Lala Lajpath Rai along with Madan Mohan Malavya founded the Nationalist Party
- Pigment is an optically active substance, which will absorb most of the colours of white light, but will selectively reflect one or more colours.
- The colour of an opaque object depends upon the wave bands it absorbs, reflects or transmits when white light is incident on it. If an object reflects all the colours, it appears white. If it absorbs all the colours, it appears black.
- The colour of the transparent object in white light depends upon
(i) colours of white light being absorbed and
(ii) colours of white light being transmitted.
- Red, blue and green are primary colours.
- Cyan, yellow and green are primary pigments.