Question

What is the refractive index of a medium?

Answer 1

Hint: The speed of light in vacuum to the speed of light in the medium is called the refractive index of the medium. It is usually represented by ‘n’. The refractive index of one material varies from that of other materials. Refractive index of a material is a dimensionless quantity.

Formula used:
\[n=\dfrac{c}{v}\]
Where, n is the refractive index of a medium
c is the velocity of light
v is the velocity of the medium

Complete step-by-step solution:
The speed of light in vacuum to the speed of light in the medium is called the refractive index of the medium. It is usually represented by ‘n’. When light travels from one medium to another the atoms present in that medium will absorb some atoms thereby decreasing the velocity of the particle.
\[n=\dfrac{c}{v}\]
Where, n is the refractive index of a medium
c is the velocity of light that has the value $3\times {{10}^{8}}\dfrac{m}{s}$.
v is the velocity of the medium
Refractive index of a material is a dimensionless quantity. Since it is the ratio of the speed of light in vacuum to the speed of light in the medium. The value of the refractive index for water is 1.33. As the refractive index is increasing the velocity of the medium decreases.

Note: In general we can say refractive index as how fast the light beam can travel through a material and it is also the measure of how much the path of light is bent while entering a material. Refractive index of a material is a dimensionless quantity.