What is refraction of light ? Explain laws of refraction.

Explanation

The direction of propagation of an obliquely incident ray of light that enters the other medium, changes at the interface of the two media. This phenomenon is called refraction of light. `(0^@ lt i lt 90^@)`

In figure, the surface separating two media PQ.
AB is incident ray, BC is refracted ray NN. `bot` PQ at B. `angle`ABN = incidence angle i, `angle`N.BC refraction angle r. `n_1` and `n_2` are refractiv indices of medium-1 and medium-2 respectively
Snell experimentally obtained laws of refraction
(i) The incident ray, the refracted ray and th normal to the interface at the point of incidence, all lie in the same plane.
(ii) The ratio of the sine of the angle o incidence to the sine of angle of refraction is constant.
`therefore(sini)/(sinr)=n_(21)` ... (1)
Here, `n_(21)` is a constant called the refractive index of the second medium with respect to the first medium. Equation is the well known Snell.s law of refraction.
`n_(21)` depends on the wavelength of light, but is independent of the angle of incidence.