A ray of light XY passes through a right angled isosceles prism as shown below

A ray of light XY passes through a right angled isosceles prism as shown below.

1. What is the angle through which the incident ray deviates and emerges out of the prism?
2. Name the instrument where this action of prism is put into use.
3. Which prism surface will behave as a mirror?

Answer

1. 900
2. refracting periscope
3. Surface AB