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Explore how to make magnets using stroke & electrical methods, understand electromagnet uses like scrap iron crane & maglev train. Discover the science behind electromagnets!
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Questions to think about… What are the uses of electromagnets? What are the ways to make a magnet?
What are the ways to make a magnet? • Two ways to make a magnet: • the stroke method • the electrical method • When a magnetic object becomes a magnet, we say that it is magnetised. Let’s make magnets!
The stroke method • The iron filings are not attracted to a magnetic object such as an iron nail. To make the iron nail into a magnet, you will need a strong bar magnet.
The stroke method • First, stroke the iron nail at least 20 times with one pole of a bar magnet. • Make sure you stroke the iron nail with the same pole. • Always repeat the strokes in the same direction.
The stroke method • Next, try to pick up the iron filings with the iron nail again. • The magnetised iron nail will be able to attract the iron filings. • The iron nail has now become a magnet.
The electrical method • We can also make magnets using electricity. • Magnets made this way are called electromagnets.
The electrical method • To make an electromagnet, coil an electric wire at least 20 times around a magnetic object such as an iron nail. • Connect the ends of the wire to a battery.
The electrical method • If the iron nail can pick up the same things as a bar magnet, it has now become an electromagnet.
The electrical method • The electromagnet is a magnet only when it is connected to a battery or a source of electricity. • The iron nail loses its magnetism once it is disconnected from the battery (electrical source), and will not be able to attract magnetic objects.
What are the uses of electromagnets? Scrap iron crane Electromagnets are used in our daily lives. Maglev train
What are the uses of electromagnets? Telephone Hospital equipment Can you think of more examples?