Question

A parallel glass slab, of thickness 4 cm, has been made from a glass of refractive index √3 . A ray of light is incident on one face at an angle of incidence of 60°. The lateral shift of the ray, due to refraction, through the slab, is (nearly)

(1) 2.0 cm

(2) 2.3 cm

(3) 2.6 cm

(4) 2.9 cm

Answer 1

(2) 2.3 cm

Fig. shows incident ray PQ undergoing refraction through glass slab. RS is the emergent ray. The lateral displacement = RT = x (say).

From right angled ΔQRT

Applying Snell’s law at point Q,

Given t = 4 cm. From Eqn. (1) we have