Visible Light
Light, Sound and Waves

Colours in a television

Classroom Activity for 11-14 Supporting Physics Teaching

What the Activity is for

Investigating how colour is made in televisions.

To reinforce that the combination of different coloured beams of light can produce any colour. It can be used as a homework.

What to Prepare

  • A magnifying glass and a television (if magnifying glasses are not available, then a wet finger touched against a screen leaves a droplet behind that acts as a magnifying glass)

What Happens During this Activity

Pupils hold the magnifying glass up to the screen, really close, to see the triplets of dots: Red, blue and green. These triplets are used to generate the beams of light that make up the picture. You might get them to explain how any colour is generated from these three dots to an adult, then have the adult comment on the quality of the explanation as a means of having some record of the homework. You might like to ensure that they include an explanation of how black is generated (no light is emitted where none of the triplet will be producing a beam).

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