Lala Lajpath Rai along with Madan Mohan Malavya founded the Nationalist Party
- A light, which is a mixture of several colours is called poly-chromatic light. White light is a poly-chromatic light and has all the seven wave-bands present in it.
- The phenomenon due to which a poly-chromatic light splits into component colours, when passed through a prism, is called dispersion.
- The angle through which light of a particular wave length can deviate, while passing through prism, is called refrangility.
- The refrangility for red light is least, whereas that of the violent light is maximum.
- As the velocity of light is least in case of violet and maximums in case of red in the glass, therefore refractive index of red colour is glass is less than violet colour.