Question

1.What exactly do we mean by refractive index?
2.What happens if we perform the dispersion experiment under water?

Answer 1

1.
Definition of refractive index. : 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.
Refractive index, also called index of refraction, measure of the bending of a ray of light when passing from one medium into another.Refractive index is also equal to the velocity of light c of a given wavelength in empty space divided by its velocity v in a substance, or n = c/v.