$A$ bird is looking at a fish underwater from the air. $h_1$ is the height of the bird above the water surface and $h_2$ is the depth of the fish below the water surface. If $\mu$ is the refractive index of water with respect to air,then the distance of the fish as observed by the bird is:

$A$ monochromatic light wave is incident normally on a glass slab of thickness $d$,as shown in the figure. The refractive index of the slab increases linearly from $n_1$ to $n_2$ over the height $h$. Which of the following statement$(s)$ is (are) true about the light wave emerging out of the slab?

$A$ parallel-sided block of glass with a refractive index of $1.5$ and a thickness of $36 \, mm$ rests on the floor of a tank filled with water (refractive index $= 4/3$). The difference between the apparent depth of the floor at $A$ (where the glass block is present) and $B$ (where only water is present) when seen from vertically above is equal to $....... \, mm$.

An air bubble in a glass slab of thickness $15 \, cm$ appears to be at $6 \, cm$ from one side and at $4 \, cm$ from the opposite side. The refractive index of the glass is:

$A$ tiny air bubble in a glass slab $(\mu = 1.5)$ appears from one side to be $6 \, cm$ from the glass surface and from the other side,$4 \, cm$. The thickness of the glass slab is......$cm$

$A$ small pin fixed on a table top is viewed from above from a distance of $100 \ cm$. By what distance would the pin appear to be raised if it is viewed from the same point through a $9 \ cm$ thick glass slab held parallel to the table (in $cm$)? The refractive index of glass is $1.5$.