The radius of curvature of the curved surface of a plano-convex lens is `20 cm`. If the refractive index of the material of the lens be `1.5`, it will

Options

A. act as a convex lens only for the objects that lie on its curved side
B. act as a concave lens for the objects that lie on its curved side
C. act as a convex lens irrespective of the side on which the object lies
D. act as a concave lens irrespective of side on which the object lies

Answer

3

Explanation

Hence, R=20cm, `mu` =1.5. On substituting the values, we get f = `R/(mu-1) = 20/(15-1) = 10 cm` As f gt 0 means converging nature. Therfore, lens act as a convex lens irrespective ofthe side on which the object lies