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SPLITTING OF WHITE LIGHT:
 Dispersion of light: The splitting of white light into its seven constituent colours while
passing through a transparent medium such as a glass prism is called ‘dispersion of
light’.
 Rainbow is a natural phenomenon formed by the dispersion of white light of the sun
through transparent water droplets present in the air.
 It consists of seven colours and this band of seven colours is known as spectrum.
 The colours of the spectrum are denoted by VIBGYOR, that is, violet, indigo, blue, green,
yellow, orange, red.
 During dispersion, violet colour bends the most as it has the lowest wavelength. Red
colour bends the least as it has the highest wavelength.

 PRISM: A prism is a transparent medium with three rectangular and two triangular faces.

NEWTON’S DISC
 Newton’s disc is a device which proves white light consists of seven colours.
 A Newton’s disc is made by painting a disc with the seven colours (VIBGYOR). When the
disc is rotated very fast, the colours of the disc disappear and appear white. Thus, we
say that when the seven constituent colours of white light combine together, they appear
white.

Suggested Activity: Make a Newton’s Disc.