In a plano-convex lens the radius of curvature of the convex lens is $10\ cm$. If the plane side is polished, then the focal length will be (Refractive index = 1.5)

Question

Dr. Abubacker · Accepted Answer

(b) $f = \frac{R}{\mu - 1} = \frac{10}{(1.5 - 1)} = 20\ cm$
$\frac{1}{f} = \frac{2}{f_{1}} + \frac{1}{f_{m}},f_{m} = \infty \Rightarrow f = \frac{f_{1}}{2} = \frac{20}{2} = 10\ cm$

Q. In a plano-convex lens the radius of curvature of the convex lens is $10\ cm$. If the plane side is polished, then the focal length will be (Refractive index = 1.5)

Explanation

Reviewed by Dr. Abubacker

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