Homemade Magnet

How Does It Work

What you created using the tightly wound wire around the nail is called a solenoid [sōl-ë-noid]. When an electric current passes through the wire, it creates a magnetic field in the metal core (the nail). When the wire is wrapped around the iron nail and the battery is strong enough, you create a simple electromechanical solenoid. These “electro” magnets are typically weak but are useful over short distances – like picking up paperclips. Electromagnets can, however, be made to become very powerful magnets that have industrial applications.

Science Fair Connection

A Homemade Magnet is a pretty cool activity but it’s not a science fair project. You create a science fair project by identifying and testing variables. A variable is something that might change the outcome. Consider some of the variable options you might test and write up for a science fair project.

• Test a variety of nail sizes or types such as brass, zinc-coated, or glue-coated.
• Change the number of wraps you use on a nail. Record the results in a data table.
• What happens if you use different batteries to make your electromagnet?
• How does the tightness of the wire wraps change the outcome?
• What difference does the thickness (gauge) of the wire make in the effectiveness of your magnet?

These are just a couple of ideas and you certainly aren’t limited to them! Come up with your own variable to test. Remember, you can change only one variable for each test while making sure that all the other factors in your test remain the same!

Safety Information

Be aware that touching a wire to both poles of a battery causes a “short circuit” that quickly drains the battery of its power. The current can also heat up the wire (due to resistance) to the point where it will burn your fingers as you hold it on the poles. It’s possible that the load you put on the wire making the solenoid will reduce the heat produced but be aware of possible injury.