Question

# Light travels ___________(Faster, slower) in air, but_________ (Faster, slower) in glass.A. Faster, faster respectivelyB. Slower, faster respectivelyC. Faster, slower respectivelyD. None

As we know, $v$ is equal to the speed of light in any medium. $c$ is equal to the speed of light in the vacuum. $\mu$ is equal to the permeability of the medium. The relation between the above 3 constants is given by –
$v = \dfrac{c}{\mu }$
Value of $c$ is constant that is $3 \times {10^8}m/s$ thus $v \propto \dfrac{1}{\mu }$