Dispersive power depends on the following:

Mention the constituent colors of white light.

Let us list some of the factors,which could possibly influence the speed of wave propagation:
$(i)$ nature of the source.
$(ii)$ direction of propagation.
$(iii)$ motion of the source and/or observer.
$(iv)$ wavelength.
$(v)$ intensity of the wave.
On which of these factors,if any,does
$(a)$ the speed of light in vacuum,
$(b)$ the speed of light in a medium (say,glass or water),depend?

Two incident monochromatic waves whose wavelengths differ by a small amount $d\lambda$ are separated angularly at $\theta$ and $\theta + d\theta$ with respect to the incident ray. The dispersive power is given by

If the refractive indices of crown glass for red,yellow,and violet colours are $1.5140, 1.5170$,and $1.5318$ respectively,and for flint glass these are $1.6434, 1.6499$,and $1.6852$ respectively,then the dispersive powers for crown and flint glass are respectively:

$A$ 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: