Question

A spherical mirror and thin spherical lens have each of focal length of +25 cm. The mirror and the likely to be

Answer 1

convex mirror and lens

Answer 2

Since the mirror and lens are spherical, these may be concave or convex.

As the focal length is positive +25 for both lens as well as mirror, so both of these are convex, i.e. the mirror is likely to be convex mirror and lens is likely to be convex lens.

This is because convex lens or convex mirror has always positive focal length.