Question

Define the refractive index of a medium.

Answer 1

1. According to Snell's law, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for the light of a given color and for a given pair of media. This constant is known as the refractive index. Mathematically, $\frac{\sin \left(i\right)}{\sin \left(r\right)}{=}_1{\mu }_2\left(cons\tan t\right)$, where $i$ is the angle of incidence, $r$ is the angle of refraction, and${}_1{\mu }_2$is the refractive index of medium 2 with respect to medium 1.
2. It is also defined in terms of the speed of light. The refractive index of a medium is defined as the ratio of the speed of light in air to the speed of light in the medium.

Mathematically, ${}_1{\mu }_2=\frac{v_1}{v_2}$ where $v_1$ is the speed of light in the first medium, and $v_2$ is the speed of light in the second medium.