Electromagnetism

Electromagnetism is a branch of science that studies how electricity and magnetism are related. It shows that when electric charges move, they create magnetic forces, and when magnetic fields change, they can make electricity flow. This discovery helped humans understand how many modern machines work, from lights and motors to computers and radios.

The connection between electricity and magnetism was first discovered in the 1800s. In 1820, a Danish scientist named Hans Christian Ørsted noticed that a compass needle moved when placed near an electric wire. This meant that electric current could create a magnetic field. Later, scientists such as Michael Faraday and James Clerk Maxwell expanded these ideas. Faraday showed that moving magnets could create electric current — a process called electromagnetic induction. Maxwell combined all these discoveries into one set of laws, known as Maxwell’s equations, which explain how electric and magnetic fields interact.

Electromagnetism is one of the four main forces in nature, along with gravity, the strong force, and the weak force. It affects almost everything we see every day. Electric power plants, for example, use moving magnets and coils of wire to generate electricity. In electric motors, electricity makes magnets spin to power machines. Even light itself is a form of electromagnetic wave that travels through space at incredible speed.

Many everyday objects work because of electromagnetism. Speakers use electromagnets to move air and create sound. Televisions and phones send and receive signals using electromagnetic waves. The magnets in computers help store data, and hospital MRI machines use strong magnetic fields to create pictures inside the body. Without electromagnetism, none of these technologies could exist.

Electromagnets are magnets created by electricity. When an electric current flows through a wire, it makes a magnetic field around it. Wrapping the wire into a coil makes the field stronger, and adding an iron core makes it even more powerful. These electromagnets can be turned on and off easily, which is useful in cranes that lift heavy metal, doorbells, and electric locks.

Electromagnetism helps us understand both natural and man-made systems. It explains why lightning happens, how magnets stick to fridges, and how signals travel through the air. By studying electromagnetism, scientists and engineers continue to create new tools that make life easier, safer, and more connected.