Q 12-09-069JEE MainJEE Main 2025 (23 Jan, Shift 2)Easy
The refractive index of the material of a glass prism is $\sqrt3$. The angle of minimum deviation is equal to the angle of the prism. What is the angle of the prism?
Answer: (A) $60^\circ$
With $\delta_m = A$:
$$\mu = \frac{\sin\left(\frac{A+\delta_m}{2}\right)}{\sin\frac{A}{2}} = \frac{\sin A}{\sin\frac{A}{2}} = 2\cos\frac{A}{2}$$
$$2\cos\frac{A}{2} = \sqrt3 \Rightarrow \frac{A}{2} = 30^\circ \Rightarrow A = 60^\circ$$
Solution by Sreeraj P, M.Sc Physics