Question

Define the term refractive index of a medium in terms of velocity of light.

Answer 1

Hint: In order to deal with this question we will use the definition of refractive index and we will understand the term on the basis of different factors further for better understanding we will write its equation in terms of speed of light.

Complete step-by-step solution -

A medium's absolute refractive index is defined as the ratio of light speed in the vacuum (or air) to light speed in that medium i.e. , $n = \dfrac{c}{v}$
Refraction is the measure of a beam of light bending when transiting from one medium to another. If I is the angle of incidence of a ray in the vacuum (angle between the incoming ray and the perpendicular ray to the medium side, called the normal) and r is the angle of refraction (angle between the medium ray and the regular ray), the refractive index n is defined as the ratio of the angle of incidence sine to the angle of refraction sine;
i.e., $n = \dfrac{{\sin i}}{{\sin r}}$
Also the refractive index is equal to the speed of light c of a given wavelength in empty space divided into a substance by its velocity v, or:
$n = \dfrac{c}{v}$

Note- Refractive index, also called refraction index, measures the bending of a beam of light as it travels from one medium to another. For measuring solids, liquids, and gases, the refractive index is used. This is most widely used for calculating a solute concentration in an aqueous solution. It can also be used as a useful tool for differentiating between different types of gemstone because of the unique chatoyance that each stone displays.