How many times is the velocity of light in a vacuum compared to the velocity of light in water?

What is the absolute refractive index of common glass?

$A$ light ray enters from medium $A$ to medium $B$ as shown in the figure. The refractive index of medium $B$ relative to $A$ will be

The absolute refractive indices of glass and water are $4/3$ and $3/2$ respectively. If the speed of light in glass is $2 \times 10^{8} \ m \ s^{-1}$,calculate the speed of light in $(i)$ vacuum,$(ii)$ water.

Which symbol is used for the refractive index?

You are given kerosene,turpentine,and water. In which of these does the light travel fastest? Use the information given in the table below.

Material medium	Refractive index
Water	$1.33$
Kerosene	$1.44$
Turpentine oil	$1.47$