$A$ ray of light of frequency $5 \times 10^{14} \,Hz$ is passed through a liquid. The wavelength of light measured inside the liquid is found to be $450 \times 10^{-9} \,m$. Calculate the refractive index of the liquid.

$A$ mark at the bottom of a liquid appears to rise by $0.1 \ m$. The depth of the liquid is $1 \ m$. The refractive index of the liquid is

The refractive index of a medium is $\frac{3}{2}$. The speed of light in this medium is . . . . . . $ms^{-1}$. (Speed of light in vacuum is $c = 3 \times 10^{8} \,ms^{-1}$)

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

The refractive index of water with respect to air is $4/3$ and the refractive index of glass with respect to air is $3/2$. The refractive index of water with respect to glass is

The refractive index of the material of a crystal is $1.68$ and that of castor oil is $1.2$. When a ray of light passes from oil to the crystal,its velocity will change by a factor of: