Electromagnet
A coil of wire with a current flowing makes a magnetic field like a bar magnet. Adding an iron core, more turns, or a bigger current makes it stronger. It switches off when the current stops.
Last updated
Analogy
A magnet with an on-off switch.
In practice
Scrapyard cranes use big electromagnets to lift cars, then drop them by turning the current off.
Practice
Flashcards
- Name three ways to strengthen an electromagnet.More coil turns, bigger current, an iron core.
Questions people ask
How can I make an electromagnet stronger?
Wrap more turns of wire around the core, increase the current, or put a soft iron core inside the coil. Each change strengthens the magnetic field. Soft iron is used because it magnetises easily and loses its magnetism as soon as the current is switched off.
What is the advantage of an electromagnet over a permanent magnet?
An electromagnet can be switched on and off, and its strength can be changed by altering the current. A permanent magnet is always on. That control is why electromagnets are used in cranes, doorbells, relays and electric locks, where a quick on-off switch matters.