An object in a denser medium when viewed from a rarer medium appears to be raised. The shift is maximum for :

A small coin is fixed at the center of the base of an empty cylindrical steel container having radius $R=1 \mathrm{m}$ and height $d=4 \mathrm{m}$. At time $t=0 \mathrm{s}$, the container starts getting filled with water at a flowrate of $Q=0.1 {\mathrm{m}}^3/\mathrm{s}$ without disturbing the coin. Find the approximate time when the coin will first be seen by the observer "$O$" from the height of $H=5.75 \mathrm{m}$ above and $L=1.5 \mathrm{m}$ radially away from the coin as shown in the figure. Refractive index of water is $n=1.33$.

A diver, $30 \mathrm{m}$ below water surface is trying to shine a torch light towards the point O which is horizontally $30 \mathrm{m}$ away. The amount and direction in which diver has to swim (in the figure) so that the light can not travel outside the surface of water is (Refractive index of water $=\frac{4}{3}$)

Complete the path of the ray AB through the glass prism in PQR till it emerges out of the prism. Given the critical angle of the glass as $42°$.

The position of fish in a pond is not same as it is observed from outside. Why? Explain with diagram.

In the case of refraction, if the angle of incidence and the angle of refraction are ${45}^{\circ }\mathrm{and} {30}^{\circ }$, respectively, then what will be the angle of deviation?

The refractive index of a medium with respect to air is $\sqrt{2}$. If the angle of incidence of a ray of light in air is ${45}^{\circ }$ determine the angle of deviation for that ray in case of refraction.

A cubical vessel has opaque walls. An observer (dark circle in the figure below) is located, such that she can see only the wall, $CD$, but not the bottom. Nearly to what height should water be poured, so that she can see an object placed at the bottom at a distance of, $10 \mathrm{cm}$, from the corner, $C$? Refractive index of water is, $1.33$.