Question

A ray PQ incident on the refracting face BA is refracted in the prism BA C as shown in the figure and emerges from the other refracting face AC as RS, such that AQ = AR. If the angle of prism $A = 60^\circ$ and the refractive index of the material of prism is $\sqrt 3,$ then the angle of deviation of the ray is

• A. $60^\circ$
• B. $45^\circ$
• C. $30^\circ$
• D. None of these

Answer 1

Answer: (A)

$60^\circ$

Answer 2

For a given prism, the angle of deviation depends upon the angle of incidence of the light rays falling on the prism.
Taking triangle FQR, we have

$S = \angle FQR + \angle FRQ$