question_answer

A ray of light is incident at an angle of \[{{60}^{o}}\]on one face of a prism of angle\[{{30}^{o}}.\]The emergent ray of light makes an angle of with incident ray. The angle made by the emergent ray with second face of prism will be: [JEE Main Online 16-4-2018]

A) \[{{30}^{o}}\]

B) \[{{90}^{o}}\]

C) \[{{0}^{o}}\]

D) \[{{45}^{o}}\]

Correct Answer: B

Solution :

[b] Here

\[{{i}_{1}}=60\]

\[A=30\]

\[\delta =30\]

Since, \[\delta ={{i}_{1}}+{{i}_{2}}-A\]

\[{{i}_{2}}=0\]

So from the surface, it will make.