According to Maxwell’s equation the velocity of light in any medium is expressed as
Answer & explanation
Correct answer: option 2
Velocity of light in a medium,
$ v =\frac{c}{\sqrt{\mu_r ε_r}}={\frac{1}{\sqrt{\mu_0 ε_0 \mu_r ε_r}}}=\frac{1}{\sqrt{\mu ε}}$