question_answer

A prism of refractive index \[\sqrt{2}\] has a refracting angle of 60o.  At what angle a ray must be incident on it so that it suffers a minimum deviation             [BHU 2003; MP PMT 2005]

A)            45o

B)            60o

C)            90o

D)            180o

Correct Answer: A

Solution :

           \[\mu =\frac{\sin i}{\sin \frac{A}{2}}\]\[\Rightarrow \sqrt{2}=\frac{\sin i}{\sin \left( \frac{60}{2} \right)}\]