Question

Assertion When monochromatic light is incident on a surface separating two media, the reflected and refracted light both have the same frequency as the incident frequency.
Reason Speed of light and wavelength of light both changes in refraction and hence, the ratio $v=c/\lambda$ is a constant.

• A. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is incorrect but Reason is correct.

Answer 1

Answer: (B)

Reflection and refraction arise through interaction of incident light with constituents of matter. Atoms may be viewed as oscillators, which take up the frequency of the external agency (light) causing forced oscillations. The frequency of light emitted by a charged oscillator equals its frequency of oscillation. Thus, the frequency of scattered light equals the frequency of incident light.