Question

When wave enter from rarer to denser medium it undergoes path difference of how many???

Answer 1

The ray bends towards normal after entering denser medium from rarer medium. The quantum depends on refractive of the two mediums.

Explanation:

The ray bends towards normal after entering denser medium from rarer medium. The quantum depends on refractive of the two mediums.

If `theta_1` is the angle of incidence with the normal and `theta_2` is the angle of refraction, then

`(sintheta_1)/(sintheta_2)=n_2/n_1`

where `n_1` and `n_2` are refraction indices of the two medium.

If `n_2>n_1`, it is of course that we will have `theta_1>theta_2` and hence the ray bends towards normal after entering denser medium from rarer medium.