Dispersive power depends upon the nature of the material.
What is dispersive power?
Dispersive power of prism is defined as the measure of the difference in refraction of the light of the highest wavelength and the lowest wavelength that enters the prism. The dispersive power of the prism can also be expressed in terms of the angle between the two extreme wavelengths. As the dispersive power increases, the angle between them increases.
The SI unit of dispersive power of prism is Watt.
