Question

Assertion : When a light wave travels from a rarer to a denser medium, its speed decreases. The decrease in speed imply a reduction in energy carried by the light wave.
Reason : The energy of a wave is inversely proportional to velocity of wave.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

When a light wave travel from a rarer to a denser medium, its speed decreases but energy carried by the wave remains constant. It depends on the amplitude of wave. The frequency also remains constant.