Electromagnetism

Electricity and Magnetism have quite a bit in common.  Opposites attracting, likes repelling.  Both have an area around them called a field.  Up until Hans Christian Oersted, these two forces were thought to be similar, but separate.

On April 28, 1820 Hans Christian Oersted made an amazing discovery as he was giving a class lecture (if I could be so lucky!)  He happened to have a compass on the demonstration table he was using for his circuit demonstration.  When he closed the switch, the compass needle moved!  

Electricity produced a magnetic field! Whoa!

Check out the picture from How Stuff Works.

This was the birth of the electromagnet.  Or a magnet you can turn off and on  (I like to picture a big crane lifting cars.)

We build an electromagnet in the lab today and discovered ways to make it stronger.

After experimenting with different variables we found two ways to make it stronger.

There are electromagnets in all kinds of devices, you ipod, buzzers, bells, microphones, even toasters!  Below is an image from Wikimedia.

This bell works using an electromagnet.  The current flows around the upside down u shaped piece of metal.  This makes the u into a magnet.  The u attracts the metal below causing the ball to hit the bell.  When this happens, the circuit is broken and the U is no longer magnetic.  The ball falls.  The circuit is connected again and the whole processes starts again.

The amazing part is that a magnet can also produce electricity!  Double Whoa!

This is how we get electricity today!  

By moving wires or magnets next to each other, a current is produced.  You can use a variety of ways to turn the wire or magnets (wind, water, steam produced by burning fossil fuels.)

Check out this coal generator process from Footprints Science.

Coal generator

Or even build you own!

Build and electromagnet