Write a short notes on the prisms making use of total internal reflection.

Explanation

Prism can be designed to reflect light by `90^(@)` or by `180^(@)` by making use of total internal reflection. The critical angle `i_(c)` for the material of the prism must be less than `45^(@)`. This is true for both crown glass and flint glass. Prisms are also used to invert images without changing their size.