What is refractive index?

Dear Student ,
Refractive index , also called index of refraction, is the measure of bending of path of light when it enters one medium into another . It is also defined as the ratio of the sine of the angle of incidence to sine of angle of refraction , or is also equal to the velocity of light in vacuum i.e. c of a given wavelength divided by velocity of light , v , in that medium .

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