Laws of Refraction

The extent, to which a ray bends, depends not only on the refractive index of medium, but also on the angle of incidence.

The laws of refraction are:

1. First law of refraction: The incident ray, refracted ray and the normal at the point of incidence, all lie in the same plane.

2. Second law of refraction: How much ray of light refracted depends on that medium. The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant and equal to the refractive index of that medium. This law is also called Snell's law.

Refractive index (n) = (Sine of angle of incidence) / (Sine of angle of refraction)

n =  (sin i) / (sin r)

Does the colour of light change during refraction?

The wavelength and frequency of light are related to the velocity as v = νλ, where ν is frequency and λ is wavelength.