Define normal shift. Obtain an expression for normal shift when an object in a denser medium is viewed from a rarer medium.

What is the relation between the refractive index of water with respect to air $\left({}_{a }\mu _w\right)$, and the refractive index of air with respect to water $\left({}_{w }\mu _a\right)$.

Light enters from air to glass plate having $1.50$ refractive index. What is the speed of light in glass? (Given-speed of light in vacuum $3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$)

Light enters from air to kerosene having refractive index of $1.47$. What is the speed of light in kerosene, if the speed of light in air is $3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$?

A fish seems to be at the depth of $75 \mathrm{cm}$ from the surface of a pond, then find out its actual depth from the surface. (Given-refractive index of water $\frac{4}{3}$)

"Ray of light travels from optically rarer medium to optically denser medium, it moves towards normal and when it travels from optically denser to optically rarer medium it moves away from the normal is known as refraction of light". Which of the following pentagon figures shows the correct refraction of light.

If the refractive index of water with respect to air (${}_{a }\mu _w$)  is $\frac{5}{3}$.  Calculate the refractive index of air with respect to water (${}_{w }\mu _a$).