$A$ ray of light travels from a medium of refractive index $2$ to another medium of refractive index $\sqrt{2}$. Total internal reflection takes place when the angle of incidence is

$A$ light ray traveling in a glass medium is incident on a glass-air interface at an angle of incidence $\theta$. The reflected $(R)$ and transmitted $(T)$ intensities,both as functions of $\theta$,are plotted. The correct sketch is:

$A$ beam of light consists of red,green,and blue colors. It is incident on the $AB$ face of a right-angled prism as shown in the figure. The refractive indices for red,green,and blue colors are $1.39$,$1.44$,and $1.47$ respectively. What will a person see when looking at the $AC$ surface of the prism?

$A$ light ray falls on a glass surface of refractive index $\sqrt{3}$,at an angle of $60^{\circ}$. The angle between the refracted and reflected rays would be ....... $^o$.

The phenomenon involved in the reflection of radio waves by the ionosphere is similar to:

$A$ step index fibre has a relative refractive index difference of $0.88\%$. What is the critical angle at the core-cladding interface in degrees?