Electromagnets are magnets that work only when electric current flows through them, and they lose their magnetism when the current is switched off. They are made by winding coils of wireā€”often around an iron coreā€”so that the electric current in the coil creates a controllable magnetic field.

What are electromagnets?

An electromagnet is a type of magnet whose magnetic field is produced by electricity rather than being permanently ā€œbuilt inā€ to the material. This means it acts like a magnet only while current is flowing, making it a temporary magnet that can be turned on and off.

Key features

  • A coil of conductive wire (usually copper) is wrapped into many turns, often around an iron or steel core.
  • When current flows through the coil, a magnetic field forms along the center of the coil and around it, giving the electromagnet north and south poles like an ordinary magnet.
  • When the current is stopped, the magnetic field largely disappears and the core usually loses most or all of its magnetism.

How do electromagnets work?

Electromagnets rely on the fact that electric current in a wire creates a magnetic field around that wire, a principle summarized by Ampereā€™s law in electromagnetism. By winding the wire into many loops, these small fields add together and concentrate inside the coil, making the field much stronger.

Step-by-step idea

  1. Electric charges move through the coil when it is connected to a power source.
  2. Each loop of current produces a circular magnetic field, and the fields from many loops combine.
  1. A ferromagnetic core (like iron) inside the coil becomes magnetized as its internal domains align with the coilā€™s field, further boosting the overall field strength.

What affects their strength?

Several factors control how strong an electromagnet can become, which is why engineers adjust these when designing devices.

  • Number of turns of wire: More turns around the core usually increase the magnetic field for the same current.
  • Current size: A higher current in the coil leads to a stronger magnetic field, up to material and heating limits.
  • Core material: Soft iron or similar ferromagnetic materials focus magnetic flux and give a much stronger field than air alone.
  • Geometry: The shape of the core and coil (long solenoids, C- or U-shaped cores, flat-faced types) can concentrate the field where it is needed.

Where are electromagnets used?

Electromagnets show up in a huge range of modern technology because their magnetism is controllable and can be made very strong.

  • Electric motors and generators: Coils and electromagnets convert between electrical and mechanical energy in everything from fans to power plants.
  • MRI machines: Powerful superconducting electromagnets create intense, stable fields used for medical imaging.
  • Relays, solenoids, and bells: Small electromagnets move metal parts to switch circuits, pull plungers, or ring bells.
  • Industrial lifting magnets: Large electromagnets lift and drop heavy scrap metal in recycling yards and steelworks.

Why theyā€™re important today

Because their strength and timing can be controlled electronically, electromagnets are central to modern power systems, electronics, and medical devices. As newer fields like magnetic levitation transport and advanced particle accelerators develop, improved electromagnet designs continue to be an active engineering and research topic.

TL;DR: Electromagnets are coils of wire (usually around an iron core) that become magnetic only when electric current flows, letting engineers turn strong magnetism on and off for use in motors, MRI scanners, relays, and heavy lifting equipment.

Information gathered from public forums or data available on the internet and portrayed here.