Question

What among the following is true about refraction?

• A. Velocity of light in rarer optical medium is greater compared to the denser medium.
• B. Velocity of light in rarer optical medium is lesser compared to the denser medium.
• C. Refraction does not happen in more than two media.
• D. Refraction can happen only when light travels from an optically rarer medium to a denser medium.

Answer 1

The correct option is A Velocity of light in rarer optical medium is greater compared to the denser medium.

Velocity of light depends on the nature of the medium in which it travels. Velocity of light in a rarer medium (optical density) is more than in denser medium (high optical density). Hence, velocity decreases when light moves form rarer to denser. This is the basic cause of bending of light during refraction.