A concave mirror of focal length `f` in vacuum is placed in a medium of refractive index 2. its focal length in the medium is

Assertion : The radius of curvature of a mirror is double of the focal length. Reason : A concave mirror of focal length f in air is used in a medium of refractive index 2. Then the focal length of mirror in medium becomes 2f.

Assertion : A concave mirror of focal length f in air is used in a medium of refractive index 2. Then the focal length of mirror in medium becomes double. Reason: The radius of curvature of a mirror is double of the focal length.

A thin lens of refractive index 1.5 has focal length of 15 cm in air. When the lens is placed is a medium of refractive index (4)/(3), its focal length will become …..cm.

A lens of refractive index mu becomes a lens of focal length f' when immersed in a liquid of refractive index mu '. If the focal length of the lens in air is f, prove that f' = f.(mu'(mu-1))/((mu-mu')) .

A concave mirror has a local length of 2m in vacuum. What would be its focal length when used in a medium of refractive index 2.759 ?

A concave mirror of focal length f (in air) is immersed in water (mu=4//3) . The focal length of the mirror in water will be