$A$ ray of light travels from a medium of refractive index $\mu$ to air. Its angle of incidence in the medium is $i$,measured from the normal to the boundary,and its angle of deviation is $\delta$. If $\delta$ is plotted against $i$,which of the following best represents the resulting curve?

Light enters at an angle of incidence $\alpha$ into a transparent rod of refractive index $n.$ For what value of the refractive index of the material of the rod will the light,once entered into it,not leave it through its lateral face,regardless of the value of the angle of incidence $\alpha$?

In the figure shown,for an angle of incidence $45^{\circ}$ at the top surface,what is the minimum refractive index $\mu$ needed for total internal reflection at the vertical face?

$A$ point source of light is kept below the surface of water $(n_{w} = 4/3)$ at a depth of $\sqrt{7} \ m$. The radius of the circular bright patch of light noticed on the surface of water is

$A$ vertical pencil of rays comes from the bottom of a tank filled with a liquid. When the tank is accelerated horizontally with an acceleration of $7.5\, m/s^2$,the ray is seen to be totally internally reflected by the liquid surface. What is the minimum possible refractive index of the liquid? (Take $g = 10\, m/s^2$)

An endoscope is employed by a physician to view the internal parts of a body organ. It is based on the principle of