Question

In the following, for which colour speed of light in water will maximum?

• A. Red
• B. Yellow
• C. Green
• D. Violet

Answer 1

The correct option is A Red

Speed of light in water is given by $v=\frac{c}{\mu }$
where $c$ is the speed of the light in vacuum and $\mu$ is the refractive index of water for that light.
Since $\mu$ of water is minimum for red colour.
Thus speed of light in water is maximum for red colour.