Question

A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices μ1 and μ2 and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is -

Answer 1

The answer to the question: A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other.

If lenses are made of different materials of refractive indices μ1 and μ2 and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is : R/( μ1- μ2).