Question

What is the unit for representing refractive index?

• A. $m/s$
• B. $ms$
• C. $m/s^2$
• D. $Ithasnounit$.

Answer 1

The correct option is D

$Ithasnounit$.

1. Refractive index of a medium is the ratio of the speed of light in vacuum to the speed of light in a given medium.
2. Because it is the ratio of quantities which are similar. Therefore it has no units.

Hence, the correct answer is option (D) i.e. $Ithasnounit$