Make an Electrical Generator

Posted on September 6th, 2012

Electricity might seem scary, but it’s really very simple. You can get a magnet to make electricity with just a few coils of wire. Try using different magnet strengths, moving the magnet more quickly, or using a different number of wire loops to see how these factors change the amount of energy you make.

What you’ll need:

  • Wire cutters
  • Tape measure
  • Two 7 meter pieces of insulated 0.81 mm wire
  • Big glass jar
  • Small glass jar
  • Sticky tape
  • Modeling clay
  • Compass
  • Small bar magnet


1. Get a parent or teacher to strip the insulation off of about 10 cm of each piece of wire, starting at the ends.

2. Wrap one of the wires around the mouth of the big glass jar. Twist the wire around itself to keep it from unwinding. Leave about 45 cm free at each end of the piece of wire. Use sticky tape to keep the wire coil from slipping off of the jar.

3. Wrap the second wire around the mouth of the small glass jar. Twist it and secure it with tape just like the other piece.

4. Lay the big jar on its side at one end of a wooden table. A metal table will not work correctly.

5. Twist the bare ends of the wire from one jar around the bare ends of the wire on the other jar.

6. Use a little bit of modeling clay to stick the compass into the mouth of the big jar.

7. Turn the jar so that the wire coils wrapped around it line up with the needle of the compass. Use a piece of modeling clay to stick the jar to the table so that it stays in that position.

8. Put the small jar right side up on the table, but as far away from the big jar as possible.

9. Take the magnet and move it in and out of the small jar. You should see the compass needle move!

What’s Happening?

When you move the magnet inside the wire coils that are wrapped around the mouth of the small jar, you’re making an electric current. This current moves through the wire one way when you push the magnet into the coils, then reverses itself when you pull the magnet out. This type of electricity is referred to as alternating current and is similar to the electricity in a wall socket. Big generators at power plants work a lot like this small one.

The compass needle moves because the wire makes a magnetic field when it has electricity in it. This influences the compass, moving it away from true north. Since the current is alternating, the needle moves back and forth as it changes direction.

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