Science Activity: Measuring Magnet Power
Source: Pearson Allyn Bacon Prentice Hall
Topics: Inspiring Your Child's Love of Science, Physical Sciences, Great Science Fair Project Ideas
If you've ever visited a recycling plant, you've probably seen electromagnets. Not only are they much bigger than the horseshoe and bar magnets you've used at school, but they also can be turned on and off! In this activity, you'll make an electromagnet that will let you pick up and drop things.
1. Get Ready
Iron nail (Get this in a hardware store; ask the clerk for help, since most of the nails in the store will be steel.)
Piece of insulated copper wire 20 inches long (about 50 centimeters)
Wire strippers
Dry cell (6 volt)
Small box of paper clips
Graph paper and pencil
2. Do and Wonder
Next you're going to wrap the wire around the nail. First find the midpoint of the wire by folding it in half. Then place the nail at the midpoint, with the wire about halfway down the length of the nail. With each section of wire (that is, above and below the midpoint), make three wraps around the nail. These wrappings or coils should be close together.
Make a small curl at one end of the copper wire, and attach it to one of the terminals on the dry cell.
Put one of the paper clips on the table. Bring the pointed end of the nail near the paper clip. Touch the free end of the copper wire to the other terminal, and hold it there for no more than 2 seconds. What do you observe?
Predict how many paper clips the nail can pick up. Test your hypothesis by touching the free end of the wire to the terminal for just 2 seconds.
Prepare a graph with the labels "Number of Paper Clips" along the vertical axis and "Number of Wire Turns" along the horizontal axis.
Now test your magnet to see how many clips it can pick up. Each time, increase the number of wire turns around the nail.
Make a prediction about the number of clips your magnet will pick up if you add five turns at once. Put an X on your graph at the spot that shows your prediction.
3. Think and Write
Write a short paragraph that tells the results of your experiment.
Explain why an electromagnet is more useful than a permanent magnet.
Explanation
When electricity flows through a wire, the space around the wire starts to act as a magnet. In this activity, you made a temporary magnet. By wrapping the wire around the iron nail more and more times, you increased the power of the electromagnet. The magnet loses its magnetism when the electricity is cut off.
© 2000, Allyn & Bacon, an imprint of Pearson Education Inc. Used by permission. All rights reserved.
Take Action
- this article with friends and family.
- Have a question about Inspiring Your Child's Love of Science? Ask it here.
- Publish your work on education.com.
