Question

A ray of light is incident on a medium at an angle ${60}^{\circ }$.

The angle of refraction is different for different mediums for an angle of incidence $={60}^{\circ }$.

In which medium the speed of light is slowest?

• A. 1
• B. 2
• C. 3
• D. same in all

Answer 1

The correct option is C

3

The angle of refraction for the different media are:
$Medium1={60}^{\circ }Medium2={45}^{\circ }Medium3={30}^{\circ }$.

As we know, light while entering a denser medium from a rarer medium gets slowed down that is why it is bending towards the normal and vice-versa.
So, using this concept, the densest medium is medium 3 as light bends by the maximum amount in medium 3.
Therefore the speed of light is minimum in medium 3.