The refractive index of glass is $\frac{3}{2}$ and that of water is $\frac{4}{3}$. The critical angle for a ray of light going from glass to water is

What should be the maximum acceptance angle at the air-core interface of an optical fibre if $n_1$ and $n_2$ are the refractive indices of the core and the cladding,respectively?

$A$ ray of light in a liquid of refractive index $1.4$ approaches the boundary surface between the liquid and air at an angle of incidence whose sine is $0.8$. Which of the following statements is correct about the behavior of the light?

There is a small source of light at some depth below the surface of water (refractive index $= 4/3$) in a tank of large cross-sectional surface area. Neglecting any reflection from the bottom and absorption by water,the percentage of light that emerges out of the surface is (nearly) ..........$\%$. [Use the fact that the solid angle subtended by a cone of semi-vertical angle $\theta$ is $\Omega = 2\pi(1 - \cos\theta)$]

$A$ monochromatic beam of light is incident at the interface of two materials of refractive index $n_{1}$ and $n_{2}$ as shown. If $n_{1} > n_{2}$ and $\theta_{C}$ is the critical angle,then which of the following statements is $NOT$ true?

Various optical processes are involved in the formation of a rainbow. Which of the following provides the correct order in time in which these processes occur?