$A$ ray of light travels from an optically denser medium to a rarer medium. The critical angle for the two media is $C$. The maximum possible deviation of the refracted light ray can be:

What should be the maximum acceptance angle at the air-core interface of an optical fibre if $n_1$ and $n_2$ are the refractive indices of the core and the cladding respectively?

$A$ rectangular glass slab $ABCD$,of refractive index $n_1$,is immersed in water of refractive index $n_2$ $(n_1 > n_2)$. $A$ ray of light is incident at the surface $AB$ of the slab as shown. The maximum value of the angle of incidence $\alpha_{max}$,such that the ray comes out only from the other surface $CD$,is given by

Write the definition of critical angle.

For total internal reflection to take place,the angle of incidence $i$ and the refractive index $\mu$ of the medium must satisfy the inequality

Explain the experiment which demonstrates total internal reflection.