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 16-4-2018]

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

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

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

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

Correct Answer: B

Solution :

 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.