Fremont Magnet Elementary

Electromagnets

Standards:
c. Students know electric currents produce magnetic fields and know how to build a simple electromagnet.

d. Students know the role of electromagnets in the construction of electric motors, electric generators, and simple devices, such as doorbells and earphones.

e. Students know electrically charged objects attract or repel each other.

1. Magnets Review

Last week you learned that magnets have north and south poles. Like poles repel and unlike poles attract. You also learned that the Earth has a magnetic field.

Click here and take the test at the bottom of the page

2. What is an electromagnet?

You know what a magnet is, but what is an electromagnet? Look at the first part of the word - electro. What do you think that might mean?

An electromagnet works with electricity. They are temporary magnets that only work when electricity goes through the coil of wire. When the power is on, it is magnetized. When the power is off it is not magnetized.

Picture is from UIUC Physics Dept.

3. What's the difference between a regular magnet and an electromagnet?

The magnetic force in a magnet is always there. The magnetic force field of an electromagnet can be turned off and on by using a switch. When electricity is turned on, the magnetic force is on. When electricity is turned off, the magnetic force is turned off.

Click here to watch a BrainPop movie about electromagnets.

4. How do they work?

Click here to find out how they work and how you make an electromagnet stronger.

To experiment with the different variables, use this link and click on ELECTROMAGNETS on the left side of the screen.

To see an movie of different ways to make an electromagnet stronger, click here.

5. Magnets and Electricity

One of the interesting things about magnetism is that is that it is closely related to electricity. You know that you can make a magnet by using electricity, but did you know that you can make electricity with a magnet?

If you move a magnet through a coil of wires, it an electric charge in the wire. That is called a generator.

6. How are they used?

Every time you ring a doorbell or listen to music through speakers you use an electromagnet. Click here to see how a doorbell works.

Electromagnets are used to make things more and turn things off and on. Experiment with different electromagnets that you find in the kitchen by clicking this link and choosing Kitchen Magnets

Click on the School for Champions link to learn more.

How Stuff Works

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