## Electromagnets

What is an electromagnet? As its name clearly states, it is a magnet that is made using electricity. A magnetic field is produced when electricity flows through a wire. If we wind wire around a bolt, leaving the ends of the wire unwrapped, and run electricity through the wire by connecting the two unwrapped ends to a source, we can align the mini-magnets in the bolt to produce a magnet. By changing the polarity of the electricity (i.e. changing the direction in which it flows) we change the polarity of the electromagnet. Polarity refers the ends being either North or South, or in the case of a battery, one end positive and the other negative. Small paper clips can be picked up to show that the electromagnet does work.

Troubleshooting:

*If it won't pick up the paper clip:

-Make sure the battery is working.

-Tap the electromagnet on the ground. This helps to align the mini-magnets.

-Make sure the bolt is one that can be magnetized. To test this, see if it is attracted to an existing magnet.

-The wire should be wrapped tightly around the bolt, totaling around 50-60 loops.

-The paper clip may be too heavy. Use a lighter paper clip or break part of it off.

*How can we make the electromagnet stronger?

-By increasing the electricity running through the wire, or the number of loops of wire around the bolt, the strength of the electromagnet is increased.

Warning: The electromagnet gets hot. The more electricity running through, the faster and hotter it gets. A fresh 1.5V is enough to pick up a paperclip. With this battery your electromagnet will get warm after about 5 minutes but won't cause any harm. Hooking up multiple batteries and leaving them connected for a long time could cause trouble, so don't.

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