There  is an equiconvex glass lens with radius of each face as R and `._(a)mu_(g) = 3//2`
Channel: Doubtnut
Date: 30/08/2020

There  is an equiconvex glass lens with radius of each face as R and `._(a)mu_(g) = 3//2` and `._(a)mu_(W) = 4//3` . If there is water in object space and air in image space, then the focal length is