An equi convex thin lens of glass u has focal length in air

Last updated: 6/8/2023

An equi convex thin lens of glass u has focal length in air as 20 cm Now one of its convex face is silvered to make equivalent mirror In case i this equivalent mirror is kept in air and in case ii it is kept in water u Then O Radius of curvature of convex side of lens is 10 cm Focal length of equivalent mirror in both case is same Focal length in case i is 6 cm Focal length in case ii is 8 cm