Define Magnetism

Magnetism is the invisible force exerted by magnetized materials. This phenomenon occurs when stable electrons in the atoms of certain substances are influenced to align in response to an external magnetic field. This force can originate from either a permanent magnet or an electric current. While all materials can be affected by magnetic forces, ferrous materials exhibit strong magnetism, whereas most other substances are only weakly magnetic.

Typically, any magnetized material will possess both a North Pole and a South Pole, with the magnetic field flowing from the South Pole to the North Pole through the magnet itself and returning to the South Pole via the surrounding air. Two magnets will attract each other when their opposite poles are facing, while like poles will repel one another. Everyday experiences of magnetism usually involve ferromagnetic metals such as iron, cobalt, or nickel, while permanent magnets made from rare earth materials generate powerful magnetic fields.

Additionally, magnetic phenomena can arise from electromagnetic fields. Most ferromagnetic materials retain their magnetism under normal conditions. In contrast, electromagnets generate a magnetic field through wire coils that are energized by an electric current. When conductive wire is tightly wound around a metal core, that core becomes a powerful magnet for as long as the current flows. Once the current ceases, the magnetic field dissipates. Unlike permanent magnets, electromagnets can be switched on and off as needed.