Question

With the help of a neat ray diagram explain the phenomenon of total internal refraction and critical angle.

Answer 1

Total internal reflection happens when a ray of light strikes a medium boundary at an angle greater than a particular critical angle. There are two important condition for TIR to occur. First, the angle of incidence of the light ray must exceed the critical angle at the interface. Second, ray must travels from denser to rarer medium. The angle of incidence above which the total internal occurs is called critical angle.