QJEEM19Ph814b: JEE Main 2019 Physics - Class 12 JEEM19Ph814b Solution: A plano-convex lens (focal length f 2 , refractive index μ 2 ,…

Question

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A plano-convex lens (focal length f₂, refractive index

μ

₂, radius of curvature R) fits exactly into a plano-concave lens (focal length f₁, refractive index

μ

₁, radius of curvature R). Their plane surfaces are parallel to each other. Then, the focal length of the combination will be :

Accepted Answer

\frac{1}{F} = \frac{1}{f_{1}} + \frac{1}{f_{2}} = \frac{1 - μ_{1}}{R} + \frac{μ_{2} - 1}{R}

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