What you will need:
- A large iron nail (about 3 inches) or a screwdriver
- A few feet of magnet wire or thin-coated insulated copper wire (you can find this at Radio Shack or a hardware store)
- Scissors to cut the wire
- A piece of sandpaper
- A D-sized battery
- A few pieces of masking, electrical, or other tape
- Some paper clips
Here’s what to do:
- Cut a length of wire (try a foot or two).
- Leaving a few inches of the wire loose at one end, wrap the wire around the iron nail or the screwdriver without overlapping the coils, and then leave another few inches loose at the other end.
- Sand an inch of coating off each end of the wire with sandpaper.
Take it further:
- What do you notice when you bring the nail close to a few paper clips?
- How many paper clips can you pick up?
- Does it matter how many coils you wrap around the nail?
- What happens to the strength of your electromagnet when you add another battery, or use a different size battery?
- What other item can you pick up with your electromagnet?
What’s going on?
When you tape the two ends of the wire to the battery, electricity flows inside the wire and and the wires, battery, and nail will get hot. Disconnect the wires from the battery when it gets warm, and allow the battery to cool before reconnecting. Always disconnect and store the battery separately from other items when you are done with your experiment!
As the electricity flows inside the coiled wire, it induces a magnetic field in the iron core of the nail. You’ve now generated an electromagnet, a magnet that is turned on and off by electricity!