GO IN DEPTH

Electromagnets

Electromagnets

Introduction

Electromagnets come in all sizes, from little ones that make doorbells ring, to enormous magnets that pick up entire cars. There are many uses for electromagnets; cassette players, VCRs, stereo speakers, and televisions are a few of the uses for smaller electromagnets.


Exploration

Explore Using Electromagnets to find out more about how electromagnets are used. Note how electromagnets work in each of these devices:

  • speaker
  • electric bell
  • relay
  • electric motor

Very large electromagnets also are being used in Germany and Japan to lift and drive trains called maglev trains. Maglev trains have no wheels. Instead, they use magnets to run above special rails. The magnets actually lift the train above the rails. Because the train is not actually touching the rails, there is no friction. With no friction, the train runs smoothly and very fast, up to 500 km/h (300 mph).

To find out more about these trains, read How Maglev Trains Work.

 


Knowledge Check

In several paragraphs, summarize some of the uses of electromagnets described in Using Electromagnets. Explain the function of the electromagnet in the devices described. Also, discuss how the electromagnets in these devices are like the one that you built.


This esheet is a part of the Build an Electromagnet lesson.

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Esheet Details

Grades
AAAS