Question

what is refractive index?​

Answer 1

Explanation:

In optics, the refractive index of a material is a dimensionless number that describes how fast light travels through the material. It is defined as where c is the speed of light in vacuum and v is the phase velocity of light in the medium

Answer 2

Explanation:

refractive index n=c/v

that is n-absolute refractive index

c-speed of light in vacuum or air

v-speed of light in medium