Q 12-09-218JEE MainJEE Main 2018 (16 Apr, Shift 1)Medium
A ray of light is incident at an angle of $60^\circ$ on one face of a prism of angle $30^\circ$. The emergent ray of light makes an angle of $30^\circ$ with incident ray. The angle made by the emergent ray with second face of prism will be:
Answer: (B) $90^\circ$
Deviation: $\delta = i + e - A$.
$$30^\circ = 60^\circ + e - 30^\circ \quad\Rightarrow\quad e = 0^\circ$$
The emergent ray leaves along the normal to the second face, so it makes $90^\circ$ with that face.
Solution by Sreeraj P, M.Sc Physics