A ray of laser of a wavelength 630 nm is incident at an angle of 30° at the diamond-air interface. It is going from diamond to air. The refractive index of diamond is 2.42 and that of air is 1. Choose the correct option.

Refractive index (n) is a dimensionless quantity that has no units. Since both numerator and denominator are in meters per seconds (m/s), both units cancel each other. This makes refractive index simply a number. 

Absolute refractive index is the ratio of speed of light in air/vacuum to speed of light in any medium. It is closely related to refractive index, except that it is relative to vacuum and not to any other medium. This is different from relative refractive index because it is the ratio of speed of li

This type of refraction is the bending of light rays when they pass through the atmosphere of Earth because of the change in the air density. The density of air varies with pressure and temperature. 

Due to the atmospheric refraction, celestial objects appear higher than they actually are. This

The refractive index is an optical property of the material that describes how much does the light bend or refract while passing from one medium to another. It is the ratio of spee of light in vacuum (c) to speed of light in a material (v)$n=\frac{c}{v}$ Refractive index is the reason which causes refraction. When