Paragraph on “Is white light really coloured ?” complete paragraph for Class 9, Class 10, Class 11 and Class 12
Is white light really coloured ?
Have you ever seen a rainbow ? We see rainbow when there are lots of tiny drops of water in the air and the sun shines through them. Ordinarily sunlight is white and water is clear, so how do they give a coloured rain-bow?
The answer was discovered by Sir Isaac Newton, an English scientist who lived in the seventeenth century. Ordinary white light is actually made up of lots of different colours ! In a dark room Newton shone a ray of light through a ‘prism’ — a three-sided piece of glass. As the picture above shows, the white light was broken up into colours. The different colours go from deep violet to red and we call this range of colours the ‘spectrum’. If you take light of all the different colours of the spectrum and combine them you get white light again !
The fact that white light really contains lots of colours helps us understand why different things look different colours. We see objects because some light bounces off them and reaches our eyes. When white light falls on a leaf, for example, colours like red and blue are soaked up by the leaf. Only the green part of the light bounces off. That is why we see the leaf as green.