Question

A concave mirror is kept in water. Wil There be an change in focal length
compared to that in air? Justify.

Answer 1

Answer:

No there would be no change in the focal length.

Because the focal length of a mirror depends on the lens and not tge medium in which it travels.

Light will still travel in straight lines

thus forming the same patterns as in air. And hence giving conclusive evidence of the focal length being the same.

Answer 2

The focal length of the concave mirror does not change when it is immersed in water because focal length of a mirror does not depend upon the refractive index of the medium. Therefore, when a convex lens is dipped into water, its focal length increases.