Build a Simple Electromagnet

An electromagnet converts electrical energy into a magnetic field. When current flows through a coil of wire (a solenoid), it generates a magnetic field along the coil’s axis. Wrapping the coil around an iron core (like a nail) dramatically intensifies the field because iron is a ferromagnetic material. This project demonstrates Oersted’s discovery that electricity and magnetism are linked.

What You’ll Need

• Large iron nail (10–15 cm, thick gauge)
• 1–2 metres of insulated copper wire (enamelled magnet wire or thin flexible wire)
• 1.5 V AA battery (one or two)
• Battery holder or tape to hold wires to battery terminals
• Small metal objects to pick up (paper clips, staples, small screws)
• Wire strippers

Step-by-Step Instructions

1. Prepare the wire: Strip about 3 cm of insulation from each end of the wire. If using enamelled magnet wire, sand the ends with fine sandpaper until bare copper is visible.
2. Wind the coil: Starting about 5 cm from one end of the nail, wind the wire tightly around the nail in neat, close-wound turns. Wind in one direction only. The more turns you wind, the stronger the magnet — aim for at least 50 turns.
3. Secure the winding: Tape the wire at both ends of the coil to stop it unwinding.
4. Connect to battery: Touch the two bare wire ends to the positive and negative terminals of the AA battery. You can use tape or a battery holder clip to hold them in contact.
5. Test the magnet: Hold the nail near a pile of paper clips — it should attract and hold several at once. Release the battery connection and they should fall off (some residual magnetism may remain temporarily).
6. Experiment: Add a second battery in series and count how many paper clips the magnet now holds. Compare with one battery.

Safety Notes

• Do not leave the battery connected for more than 30 seconds at a time — the wire will heat up significantly. Short circuits in this simple setup drain the battery rapidly.
• The nail will get warm — do not leave it connected and unattended.
• Use low-voltage batteries only (1.5–3 V) for safety.

Tips & Troubleshooting

• If the magnet is weak, check that the wire ends are making good contact with the battery terminals.
• Winding more turns in the same direction always increases field strength.
• Try a steel bolt instead of a nail — it may produce a stronger result.