Question

Light enters from air to kerosene having refractive index of 1.47. What is the speed of light in kerosene, if the speed of light in air is $3\times {10}^8$ m/s?

Answer 1

Given: Light enters from air to kerosene having refractive index of 1.47. The speed of light in air is $3\times {10}^{8}m/s$

To find the speed of the light in kerosene

Solution:

We know,

$\text{Refractive index of the medium}=\frac{\text{Speed of light in air}}{\text{Speed of light in the medium}}$

Hence,

$\text{Refractive index of the kerosene}=\frac{\text{Speed of light in air}}{\text{Speed of light in the kerosene}}⟹1.47=\frac{3\times {10}^8}{\text{Speed of light in the kerosene}}⟹\text{Speed of light in the kerosene}=\frac{3\times {10}^8}{1.47}⟹\text{Speed of light in the kerosene}=2.04\times {10}^{8}m/s$

is the required speed of light in kerosene.