demonstrations:creating_an_electromagnet
Creating an Electromagnet
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★★☆ Some safety precautions required to perform safely
Categories: Electricity, Magnetism
Alternative titles:
Summary
Insulated wire is wrapped around an iron nail and connected to a battery to create an electromagnet. Coil count and current are investigated using magnetic strength to pick up paperclips and move compasses.
Procedure
- Gather materials for each pair: an iron or steel nail (about 3 inches), ~2 feet of insulated copper wire (AWG 22 or thinner), a D-cell battery, and several paperclips.
- Strip about ½ inch of insulation from both ends of the wire.
- Tightly wrap the wire around the nail 20 or more times in a single layer without crossing turns, leaving a few inches of free wire at each end.
- Secure each bare wire end to a different terminal of the D-cell (a rubber band or tape can hold them in place).
- Test the electromagnet by attempting to pick up paperclips with the nail’s tip; record how many it lifts.
- Disconnect one lead to conserve the battery, then change one variable at a time: add more coils, use fresh or additional batteries in series, or reverse the battery connections to flip the poles.
- Use a small compass near the coil to map the magnetic field direction; repeat after reversing the battery to observe pole reversal.
- Compare results across groups and discuss which changes increased the magnet’s strength the most.
Links
Creating An Electromagnet - TeachEngineering:
Electromagnet Experiment | Energy | The Good and the Beautiful - The Good and the Beautiful Homeschool Science:
📄 Creating an Electromagnet - ncwit.org: https://www.teachengineering.org/activities/view/cub_mag_lesson2_activity1
Variations
- Swap the iron nail for different cores (steel bolt, large screw, ferrite rod) and compare lifting strength.
- Keep coil count constant but vary battery voltage (single D-cell vs. two or three in series) to see current effects.
- Test different wire gauges (thicker vs. thinner) while holding coil count and voltage constant.
- Build a fixed “field station” coil on a cardboard tube and use a compass to visualize field lines around a solenoid.
Safety Precautions
- Disconnect the battery between trials—continuous current can heat wires and battery terminals.
- Do not short the battery by touching bare wire ends directly together.
- Use only insulated wire; check for damaged insulation before use.
- Handle warm components with care; allow cool-down if parts become hot.
- Keep strong magnets and energized coils away from electronics, magnetic strips, and medical devices.
- Use wire cutters/strippers safely; supervise younger students during tool use.
Questions to Consider
- What creates the magnetic field in your setup? (Electric current in the coiled wire produces the magnetic field.)
- How did increasing the number of coils affect lifting strength? (More coils concentrated the field, increasing strength.)
- What happened when you added more batteries in series? (Higher voltage increased current, strengthening the electromagnet.)
- Why does reversing the battery connections flip the poles? (Current direction reverses, reversing the magnetic field direction.)
- Would the electromagnet work without an iron core? (Yes, the coil alone makes a field, but the iron core concentrates it and makes it stronger.)