Question

The frequency of a light ray is $6\times {10}^{4}Hz$ . Its frequency when it propagates in a medium of refractive index $1.5$, will be:

• A. $1.6\times {10}^{14}Hz$
• B. $9.10\times {10}^{14}Hz$
• C. $6\times {10}^{14}Hz$
• D. $4\times {10}^{14}Hz$

Answer 1

Answer: (C)

When a ray of light passes from one medium to another, then its frequency does not change, but its speed and wavelength change. Hence, its frequency in a medium of refractive index $1.5$ is $6\times {10}^{14}Hz$ .
Note: Intensity of light also changes, because a part of it is reflected.