How to Create an Electromagnet Using Iron

Electric currents create magnetic fields. You can build up a magnetic field, folding it over on itself repeatedly, by coiling up the current-carrying wire. The coil alone can serve as an electromagnet. By putting a rod of magnetizable material such as iron in the length inside the coil, you can increase the magnetic field strength several times more. Steel, made mostly of iron, has the same effect.

Things You'll Need

• Iron (steel) bolt
• Thin insulated copper wire
• 9V battery
• Electrical tape

Instructions

1. Wind thin, insulated copper wire dozens of times around an iron bolt. Overlapping the wire is fine. The thinness of the wire allows a higher number of coils.

2. Scrape the insulation off the two ends of the wire using scissors or a knife.

3. Attach the bare wire ends to the two terminals of a 9V battery with electrical tape. The iron bolt will now function as a magnet. You can demonstrate this by picking up paper clips.

Tips & Warnings

• The more times you wind the wire around the iron bolt, the stronger the electromagnet will be.

• Increasing the current--by increasing the voltage--will also make the electromagnet stronger. You can do this by connecting 9V batteries in a series, negative to positive, either with wires in between or by snapping together the terminals directly.

References

• "Fundamentals of Physics;" David Halliday and Robert Resnick; 1991
• Georgia State University