By Dustin Pitan
Updated Mar 24, 2022
Creating magnetic repulsion between a magnet and a metal is a fascinating application of basic physics. A permanent magnet has two distinct poles—north and south. Like poles repel each other, while opposite poles attract. When a piece of metal enters a magnetic field, its internal electrons temporarily align, making the metal behave like a magnet of the opposite polarity. Once the external field is removed, that alignment fades. Therefore, to repel a metal with a magnet, the metal itself must first be magnetized in the opposite direction.
Use a permanent magnet and mark one side with a marker to distinguish the north from the south. Knowing which side is which is essential, though the exact designation is not critical for the repulsion process.
Place the metal close to the magnet. If it is a ferromagnetic material—such as iron, nickel, or cobalt—it will be drawn toward the magnet. Non‑magnetic metals like aluminum or copper will not respond.
Take the magnet and rub it over the metal in a single direction repeatedly. Consistent, unidirectional strokes align the magnetic domains within the metal, giving it a temporary north or south polarity. The more strokes, the longer the induced magnetism persists, as the domains remain aligned for an extended period.
Withdraw the magnet, flip it so that the opposite pole faces the now‑magnetized metal, and bring it close again. Because the metal’s induced polarity is opposite to the magnet’s, the force between them will be repulsive.
By rubbing a permanent magnet over a ferromagnetic metal, you can temporarily magnetize the metal. Flipping the magnet so that its opposite pole faces the metal then produces magnetic repulsion. For a more durable solution, you can create an electromagnet by winding wire around the metal and connecting it to a power source.
