- Rub a light-weight iron needle with a magnet (always in the same direction) 50 times.
- Stick it through a thin piece of Styrofoam.
- Set the whole business afloat in a bowl of water and observe how try as you might, you cannot prevent the needle from pointing along a north-south axis.
Afterward, the kids built electromagnets. In an electric circuit, the movement of electrons creates a magnetic field, but because it is so weak, you might not notice it. However, if you build a circuit with MANY loops of wire, all in the same direction, each loop reinforces the strength of the magnetic field.