What is the difference between permanent magnets and electromagnets?

Permanent magnets and electromagnets are two different types of magnets with different characteristics and uses.

A permanent magnet is made of ferromagnetic materials like iron, nickel, or cobalt, and has a magnetic field that is always present. The magnetic field of a permanent magnet arises due to the motion of electrons within its atoms, which align in a specific way to produce a net magnetic field. Examples of permanent magnets include fridge magnets and those used in electric motors and generators.

An electromagnet, on the other hand, is made of a wire coil that carries an electric current. When the electric current flows through the coil, it creates a magnetic field around it. The strength of the magnetic field can be controlled by varying the current flowing through the wire, which makes electromagnets more versatile than permanent magnets. Electromagnets are used in a wide range of applications, from electric bells and relays to MRI machines and particle accelerators.

In summary, the main difference between permanent magnets and electromagnets is that permanent magnets have a magnetic field that is always present, while electromagnets produce a magnetic field only when an electric current is flowing through them.