Question

Relation between absolute and relative refractive index

Answer 1

✔The absolute refractive index is defined as a ratio of the speed of light in vacuum and in selected medium. Generally, the refractive index depends on the wavelength of incident light. Relative refractive index is defined as a ratio of speeds of light in two different media.

Answer 2

When the angle of incidence is equal to the critical angle, the angle of refraction is equal to 90°. If the angle of incidence is bigger than this critical angle, the refracted ray will not emerge from the medium, but will be reflected back into the medium. This is called total internal reflection.