Question

What is refractive index?​

Answer 1

Answer:

The ratio of the speed of radiation (such as light) in one medium (such as air, glass, or a vacuum) to that in another medium.

Answer 2

Hey MATE!!!

Refractive index is defined as the ratio of light in vaccum to the velocity of light in a medium through which it is passed.

Also it is defined as the ratio of wavelength of rays in vacuum to that of wavelength in medium.

Hope it helps

HAKUNA MATATA :))