Fun with Magnets

Magnets attract iron, nickel and cobalt objects. The strongest attraction is at the poles (ends). Types: natural magnets (magnetite/lodestone), artificial magnets (bar, horseshoe, ring, electromagnet). A freely suspended magnet always aligns in North-South direction — basis of compass.

Every magnet has two poles: North (N) and South (S). Poles always exist in pairs — cannot separate (break a magnet → two smaller magnets each with N and S). Like poles REPEL (N-N, S-S). Unlike poles ATTRACT (N-S). The pole pointing to Earth's geographic north is called North pole.

A compass contains a small magnetised needle freely pivoting on a pin. The needle aligns with Earth's magnetic field — North pole pointing to Earth's geographic north. Used for navigation for thousands of years. The compass needle is a tiny bar magnet. Earth itself is a giant magnet!

Compasses (navigation), electric motors, generators, speakers, hard drives (magnetic storage), MRI machines in hospitals, scrapyards (magnetic cranes), credit cards (magnetic strip), doorbells, refrigerator door seals. Electromagnets (coil + iron core + current) are used where we need magnetism that can be switched on/off.