Q. When light enters water from the vacuum, then the wavelength of light
A) Decreases
B) Increases
C) Remain constant
D) Becomes zero
Explanation
(a) When light enters water from vacuum, then wavelength of light
$\lambda' = \frac{\lambda}{\mu}$
For water, $\mu > 1$
So,
$\lambda' < \lambda$
Hence, wavelength of light decreases, when light enter to water from vacuum.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.