Three historic discoveries were instrumental in the development of electric motors – the invention of the battery by Alessandro Volta in 1800, the generation of a magnetic field from electric current by Hans Christian Ørsted in 1820 and the invention of the electromagnet by William Sturgeon in 1825. These discoveries were critical for the development of building working electric motors.
Electricity and magnetism are forces caused by the movement of electrons. Electrons are negatively charged particles in atoms that can move through conductors such as copper wire when the wire is connected in a circuit from one battery terminal to the other. The negatively charged electrons in the wire move away from the negative terminal of the battery towards the positive terminal. The movement of electrons through a conductor is called an electric current.
A magnet is formed when atoms of certain materials are lined up so that the negatively charged electrons all spin in the same direction. The magnetic field is the area around the magnet where the force is active. Stronger magnets have larger magnetic fields. A magnet can be created by electricity. Wrapping a wire around metal and running an electric current through it creates a magnetic force. This is called electromagnetism.
This activity will demonstrate electromagnetism operating in a basic electric motor that students build. It can be approached from a science perspective or a technology perspective.
By the end of this activity, students should be able to:
- understand how a simple electrical motor works
- construct a simple electrical motor
Download the Word file (see link below) for:
- introduction/background notes
- what you need
- what to do
- extension ideas
- student handout.
Electric cars have been around a lot longer than you may think. Have a look at the Electric car history timeline and a Participatory Science Platform (PSP) project in Taranaki called REV it UP, where students are building an electric vehicle.
Nature of science
Scientific discoveries often contribute to the development of new technologies, while new technologies often enable new scientific discoveries to be made.