By Jason Thompson Updated Aug 30, 2022

Magnetism is a natural force that enables magnets to interact with other magnets and certain metals from a distance. Each magnet possesses two poles—north and south—whose interactions follow the classic rule: like poles repel, unlike poles attract.

Electricity and Magnetism: An Inseparable Duo

While often treated as separate forces, electricity and magnetism are intimately linked. In the 19th century, physicist Michael Faraday discovered that moving electric charges generate magnetic fields—a principle that underpins both naturally occurring magnets and engineered electromagnets.

Natural Magnets: The Role of Atomic Currents

In naturally occurring magnets, the magnetic field arises from the intrinsic motion of electrons around atomic nuclei. In most materials, the microscopic magnetic moments cancel out, leaving the material nonmagnetic. In certain metals—such as iron, nickel, and cobalt—these moments align, producing a net magnetic field that gives the material its permanent north and south poles.

Electromagnets: Harnessing Current for Magnetic Power

An electromagnet is built from three core components:

• A tightly wound coil of insulated wire.
• A ferromagnetic core, usually iron, which amplifies the field.
• A power source—typically a battery or a DC supply—that drives current through the coil.

When voltage is applied, current flows through the coil, creating a magnetic field. The coil’s geometry directs the field lines, establishing one end as the north pole and the opposite end as the south pole. The iron core further concentrates the field, boosting the magnet’s strength.

Comparing Natural Magnets and Electromagnets

Both natural magnets and electromagnets share common features:

• They each produce a magnetic field and have distinct north and south poles.
• Their fields result from electric currents—microscopic in natural magnets, macroscopic in electromagnets.

However, electromagnets offer unique advantages:

• Variable Strength: By adjusting the current, the magnetic field can be increased or decreased.
• Polarity Control: Reversing the current flips the poles.
• On/Off Capability: Without power, an electromagnet ceases to generate a field.

In contrast, a natural magnet’s strength and polarity are fixed, determined by its material composition and atomic alignment.

Understanding these differences is essential for selecting the right magnetic solution in applications ranging from industrial lifting devices to medical imaging equipment.