Refractive index of diamond with respect to glass is $1.6$ and absolute refractive index of glass is $1.5$. Find out the absolute refractive index of diamond.

The refractive index of diamond is $2.42$. What is the meaning of this statement?

In which medium is the speed of light the highest?

The figure below shows the refraction and emergence of a ray of light incident on a rectangular glass slab. Copy the diagram and mark the lateral displacement of the incident ray. Name the two factors on which the lateral displacement depends.

The following table gives the values of refractive indices of a few media:

$S.No.$	$1$	$2$	$3$	$4$	$5$
Medium	Water	Crown glass	Rock salt	Ruby	Diamond
Refractive index	$1.33$	$1.52$	$1.54$	$1.71$	$2.42$

Use this table to give an example of $(i)$ a medium pair so that light speeds up when it goes from one of these media to another. $(ii)$ a medium pair so that light slows down when it goes from one of these media to another.

$(a)$ State the laws of refraction.
$(b)$ $A$ ray of light enters from a medium $A$ into a slab made up of a transparent substance $B$ (as shown in the figure). The refractive indices of medium $A$ and $B$ are $2.42$ and $1.65$ respectively. Complete the path of the ray of light until it emerges out of the slab.