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Mini-Quiz: Electromagnetic Devices

by Ron Kurtus (revised 10 March 2012)

Take this Mini-Quiz to check your understanding of the lesson material.

1. How is the magnetic field made to vary in a loudspeaker?

A varying electrical signal changes the strength of the electromagnet

Sound from the loudspeaker created a varying magnetic field

Radio waves move the speaker cone

2. Why is an electromagnet good for picking up and dropping things?

It attracts aluminum and other metals

Once an object is picked up, it become magnetized and is repelled

The electromagnetic field can easily be turned off and on

3. What is big advantage of a maglev train?

It can move at the speed of light

There is no friction from wheels on a track

The train never stops moving

If you got all three correct, you are on your way to becoming a Champion in Physics. If you had problems, you had better look over the material again.

Use your imagination to create new applications

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