Q. When light propagates through a material medium of relative permittivity $\epsilon_r$ and relative permeability $\mu_r$, the velocity of light, v is given by : (c - velocity of light in vacuum)
A) $v = \frac{c}{\sqrt{\epsilon_r \mu_r}}$
B) v = c
C) $v = \sqrt{\frac{\mu_r}{\epsilon_r}}$
D) $v = \sqrt{\frac{\epsilon_r}{\mu_r}}$
Explanation
[Solution] $v = \frac{1}{\sqrt{\mu\epsilon}} = \frac{1}{\sqrt{\mu_0\epsilon_0}\sqrt{\mu_r\epsilon_r}} = \frac{c}{\sqrt{\epsilon_r\mu_r}}$. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.