By John Papiewski
Updated Mar 24, 2022

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We’re all familiar with the magnets that stick to refrigerators and the toys we play with. Those are permanent magnets—they retain their magnetic pull for years. Electromagnets, on the other hand, become magnetic only when electricity runs through them. When the power is turned off, the magnetism disappears. Electromagnets are everywhere, from household appliances to industrial machines, and you can even build a simple one at home.

Parts of an Electromagnet

A basic electromagnet is made of three essential components:

• An iron core—commonly a bolt or nail
• A coil of insulated copper wire wrapped around the core
• A source of electricity, such as a 6‑ or 9‑volt battery

When the battery is connected, electric current flows through the wire coil, creating a magnetic field that magnetizes the iron core.

What Electromagnets Do

With the battery connected, the ends of the iron core become powerful magnets capable of lifting small pieces of iron or steel. Disconnect the battery, and the magnetic field collapses, letting the metal fall away. The key advantage of an electromagnet over a permanent one is the ability to turn it on and off at will.

Things That Have Electromagnets

Many everyday devices contain hidden electromagnets:

• A car’s electronic door lock uses an electromagnet to open the latch.
• A radio speaker’s electromagnet moves the cone to produce sound.
• Electric motors in toys and appliances rely on electromagnets to create motion.
• Large‑scale applications, like scrapyard cranes, use powerful electromagnets to lift entire cars.

Make Your Own Electromagnet

Here’s a simple experiment you can try:

1. Gather a 6‑ or 9‑volt battery, 10 feet (or more) of insulated copper wire, and an iron bolt or nail.
2. Wrap the wire tightly and evenly around the middle of the bolt, leaving about an inch of the bolt ends exposed.
3. Strip about 1/2 inch of insulation from each end of the wire using a wire stripper or hobby knife.
4. Connect the bare copper ends to the battery terminals.
5. Observe how the bolt picks up small metal objects—staples, iron filings, or a thin metal plate.
6. Feel the wire’s surface; if it becomes hot, disconnect the battery immediately and allow the coil to cool.

This hands‑on activity demonstrates the principles of electromagnetism and the safety considerations when working with electric current.