A prism of refractive index 2 has a refracting angle of 60^ . At what angle a ray must be incident on it so that it suffers a minimum deviation.

Step-by-step solution

The relation for refractive index of prism is = i r (1) The condition for minimum deviation is r= A 2 = 60^ 2 =30^ Putting the given value of = 2 and r=30^ in eq (1), we get aligned 2 & = i 30^ So, i & = 2 1 2 = 1 2 i & = 45^ i & =45^ aligned