Question

Write a short note on the speed of light.

Answer 1

Light:

1. It is also defined as radiation that makes visible to the human eye.
2. Light is an electromagnetic wave transverse in nature and does not need any medium to travel. Light travels in a vacuum or air with the maximum speed.
3. The speed of light in the different medium are given below in the table:

Medium	Speed of light
Vacuum	$\text{c}=3\times {10}^8{\text{ms}}^{-1}$
Air	$\text{v}=3\times {10}^8{\text{ms}}^{-1}$
Water	$\text{v}=2.25\times {10}^8{\text{ms}}^{-1}$
Turpentine oil	$\text{v}=2.04\times {10}^8{\text{ms}}^{-1}$
Glass	$\text{v}=2\times {10}^8{\text{ms}}^{-1}$