Your Challenge: Create your own electromagnet!
What You Need
- New D-size battery
- Large iron nail
- About 3 feet of thin-coated copper wire
- Paperclips and other small magnetic objects
- Leaving about 8 inches of wire loose at one end, wrap the rest of the wire around the nail--do not overlap the wire.
- After you finish wrapping the nail, cut the other end the wire so that there is 8 inches loose on that end too.
- Remove about an inch of the plastic coating off both ends of the wire and wrap them around both ends of the battery. (You may want to tape the wire to the battery)
- Be careful! The wire can get very hot.
- Put the point of the nail near the paperclips and watch it pick them up. Voila! An electromagnet.
- When you are done with your electromagnet, disconnect the wires from the battery.
Take It Further
What changes can you make to make this magnet stronger? Try changing the length of wire, the size of the nail, and anything else you can think of to see how your magnet is affected.
How It Works
Electromagnets are temporary magnets. The iron nail only acts as a magnet when electricity is flowing. The electricity flowing through the wire wrapped around the nail rearranges the molecules of the nail so that all the tiny magnetic fields of the individual iron molecules line up in one direction, creating a magnet strong enough to pick up the paperclips!
- The earth has its own magnetic field--that's what makes a compass point north.
- Many scientists believe that birds use the earth's magnetic field to navigate long distances.
- Today's high speed trains use magnets to float slightly above the rails, reducing friction and thus increasing speed.