Museum of Science and Industry

Build an Electric Motor

Magnets and electricity work together to make an electric motor.

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Lesson at a glance

How can magnets and electricity work together? Explore the relation between electricity and magnetism by designing an electric motor. How can mechanical energy be generated using magnets and electricity?

Students Will Know:
Electromagnets - Temporary magnets that get their force of attraction from an electric current flowing through a wire. A magnetic field is created when an electric current flows through a wire.
Magnetic field - The area around a magnet where its magnetic force can be detected.
Magnetic poles - The two areas of the magnet where the magnetic force is strongest. Every magnet has a north pole and a south pole. A magnet will push or pull on other magnets - opposite poles attract one another, and the same poles repel one another.

Students Will Be Able To:
Construct a simple electric motor
Identify the variables that may be changed to create a more effective electric motor

Illinois Learning Standards

Late Elementary
State Goal 11: A.2a; A.2b; A.2c; A.2d; A.2e; B.2a; B.2b; B.2c; B.2d; B.2e; B.2f
State Goal 12: C.2a; D.2b
State Goal 13: A.2b; a.2c
Middle / Junior High
State Goal 11: A.3a; A.3b; A.3c; A.3d; A.3e; A.3f; A.3g; B.3a; B.3b; B.3c; B.3d; B.3e; B.3f
State Goal 12: C.3a; D.3a; D.3b
State Goal 13: A.3c

Background information

Electric motors are a perfect way to illustrate the connection between electricity and magnetism. An electric motor changes electrical energy into mechanical energy. Three principles are used to create an electric motor: 1) electric currents produce magnets fields; 2) the direction of the current determines the polarity of the magnetic field that is produced; and 3) opposite magnetic poles attract and like magnetic poles repel.

Guiding questions

Why does the coil spin?
Why does the coil need to be properly balanced?
How can the speed of the motor be increased?
How could you make the coil spin in both directions?
Can you design your motor to cause something else to move?