Magnetic fields are generated whenever electric charges are in motion. This fundamental concept is a cornerstone of electromagnetism, one of the four fundamental forces of nature.
When an electric charge, such as an electron, moves through space (like in an electric current), it produces a magnetic field around its path. The direction and strength of this field depend on the direction and speed of the charge’s motion. For example, in a wire carrying current, the moving electrons create a circular magnetic field around the wire.
This relationship between electricity and magnetism was formally described by James Clerk Maxwell in the 19th century. His equations showed that electricity and magnetism are deeply interconnected, forming a unified theory known as electromagnetism.
This principle explains how electromagnets work, how electric motors and generators function, and why Earth’s magnetic field is created by the motion of molten iron in its outer core. In essence, magnetism is a dynamic effect of electric charge in motion.