Q 12-09-228JEE MainJEE Main 2025 (2 Apr, Shift 2)Easy
A ray of light suffers minimum deviation when incident on a prism having angle of the prism equal to $60^\circ$. The refractive index of the prism material is $\sqrt2$. The angle of incidence (in degrees) is ______.
Numerical value type. Enter your answer.
Answer: 45
At minimum deviation the ray passes symmetrically, so $r = A/2 = 30^\circ$.
Snell's law at the first face:
$$\sin i = \mu\sin r = \sqrt2\times\frac12 = \frac{1}{\sqrt2} \Rightarrow i = 45^\circ$$
Solution by Sreeraj P, M.Sc Physics