question_answer

A ray of light falls on the surface of a spherical paper weight making an angle a with the normal and is refracted in the medium at an angle P. The angle of deviation of the emergent ray from the direction of the incident ray is -

A) \[\left( \alpha -\beta  \right)\]                    

B) \[2\text{ }(\alpha -\beta )\]

C) \[\left( \alpha -\beta  \right)/2\]                 

D) \[\left( \beta -\alpha  \right)\]

Correct Answer: B

Solution :

\[\delta =2(\alpha -\beta )\]