Question

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?

• A. It will deflect up by an angle tan⁻¹\([\frac {(n_2^2 - n_1^2)d}{2h}]\).
• B. It will deflect up by an angle tan⁻¹\([\frac {(n_2 - n_1)d}{h}]\).
• C. It will not deflect.
• D. The deflection angle depends only on (𝑛₂ − 𝑛₁) and not on the individual values of 𝑛₁ and 𝑛₂.

Answer 1

The Correct Option is D

The deflection angle indeed depends only on the difference between the refractive indices (n₂ - n₁) and is independent of the specific values of n₁ and n₂. As long as the refractive index increases linearly, the deflection angle will depend solely on the difference in refractive indices. 
Therefore, option (4) is correct.