What is the length of the image of the rod in mirror, according to the observer in air? (refractive index of the liquid is `mu`)

What will be the change in focal length f of a concave mirror when immersed in a liquid of refractive index n?

What will be the change in focal length f of a concave mirror when immerged in a liquid of refractive index n?

An equiconvex lens mu =(3)/(2) is placed over a plane mirror as indicated in diagram. An object placed "12cm" from system such that image and object coincide.Now a liquid is poured between mirror and lens and for the same object the image now formed at "24cm" from mirror.The refractive index of the liquid poured will be

The radii of curvature of two spherical surfaces of a concave convex lens (mu=1.5) are 20 cm and 40 cm. (i) What is its focal length when it is in air? Also find its focal length when it is immersed in a liquid of refractive index (ii) mu=1.2 (iii) mu=2