Question

If a concave mirror of focal length 10 cm is immersed in water its focal length will

Answer 1

remain same.This is because the focal length of mirrors does not depend on the external medium in which it  is held. In case of lenses, refraction takes place whena lens is immersed in water , the value of refractive index decreases. Hence it's focal length inc.

Answer 2

If a concave mirror of focal length 10 cm is immersed in water its focal length will remain the same.

• A concave mirror is a type of spherical mirror in which the reflecting surface has an inward curve.
• It is also called a converging mirror as it converges parallel rays of light at a single point.
• The focal length of mirrors (concave or convex) depends only on the curvature of the mirror.
• The focal length is independent of the medium of the surroundings.
• For a lens, however, the focal length depends on the surrounding medium.