Question

What are required conditions for TIR ?

Optics ,Class -12

Answer 1

For Total internal reflection to occur ,

1) The ray of light must pass from optically denser medium to optically rarer medium .

2) The angle of incidence must be greater than critical angle .

hope helped !

Answer 2

The only way for the angle ofrefraction to be greater than the angle of incidence is for light to bend away from the normal. Since light only bends away from the normal when passing from a more dense medium into a less dense medium, then this would be a necessary condition for total internal reflection.