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
1
act as a convex lens only for the objects that lie on its curved side.
2
act as a concave lens for the objects that lie on its curved side.
3
act as a convex lens irrespective of the side on which the object lies.
4
act as a concave lens irrespective of side on which the object lies.