State the laws of refraction of light. Explain the term absolute refractive index of a medium

State the laws of refraction of light. Explain the term ‘absolute refractive index of a medium’ and write an expression to relate it with the speed of light in vacuum.

Answer

1st law: the incident ray, refracted ray and normal to the interface at the point of incidence lie in the same plane.

2nd law: The sine of angle of incidence bears a constant ratio with sine of angle of refraction for a given pair of media.

sin i / sin r = constant

Absolute Refractive Index of a medium = (Speed of light in air or vacuum) / (Speed of light in the medium)

• Exam Year: 2018