Question

The refractive indices of four media A, B, C and D are 1.44, 1.52, 1.65 and 1.36 respectively. When light travelling in air is incident in these media at equal angles, the angle of refraction will be the minimum:

(a) in medium A
(b) in medium B
(c) in medium C
(d) in medium D

Answer 1

(c) in medium C

​Refractive index = $\frac{\sin \mathrm{i}}{\sin \mathrm{r}}$

The angle of incidence is equal in all the cases; therefore, the refractive index will be maximum in the case of minimum angle of refraction. According to this argument, medium C will have minimum angle of refraction because it has maximum refractive index.