Build an electric motor

Overview

In the same way that electrical current creates a magnetic field, the reverse is also true. In this activity, your students will build electric motors that are enabled by magnets. This hands-on experience has real-world application, as all electric motors in our lives come from this basic principle. 

What you'll need

Each group will need:

• Tape
• Large markers
• “Build an electric motor” worksheets for each student
• 120 cm of enameled wire
• Sandpaper
• 2 dry cells (batteries) and holders
• 2 wires with alligator clips
• 1 ceramic magnet
• 2 large paper clips

Instructions

It’s a good idea to build your own electric motor in advance so you know how to do the activity and you can work through the troubleshooting steps.

Safety first

• Ceramic magnets are powerful and can damage electronic equipment. Keep them away from all devices like smartphones, tablets, and computers.
• Metal components in the circuit you are building will get warm during the activity, so don’t touch the batteries, alligator clips, coil, or paper clips.
• Remember to disconnect the wire after each observation.

Building the electric motor

Put your students into groups of two or three and then have them follow the following steps:

1. Students need to create a coil by wrapping the wire tightly around the marker about 20 times; they should have 6 cm of wire sticking out at each end.

2. Then they should loosen the coil slightly and remove it from the marker. To keep the coil from unravelling, have students twist each wire end around one side of the coil. 

3. Students can use sandpaper to scrape away the coating at both ends, exposing about 2 cm of wire.

4. Next, students should bend the paper clips to create holders for the coil. Tape can be used to secure the paper clips to the table, and the ends of the coil should be stuck out through the loops in the paper clips. The paper clip loops must be level so the coil can spin.
5. Students can then connect the alligator clips to the batteries and paper clip holders as shown here. Note that once the clips are connected, electricity is flowing through the circuit. Students may need to help the coil start spinning: 

Troubleshooting the electric motors

If the coil doesn’t spin, here are some things students can try:

• Make sure that the loops of the paper clip holders are level so the coil is balanced and can spin freely.
• The coil needs to be over the magnet for the motor to work properly. Try moving the coil or moving the magnet so the two are lined up.
• Check the circuit’s connections. The paper clips need to be touching the exposed ends of the coil wire or electricity cannot flow.
•  Make sure that the batteries have power in them. Use a light bulb to check.

Document and debrief

Make sure your students make observations on their "Build an electric motor" worksheet and that they complete the analysis.

Have the groups share their experience creating an electric motor. Students can talk about what they found challenging, how they solved problems, and what success looked like.