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

Time taken by the sunlight to pass through a window of thickness $4 \, mm$ whose refractive index is $1.5$ is

$A$ glass slab of thickness $4.8 \text{ cm}$ is placed on a piece of paper on which an ink dot is marked. By how much distance would the ink dot appear to be raised (in $\text{ cm}$)? (The refractive index of glass $= 1.5$)

The observer at $O$ views two closely spaced spots on a vertical wall through an angled glass slab as shown. As seen by the observer,the spots appear

The bottom of a container is a glass slab of thickness $4 \ cm$ and refractive index $\mu = 1.5$. The container contains two immiscible liquids $A$ and $B$ of depths $6 \ cm$ and $8 \ cm$ respectively. When a crack at the bottom surface of the glass slab is viewed from above,by what distance (in $cm$) does it appear to be shifted? The refractive indices of $A$ and $B$ are $1.4$ and $1.3$ respectively.

$A$ 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?