Question

why does a ray change its path when it passes from one medium to another medium​

Answer 1

Answer:

Refraction

Explanation:

This is due to refraction in the medium.

The speed of light rays changes when the medium is changed and as a result the rays change its path

Answer 2

Here is your answer ---

A ray of light, passing from one medium to another undergoes refraction.

=> So what is refraction?

Refraction occurs when a light ray travels or passes from one medium to another. Normal plays an important role in the bending of light, i.e., Refraction. A normal is perpendicular to the interface.

=> What is the role of Normal in Refraction?

As I said above, Normal is perpendicular to the interface. If the light ray is going from --

• Rarer medium to denser medium, i.e, for ex - air to water, the light ray will bend closer to the Normal.

• Denser medium to rarer medium, i.e., for ex - water to air, the light rag will move away from the normal.

So now coming back to your question, the light ray will pass without any devitation or refraction if the incident ray is perpendicular, i.e.,90° to the interface.