21 Jul

Electromagnetic Motor!

homopolar motor1So, it’s hot, and you are bored at home, or in need of a science fair idea, but you only have a battery, a magnet, some copper wire, pliers, and wire cutters.  Well, that’s enough to make a simple homopolar motor.  A homopolar motor is a simple motor which uses a electromagnetic field to work.  It was invented in 1821 by Michael Faraday (if you have never heard this name, look him up…he did some really impressive things!).  This project is safe, fun, and easy to make…it will definitely impress your family and friends.
What you need:  You only need five things – a battery, a magnet, some copper wire, some wire cutters, and pliers to shape the wire.

homopolar motor2What to do:  Cut a length of wire and use the pliers or your hands to shape it in various ways.  Be creative.  After you try your shape out, you can alter it, and try again to see what shapes work better than others.  It is good to have some type of central point in the shape that you can align with the top of the battery, and to make sure that the shape is long enough to reach down to the magnet.  Now, center the battery on the magnet (the negative pole of the battery should rest on top of the magnet).  Balance the copper wire shape on top of the battery.  Make small changes in the shape until it spins freely.  Feel free to develop the experiment by changing the size of the battery, the magnet, and/or the copper wire.  See what shapes spin fastest.  If you need some help, or just want to see the motor in action, check out this YouTube Video put together by Nham Tran, a U.T. Arlington undergraduate chemistry major, who submitted this project to be featured by DISCUS.

How does it work?  One word – electromagnetism.  In this experiment, the battery provides the electircal current and the magnetic provides the magnetic field.  The combined current and magnetic field creates an electromagnetic force.  When the wire is balanced on the battery, the current travels into the wire and down to the magnet.  The electromagnetic force generated causes the wire to spin.  It will spin indefinitely, until the battery dies.

Have fun and tell us how it worked for you!


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