Why does light change its path as the medium changes during the transit?

When light travels from one medium to another, its speed changes. So it causes a slight change in direction. This change of direction is called refraction. 

The amount of bending depends on:

Change in speed:
If a substance causes the light to speed up or slow down more, it will refract (bend) more.

The angle of the incident ray with normal:
If the light is entering a new medium at a greater angle, the amount of refraction will also higher. But, if the light is entering the new substance with normal incidence (at 90° to the surface), the light will slow down, but it won’t change direction.


Simply Easy Learning

Updated on: 10-Oct-2022


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