question_answer

A given ray of light suffers minimum deviation in an equilateral prism P. Additional prism Q and R of identical shape and of the same material as Pare now added as shown in the figure. The ray will now suffer

A)  greater deviation                         

B)  no deviation

C)  same deviation as before                 

D)  total internal reflection

Correct Answer: C

Solution :

 No deviation occur on interfaces 2 and 3 as there is no change in medium. However, deviation at interface 4 is same as it was on interface 2 with only prism p.