$A$ beam of initially parallel cylindrical light rays travels in a medium with a refractive index $\mu(I) = \mu_0 + \mu_2 I$,where $\mu_0$ and $\mu_2$ are positive constants and $I$ is the intensity. As the intensity of the beam decreases with radius,the speed of light in the medium is:

Time taken by light to travel in two different materials $A$ and $B$ of refractive indices $\mu_{A}$ and $\mu_{B}$ of the same thickness is $t_{1}$ and $t_{2}$ respectively. If $t_{2}-t_{1}=5 \times 10^{-10} \text{ s}$ and the ratio of $\mu_{A}$ to $\mu_{B}$ is $1:2$. Then the thickness of the material,in meters,is: (Given $v_{A}$ and $v_{B}$ are velocities of light in $A$ and $B$ materials respectively).

What are optically denser and optically rarer media?

$A$ ray of light is incident at $30^{\circ}$ from a medium of refractive index $2$ into a medium of refractive index $1$. The angle of refraction is: (in $^{\circ}$)

The angles of incidence and refraction of a monochromatic ray of light of wavelength $\lambda$ at an air-glass interface are $i$ and $r$,respectively. $A$ parallel beam of light with a small spread $\delta \lambda$ in wavelength about a mean wavelength $\lambda$ is refracted at the same air-glass interface. The refractive index $\mu$ of glass depends on the wavelength $\lambda$ as $\mu(\lambda)=a+b / \lambda^2$,where $a$ and $b$ are constants. Then,the angular spread in the angle of refraction of the beam is

If the speed of light in vacuum is $C \ m/s$,then what is the velocity of light in a medium of refractive index $1.5$?