Question

When light travels from denser to rarer medium, the velocity of light:

• A. Decreases
• B. Increases.
• C. Remains The Same
• D. None Of These.

Answer 1

The correct option is B

Increases.

The explanation of the correct option (B):

1. The light will move more slowly through an optically denser medium than it would through a less dense one (optically rarer).
2. The speed of light rises when it moves from a denser to a more rare medium, which causes it to bend away from its typical path.
3. As a result, light moves faster while moving from a denser to a rarer medium.

The explanation for the incorrect options (A), (C), and (D):

Medium:

1. A translucent substance that allows light to pass through is called a medium.
2. A medium where the speed of light is faster is optically rarer. The air is an optically rarer medium than glass and water.
3. Media with higher optical densities have slower light speeds.
4. The optical density of a medium is a measure of the speed of light there. It is the difference between how fast light travels through that medium and how fast light travels through a vacuum.
5. Therefore, it is claimed that the optical density of a medium is inversely proportional to the speed of light in that medium.

Therefore, the correct option is B.