Question

Refractive Index has no unit (magnitude) , How is it a Scalar Quantity?

Answer 1

Ya refractive index has no units and also it is a ratio but also it doesn't have any direction so it is considered as a scalar quantity.

Answer 2

Transparent medium have strength of bending light when it passes through it...This strength of bending the light is measured in terms of refractive index...

Refractive index of medium can be measured by taking the ratio of velocities of light travelling in two different media...

Here if we take ratio of two velocities , units of velocity of light gets cancel from Numerator and demomainator, So Refractive index have no unit....It has only magnitude...This magnitude specify the strength of light upto which it bend when it enter from one transparent medium to other....

For example...Just taking a rough values...Suppose we have two medium A and B
The refrative index of medium A is 1.33 say and Refrative index of medium B is 2.42....Here Medium B have greater magnitude than Medium A...it means When light enters the medium B , light bends more than that of medium A...

Hope this help......