Question
Give the definition dispersion of light. Also, explain why does it take place? Draw a diagram to show the dispersion of white light by a glass prism.
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Answer
In the year $1665$, Newton discovered by his experiments with glass prisms that white light (like sunlight) consists of a mixture of lights of seven colours. Newton found that if a beam of white light is passed through a glass prism, then the white light splits to form a band of seven colours on a white screen. The band of seven colours formed on a white screen, when a beam of white light is passed through a glass prism, is known as spectrum of white light. The seven colours of the spectrum are Red, Orange, Yellow, Green, Blue, Indigo and Violet.
So, dispersion of light is phenomenon of splitting up of white light into seven colours on passing through a transparent medium like a glass prism. The formation of spectrum of seven colours indicates that white light is a mixture of seven colours. White light can be sunlight. So, now we can say that the sunlight consists of seven colours. We can mix these colours to get white light. This can be done by using Newton’s disc, let us try this.
So, dispersion of light is phenomenon of splitting up of white light into seven colours on passing through a transparent medium like a glass prism. The formation of spectrum of seven colours indicates that white light is a mixture of seven colours. White light can be sunlight. So, now we can say that the sunlight consists of seven colours. We can mix these colours to get white light. This can be done by using Newton’s disc, let us try this.
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