What is dispersion of light? Will there be dispersion of white light within a glass slab after refraction when white light is incident on the glass slab at an angle of ${45}^{\circ }$?

The principal section of a prism is an equilateral triangle. If a ray of light is incident at an angle of ${30}^{\circ }$ on one of the refracting surfaces and emerges at an angle of ${45}^{\circ }$ from the other refracting surface, what is the angle of deviation?

What will be the velocity and wavelength of light in a medium of refractive index $1.5$ if the wavelength of the light is $6000 \stackrel{\circ }{\mathrm{A}}$ in air medium?. Take the speed of light in air$=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$.

What is a diverging lens?

Mention one function of lens of eyeball.

To rectify which defects in the eye's vision, spectacles of convex lens and concave lens are used?

Write the names of the different refractive medium of eyeball in proper sequence.

A person can see distant objects distinctly but is unable to see nearby objects in a perfect way. Predict the probable cause and suggest the corrective measure for such problem.