Question

The figure shows the path of a ray of light, through a rectangular glass block in a liquid of uniform density.

Does the light speed up or slow down in glass ? Give reason to your answer.

• A. Lights slows down in glass because speed of light is less in water.
• B. Light slows down in glass because refractive index of water is less than glass.
• C. Light speed up in glass because refractive index of glass is more than water.
• D. Light speed up in glass because refractive index of water is more than glass.

Answer 1

The correct option is B Light slows down in glass because refractive index of water is less than glass.

$\mu =\frac{3}{2}\left(forglass\right)\mu =\frac{4}{3}\left(forwater\right)$

$\mu \propto \frac{1}{v}$

So, as the $\mu$ is more speed will be less as inversely proportional.

So, light will slow down in glass