A double convex lens of focal length 20 cm is made of glass of refractive index 3 / 2. When
Channel: Doubtnut
Date: 23/08/2020

A double convex lens of focal length 20 cm is made of glass of refractive index 3 / 2. When placed completely in water `(._(a)mu_(w)=4//3)`,  its focal length will be