Te Reo Physics Resources

Multimedia Physics and Science Teaching Resources




A primer on transformers and their use in the electricity distribution grid.

Principles Illustrated
Electromagnets and electromagnetic induction. How transformers work. This is a background information resource that should be used before the jumping ring and boil up demonstrations. It is also useful background for the hydroelectric, wind, and bicycle generator videos. As a stand-alone, it is useful for the level 3 physics curriculum.



English version


This short video provides background for the hydroelectric generator, wind generator, and Bicycle Generator videos.
Transformer demonstrations You can find demonstration transformers in educational equipment catalogues and small transformers are also available at electronics shops. Hook up a signal generator to either coil and a scope or AC voltmeter and ammeters to both coils. Note that transformers are typically designed to work around 50 Hz (mains frequency). Transformers designed for use at high frequency are constructed differently.

Transformer Diagram
Diagram of transformer from the video

Other Information


Transformers can produce dangerous voltages very easily. Make sure you understand the operation of the transformer and test it before class.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.

See Jumping Ring, Boil-up. See also the Electric Power Grid.

Notes, Applications, and Further Reading

The photo shows the first transformer, designed and built by Faraday himself. Faraday’s Transformer is owned by the Royal Institution in the UK. Have a look at their Faraday Museum Page for more information.
The image of Faraday in the video was provided by the Institute of Electrical and Electronics Engineers (IEEE). You can find a lot of useful information about electronic technology and and the history of electronics technology on their website.

Faraday Transformer
The world's first transformer, built by Faraday himself. Photo is from the Institute of Electrical and Electronic Engineers (IEEE).
Transformer with meters
A transformer with meters to measure voltages across the primary and secondary coils, and currents in these coils.


This teaching resource was developed by the Te Reo Māori Physics Project with support from