If the speed of light in vacuum is $C \ m/s$,then what is the velocity of light in a medium of refractive index $1.5$?

$A$ beaker containing liquid is placed on a table,underneath a microscope which can be moved along a vertical scale. The microscope is focused,through the liquid,onto a mark on the table when the reading on the scale is $a$. It is next focused on the upper surface of the liquid and the reading is $b$. More liquid is added and the observations are repeated; the corresponding readings are $c$ and $d$. The refractive index of the liquid is

Light of wavelength $7200 \ \mathring{A}$ in air. It has a wavelength in glass $(\mu = 1.5)$ equal to.......$\mathring{A}$

The length of the optical path of two media in contact of lengths $d_1$ and $d_2$ with refractive indices $\mu_1$ and $\mu_2$ respectively,is

On heating a liquid,the refractive index generally

$AB$ is a boundary separating two media of different refractive indices. $A$ ray is incident on the boundary and is partially reflected and partially transmitted. Choose the $\text{CORRECT}$ statement.