$A$ monochromatic ray of light travels through a glass slab and a water column. The number of waves in a glass slab of thickness $4 \,cm$ is the same as in a water column of height $5 \,cm$. If the refractive index of glass is $\frac{5}{3}$, then the refractive index of water is:

White light is incident normally on a glass slab. Inside the glass slab,

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.

$A$ glass beaker is filled with water up to $5 \,cm$. It is kept on top of a $2 \,cm$ thick glass slab. When a coin at the bottom of the glass slab is viewed at normal incidence from above the beaker,its apparent depth from the water surface is $d \,cm$. The value of $d$ is close to ........ $cm$ (the refractive indices of water and glass are $1.33$ and $1.5$,respectively).

$AB$ is an object of length $l$ dipped in water at a depth of $d$. It is viewed from air at near-normal incidence. The length of the image is

$A$ beaker contains water up to a height of $h_1$ and kerosene above the water up to a height of $h_2$. The total height is $(h_1 + h_2)$. The refractive index of water is $\mu_1$ and that of kerosene is $\mu_2$. What is the apparent shift of the bottom of the beaker when viewed from above?