What is dispersion of light?

$A$ convex lens,a glass slab,a glass prism,and a solid sphere are all made of the same glass. The dispersive power will be:

$A$ parallel beam of white light falls on a convex lens. Images of blue,yellow,and red light are formed on the other side of the lens at distances of $0.20 \ m$,$0.205 \ m$,and $0.214 \ m$ respectively. The dispersive power of the material of the lens will be:

When white light enters a prism,it gets split into its constituent colours. This is due to

The angle of a prism is $10^o$. The refractive indices for red and violet colours are $1.51$ and $1.52$ respectively. Find the dispersive power.

The refractive index of flint glass for blue $F$ line is $1.6333$ and red $C$ line is $1.6161.$ If the refractive index for yellow $D$ line is $1.622,$ the dispersive power of the glass is