Q. Absolute refractive indices of glass and water are $\frac{3}{2}$ and $\frac{4}{3}$. The ratio of velocity of light in glass and water will be
A) $4\ :3$
B) $8\ :7$
C) $8\ :9$
D) $3\ :4$
Explanation
(c) $v \propto \frac{1}{\mu} \Rightarrow \frac{v_{1}}{v_{2}} = \frac{\mu_{2}}{\mu_{1}} \Rightarrow \frac{v_{g}}{v_{w}} = \frac{\mu_{w}}{\mu_{g}} = \frac{4/3}{3/2} = \frac{8}{9}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.