Question

A spherical mirror and a thin spherical lens have each a focal length of -20cm .The mirror and the lens are likely to be:​

Answer 1

Answer:

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.