A circular beam of light of diameter d=2cm falls on a plane surface of glass. The angle of incidence is 60⁰ and refractive index of glass is $\mu =3/2$ . The diameter of the refracted beam is:

A total refractive prism is also known as a total internal reflection prism. It is an optical prism that is designed for reflecting 100% of the incident light. This happens since this prism uses the principle of total internal reflection. These prisms are oriented and shaped in a specific way so that the light that enters at a specific angle is completely reflected inside the prism. A right-angle prism, porro prism, dove prism and roof prism are some of the examples of total reflective prism. 

Total deviation in a prism is the total angle by which the light ray gets bent as it passes through the prism. It is an angle between incident ray and emergent ray of the prism. When a light enters the prism, it will bend towards the normal. After that, it will travel through the prism and bend away from the normal as it exits. Total deviation is the sum of these two from which the apex angle is subtracted.

The formula for total deviation for a prism is as follows:

$\delta = i_1 + e_2 - A$

• $i_1$ : angle of incidence at first surface
• $e_2$ : angle of emergence at second surface
• A: apex angle of the prism