State the laws of refraction of light. If the speed of light in vacuum is 3 X10 ^8 m/s, find the absolute refractive index of a medium in which light travels with a speed of 1.4 X10 ^8 m/s.

**Answer:**

**Laws of refraction of light:**

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

**Second law** **(Snell’s law):** The ratio of sine of angle of incidence to the sine of angle of refraction is a constant for a given pair of media.