Senior ELP Science pupils tune in to television and radio…

 Episode One – “How do televisions and radios work?”

As part of the Senior ELP Science programme we have been learning about how televisions and radios work. This is part of an Intermediate I Physics unit we are undertaking but we are also just very interested in what goes on “inside the box”.



We have been discovering that radios have 6 important parts. They are shown here

The aerial collects signals sent from far away. The tuner helps you choose the right frequency/station. The decoder helps change that into a signal that is sent to the amplifier to be made stronger. The loudspeaker turns that signal into sound. All of this needs a power supply to make it work.


A television is a lot like a radio but it has two jobs to do – it has to produce pictures as well as sound. This means it has more important parts. They are shown below:

Just like the radio, it has an aerial to collect signal from far away. It also has a tuner to select the correct frequency/channel. However, the television has two decoders – one for sound and one for pictures. It also has two amplifiers – one for sound and one for pictures. The television has only one loudspeaker to turn the signal into soundwaves we can hear. It also has a tv tube which turns the vision signal into pictures on a screen. The television needs mains electricity to work. This is different to the radio which can be run on batteries.

 Tune in next time for…

“Episode Two – How do we make pictures using only 3 colours of light?”


Script  David Tracey

Director  Rachael Baillie

Producer Mrs Binnie

With thanks to Dr Voge

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