Question

When a light wave goes from air into water, the quality that remains unchanged is its

• A. Speed
• B. Amplitude
• C. Frequency
• D. Wavelength

Answer 1

Answer: (C)

Frequency

Answer 2

Let $v ^ { \prime }$and $\lambda ^ { \prime }$represents frequency and wavelength of light in medium respectively.

so $v ^ { \prime } = \frac { v } { \lambda ^ { \prime } } = \frac { c / \mu } { \lambda / \mu } = \frac { c } { \lambda } = v$