Colours of light by 2E2 Liow Fang Yu

Colours of light
I learnt that sunlight may appear white, but it is actually made up of a mixture of seven colours. When the sunlight passes through the rain drop, the raindrop split the white sunlight into a range or spectrum of colours. The colours that makes the spectrum are red, orange, yellow, green, blue, indigo and violet.

We can see the colours of the spectrum, so it is called the visible spectrum . I learnt that I can also remember the order of the seven colours as a boy’s name: ROY G BIV

I learnt that when the splitting or separation of whit light into a spectrum of colours is called the dispersion of white light.

As the refracted colours of light leave the prism, they are bent again, but not in their original paths. This is because the face of the prism through which the light leaves is not parallel to the face through which it enters.

I learnt that to prove that white light is a mixture of different colours, another prism can be used to recombine the colours of its spectrum. Another way of combining the different colours of a spectrum is by spinning a rainbow-coloured disc called Newton’s disc.

I learnt that when a white light is a mixture of different colours, another prism can be used to recombine the colours of its spectrum. I learnt that white light and light of other colours can be obtained by lust mixing three colours. These three colours are red, blue and green. These three colours are called the primary colours of light.

Mixing the primary colours two at a time gives the following colours:
RED + BLUE = MAGENTA
RED + GREEN = YELLOW
BLUE + GREEN = CYAN

A colour television works in the same way. The picture on the television screen is made of dots of coloured light. A mixture of red, green and blue dots in different combinations and varying amounts of brightness produces the different colours in the picture.

These information can be found in : Interactive Science 2 (book) pg113 to119 and
Explore your world with science discovery 2 (book) pg128 to 130.