A monochromatic light wave is incident normally on a glass slab of thickness d, as shown in the figure. The refractive index of the slab increases linearly from n₁ to n₂ over the height h. Which of the following statement(s) is (are) true about the light wave emerging out of the slab ?

Question

G1 Physics · Accepted Answer

For a weak vertical refractive-index gradient, the ray acquires a transverse angular change proportional to the gradient dn/dy=(n₂-n₁)/h over thickness d. Thus the deflection is tan⁻¹[((n₂-n₁)d)/h], which depends only on n₂-n₁. Hence B and D are correct.