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.
Solution:
Laws of refraction of light are:
1. The incident ray, refracted ray and the normal at point of incidence, all lie in the same plane.
2. The ratio of the sine of the angle of incidence I to the sine of angle of refraction is constant for the pair of given media.
Absolute refractive index of the medium is defines as the refractive index that medium with respect to refractive index vacuum i.e. ratio of refractive index of the given medium to that vacuum.
Absolute refractive index of medium:
n medium/ n vacuum = c/v
Where v is the speed of light in that medium, c is the speed of light in vacuum.
Laws of refraction of light are:
1. The incident ray, refracted ray and the normal at point of incidence, all lie in the same plane.
2. The ratio of the sine of the angle of incidence I to the sine of angle of refraction is constant for the pair of given media.
Absolute refractive index of the medium is defines as the refractive index that medium with respect to refractive index vacuum i.e. ratio of refractive index of the given medium to that vacuum.
Absolute refractive index of medium:
n medium/ n vacuum = c/v
Where v is the speed of light in that medium, c is the speed of light in vacuum.