1. 3.2E Current can produce magnetism pg.88E
Vocabulary
Electromagnetism- Magnetism that results from an electric current.
Electromagnet- Magnet made by placing a piece of iron or steel inside a coil of
wire.
The discovery that an electric current can produce magnetism was made in the
1800’s by Hans Christian Oersted.
He discovered that an electric current produces a magnetic field.
The relationship between electricity and magnetism plays an important role in the
modern technology.
The magnetic field produced as current flows it is represented with circles
around the wire.
An electromagnet can be constructed and the advantage of it is that the
magnetism produced can be controlled, so you can apply it to different
uses.
To make an electromagnet stronger you can:
*Increase intensity of voltage source
*Increase number of loops of wire in the coil
Electromagnets are widely used in many electric devices, including:
-Motors and generators
-Electric bells
-Loudspeakers
-Magnetic recording and data storage:
tape recorders, VCRs, hard disks, credit cards
-Magnetic locks
-Industrial lifting magnets
-Electromagnetic suspension used for MAGLEV trains
2. Because magnetism is a force, magnets can be used to move things.
Electric motors convert the energy of an electric current into motion.
Michael Faraday made the first simple electrical motor in 1821.
Parts of a motor:
*voltage source
*shaft
*commutator
*magnet
*electromagnet
They work like this:
1. Like poles of the magnets push on each other
2. As the motor turns, opposite poles attract
3. The electromagnet’s are switched, and like poles again repel
Electric motors are used in many, if not most, modern machines:
Fans
Blenders
Mixers
Food processor
CD player
Project- Make an electromagnet, 3 member teams, counts as quiz