Two parallel rays of red and violet colour pass through a glass slab. Which of the following is correct?

$A$ glass hemisphere of radius $0.04\, m$ and refractive index $1.6$ is placed centrally over a cross mark on a paper:
$(i)$ with the flat face in contact with the paper;
$(ii)$ with the curved face in contact with the paper.
In each case,the cross mark is viewed directly from above. The positions of the images will be:

Three immiscible liquids of densities $d_1 > d_2 > d_3$ and refractive indices $\mu_1 > \mu_2 > \mu_3$ are put in a beaker. The height of each liquid column is $\frac{h}{3}$. $A$ dot is made at the bottom of the beaker. For near normal vision,find the apparent depth of the dot.

$A$ ray of light is incident from air on a glass plate having thickness $\sqrt{3} \, cm$ and refractive index $\sqrt{2}$. The angle of incidence of the ray is equal to the critical angle for the glass-air interface. The lateral displacement of the ray when it passes through the plate is $....... \times 10^{-2} \, cm$ (given $\sin 15^{\circ} = 0.26$).

$A$ paraxial beam of light is converging towards a point $P$ on the screen. $A$ plane parallel sheet of glass of thickness $t$ and refractive index $\mu$ is introduced in the path of the beam. The convergence point is shifted by:

$A$ plane mirror is placed at the bottom of a tank containing a liquid of refractive index ' $\mu$ '. ' $P$ ' is a small object at a height ' $h$ ' above the mirror. An observer ' $O$ ' vertically above ' $P$ ' outside the liquid sees ' $P$ ' and its image in the mirror. The apparent distance between these two will be