A rectengular glass slab ABCD of refractive index n_1 is immersed in water of refractive index `
Channel: Doubtnut
Date: 2020-07-12

A rectengular glass slab ABCD of refractive index n_1 is immersed in water of refractive index `n_2(n_1gtn_2)`. A ray of light is incident at the surface AB of the slab as shown. The maximum value of the angle of incidence `alpha_max` such that the ray comes out only from the other surface CD is given by