesecondprincipalplanerelative tothefront surface(AjH=+6.83 cm)j.Locatethenodalpoints (thenodalpointscoincidewiththe principalplanes)7-6.Athick lenssystemin airhasabackvertexpower of+10.91D,a neutralizingpowerof+4.47Dandasecondaryfocal length of+19.72cm. Thelensis5cmthickandhasanindexof1.50. Calculate the following(answersin parentheses):a.Thefrontandbackfocallengths(fl=-22.37cm;bfl=+9.17cm)b.Theequivalentpower(F=+5.07D)c.Locatethefirstprincipalplanerelative tothefront surface(AjH=-2.65cm)d. Locatethesecondprincipalplancrelative tothebacksurface(AgH=-10.56cm)e. Locatethenodalpoints(N=-2.65cmfromAj:N'=-10.56cmfromAg)7-7.Alenssystemhasabackvertexpowerof+5.00D,a neutralizingpowerof+4.00D,andan equivalentppowerof+10.00D. Thebacksurfaceisinwater,andthe front surfaceisinair.Findthe following(answersinparentheses):a.Thefirstprincipalplanerelative to the frontsurface(AjH=-15cm)b.Thesecond nodalpointlocatedrelative tothebacksurface(HN=+3.3cm)c.Thesecondaryfocal lengthofthesystem(f=+13.3cm)

148TheGeometrical OpticsWorkbookImage-ObjectRelationships, Magnification7-8.Ifareal objectwereplaced 94.1cmin front of the lens (to theleft) inProblem7-5,wherewouldtheimagebeformedrelativeto thebacksurface?ANS.+10.76cmfromthebacksurface7-9.Locatetheobject positionifan imageisformed4.44cmbehindthe lensinProblem7-3.ANS.Theobjectis62.6cmbehindtheprincipalplane7-10.Usethe element-by-elementmethodtodeterminetheimagelocation for the followingthick lenssystem:the front surfacepoweris+10.00D,thebacksurfacepoweris+5.00D,the index of refractionandthe thicknessofthe lens are 1.50and5cm,respectively,andtheobjectisplaced50cmfromthe front surface.ANS.The imageisformed 6.28cmbehindthebacksurface7-11.Areal objectisplaced40cmfromthefirstprincipal planeofalenssystem.If thebackvertexpoweris+2.00D,the neutralizingpoweris+3.0D,andthe equivalentpoweris+6.00D,whereistheimagelocated relativetothesecondprincipal plane?ANS,+29cm