Make a magnet that turns on and off with electricity

Suitable for kids aged 6+

CAUTION: Do not hold the wire on the battery for long periods without removing it. The wire and/or the battery terminal may get hot. The nail is sharp, handle with care.

You Need:

  • Large nail
  • Plastic coated wire (stripped of the plastic at each end)
  • Battery
  • Washer or paper clip (any metal object containing iron will work)

What to do:

  1. Wind the plastic coated wire tightly around the nail about 40 times - more turns makes a stronger magnet. It doesn't matter if the wire turns overlap.
  2. Hold one end of the stripped wire to one end of the battery (terminal), and the other end of the stripped wire to the other battery terminal.
  3. With the wire connected to the battery, pick up your metal object (washer or paper clip) with the sharp end of your new electromagnet.
  4. To turn off the magnetism, break the circuit by removing the wire from the end of the battery.
  5. Can you think of a way to hold the wires onto the battery without using your fingers - masking tape and paper clips might get you started?
  6. As a further project you might like to use things around your house to design a base and mount to hold the nail and battery in place. Make sure you get your parents to help.

Why is it so?

Magnetism and electricity are closely related. When the electric current flows near the nail, all the mixed up magnetic domains in the steel nail line up like little soldiers and point in the same direction. The magnetism in the lined up domains adds-up to make a strong magnetic field. When the electricity stops flowing the domains go back to pointing in random directions and the magnetism is lost. Electromagnets are used in real life all the time, in 'tube-type' televisions, in loudspeakers, in some door bells and in scrap metal yards.