Light is incident normally on face $AB$ of a prism as shown in the figure. $A$ liquid of refractive index $\mu$ is placed on face $AC$ of the prism. The prism is made of glass of refractive index $\frac{3}{2}$. The limit of $\mu$ for which total internal reflection takes place on face $AC$ is

$A$ 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?

$A$ glass prism whose cross-section is an isosceles triangle stands with its (horizontal) base in water; the angles that its two equal sides make with the base are each $\theta$. An incident ray of light,above and parallel to the water surface,is totally internally reflected at the glass-water interface and subsequently re-emerges into the air. Take the refractive indices of glass and water to be $\frac{3}{2}$ and $\frac{4}{3}$,respectively. The maximum value of $\cos\theta$ is:

'Mirage' is a phenomenon due to

On which principle does an optical fiber work?

The critical angle for a denser-rarer interface is $45^{\circ}$. The speed of light in the rarer medium is $3 \times 10^8 \, m/s$. The speed of light in the denser medium is: