By Kevin Lee Updated Mar 24, 2022 sirichai_raksue/iStock/GettyImages Electricity and magnetism are distinct entries in the dictionary, yet they are two facets of the same fundamental force. Moving electric charges generate magnetic fields, while varying magnetic fields induce electric currents. A simple current‑carrying wire creates a magnetic field, but when that wire is wound around an iron core, the field becomes substantially stronger. This principle has enabled engineers to build electric motors, generators, MRI scanners, levitating trains, and countless everyday devices that keep our world running.

Electromagnets for Heavy‑Lifting Tasks

Unlike permanent magnets, electromagnets can be switched on and off. They require an external power source and their strength can be adjusted by changing the current. Auto salvage operations routinely use large electromagnets to lift entire cars, reposition them, and then release the load at a new site. Scrap yards employ similar systems to separate ferrous metals from mixed material streams, improving recycling efficiency.

Large‑Scale Electromagnetic Innovations

Japan’s Maglev project uses superconducting electromagnets to propel a train at up to 320 km/h (200 mph), dramatically reducing travel time between major cities. In the United States, the Navy is developing an electromagnetic rail‑gun capable of firing projectiles at speeds exceeding Mach 6, delivering destructive kinetic energy without explosives. The same technology powers electromagnetic catapults that launch aircraft from carrier decks with greater precision than legacy steam systems.

Induction: The Backbone of Modern Electrical Devices

When a wire traverses a changing magnetic field, electric current is induced—a phenomenon known as electromagnetic induction. This principle drives electric motors, power generators, and transformers. Transformers step voltage up or down during transmission, ensuring efficient delivery of electricity to homes and businesses. Motors convert electrical energy into mechanical motion in devices ranging from toy cars and washing machines to Mars rovers. Generators, the reverse of motors, transform mechanical rotation from wind turbines, steam engines, or internal combustion engines into clean electric power.

Hidden Electromagnets in Everyday Electronics

Many consumer devices house small electromagnets that go unnoticed. Press a doorbell button and the resulting magnetic field pulls a striker, ringing the bell. Relays—electromagnetically controlled switches—are found in TVs, computers, cars, elevators, and copy machines, enabling complex control circuits. MRI scanners use powerful superconducting electromagnets to produce detailed images of the human body, a critical tool in modern medicine. From industrial cranes to medical imaging, electromagnets underpin countless technologies that shape our daily lives. Their controllable nature, coupled with the power of induction, makes them indispensable in the modern age.