Explain how spectrum is formed.

i.    The phenomenon of splitting of white light into its component colours is dispersion.


ii.  The various colours in the spectrum of light are in the sequence:  Violet, indigo, Blue, Green, Yellow, Orange and Red.


iii.  White light actually consists of rays of seven different colours. When rays of ‘white’ light pass through a refracting medium (such as a glass prism or droplets of water) the rays of seven different colours bend to different extent.


iv. Shorter the wavelength of the light, the greater is it refracted. Hence violet coloured rays bend the most as they emerge as they are of shorter wavelength.

v. Red coloured rays bend the least as they have longer wavelength. These effects cause the ‘white’ light to seperate into a band of seven different colours forming a spectrum.