By Isaiah David Updated Mar 24, 2022
Every time electric current passes through a conductor, it generates a magnetic field. While a single wire produces a relatively weak field, arranging the wire into a coil concentrates the magnetic flux, producing a far stronger magnet.
Select a cylindrical iron core—such as a nail or a steel rod—to concentrate the magnetic field. Air‑core coils are used in high‑frequency circuits, but for a powerful electromagnet, an iron core is essential.
Using 22‑gauge magnet wire, wind the coil tightly around the core. Leave roughly 6 inches of wire free at each end. The tighter the turns, the stronger the magnetic field.
Affix the winding to the core with tape or epoxy. Once secured, cut the extra wire off the spool, leaving the free ends intact.
Remove the enamel coating from each end by briefly heating with a lighter or match, then wiping clean with a cloth. This exposes the conductive copper.
Attach the stripped ends to a DC source—e.g., a 1.5 V lantern battery. When powered, the coil will attract small ferromagnetic objects such as paper clips.
To strip the enamel, you can also use nail polish remover or scrape it with a craft knife.
