"Christian Oersted discovered that electricity traveling through a wire can move the needle of a compass. That means that a wire with electricity running through it is a kind of magnet... an electromagnet."
"Can we make one, huh? Can we? Huh? Huh? Can we? Can we?"
"Oh... okay. And you can make one, too!"
Until Oerstad's discovery in 1820, magnetism and electricity were studied as unrelated phenomena. Actually, magnetic force and electrical force are just different aspects of the same phenomenon: electromagnetism! A wire carrying an electric current is surrounded by a magnetic field just like a permanent magnet. On the other hand, when a wire moves through a magnetic field, an electric current is generated in the wire. In other words, electricity can be used to generate magnetism and magnetism can be used to generate electricity.
An atom is surrounded by electrons which are constantly moving. Since a moving electric charge produces magnetism, an atom is actually a miniature electromagnet!
The great advantage of electromagnets is that you can shut them off. This makes them very useful in moving scrap iron. But electromagnets are also an integral part of such useful devices as electric motors, buzzers and doorbells, solenoid switches, telephones, transformers, and loudspeakers.
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