How Do Magnets Work?
Magnets work because of the movement of electrons. In magnetic materials, electrons spin in aligned directions, creating a combined magnetic field. This field extends around the magnet with north and south poles. Opposite poles attract (north-south) and like poles repel (north-north or south-south) because of how their magnetic fields interact.
Key Takeaways
- Every electron acts like a tiny magnet due to its spin and orbital motion around the nucleus.
- Permanent magnets can lose strength if heated above their Curie temperature, which randomizes electron alignment.
- Superconducting magnets at extremely low temperatures create very strong magnetic fields used in MRI machines.
Explanation
Every electron acts like a tiny magnet due to its spin and orbital motion around the nucleus. In most materials, electrons spin in random directions, canceling out. In magnetic materials (iron, nickel, cobalt), electrons can align their spins, creating domains of unified magnetic direction. When these domains align, the material becomes a magnet.
Magnetic fields are invisible lines of force extending from north to south pole. When two magnets approach, their fields interact. Opposite poles have fields that flow together, pulling the magnets toward each other. Same poles have fields that push against each other, creating repulsion. This is why magnets can push or pull without touching.
Electromagnets are created when electric current flows through a wire, generating a magnetic field around it. Coiling the wire concentrates the field. This is how electric motors work - switching the current direction changes the magnetic poles, causing rotation. Earth itself is a giant electromagnet, with its field generated by the molten iron core.
Things to Know
- Permanent magnets can lose strength if heated above their Curie temperature, which randomizes electron alignment.
- Superconducting magnets at extremely low temperatures create very strong magnetic fields used in MRI machines.
- Magnetic monopoles (single north or south poles) have never been observed - breaking a magnet creates two smaller magnets.