Question

a ray of light is incident normally one of the refrective surface of a prism. the angle of prism is 30.find the angle of deviation for the ray of light . given refrective index is 2

Answer 1

Since the ray was incident normally on the surface, angle of incidence is 0, angle of refraction is 0, and also the angle of deviation is 0

Answer 2

A = 30°
μ = √2
(For thin prisms) We have the relation δ = (μ − 1)A
                                 = (√2 − 1) x 30°
                                 = 12.4°

The option which is close to this is (D).