Chapter 5
MOTORS AND
GENERATORS
What do fans, refrigerators, electric pencil sharpeners, and remote-control toys have in common? They all have motors. Electric motors are machines that change electrical power into motion. This kind of motion, like the spinning blades of a fan, is called mechanical power. And guess what? All electric motors, big and small, use magnets to create that mechanical power. ESSENTIAL QUESTION How do motors and generators use magnets?
If you took apart an electric motor, you’d see magnets inside. Some are permanent magnets, and some are electromagnets. A small motor has two permanent magnets with the opposite poles facing each other. Between those poles is something invisible but strong—a magnetic field.
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