There are several simple methods that can be used to identify the poles of a neodymium magnet.
1. The easiest way is to use another marked magnet. The North pole of the marked magnet will be attracted to the South pole of the magnet to be identified.
2. Hang a string in the middle of the magnet (if the magnet is short, attach an equal number of magnets to both ends of the iron pillar), let the magnet rotate freely, the North pole of the magnet will eventually orient itself towards the North. This actually contradicts the “opposite poles attract” rule of magnetism, (the Earth is also a magnet) but the naming convention of the poles is from ancient times when the pole pointing to the North is called the North pole, the pole pointing to the South is called the South pole.
3. Place the magnet on a piece of foam and drop it into a basin of water, so that the magnet floats on the water, the magnet will rotate freely, gradually the North pole of the magnet will point to the North, and the South pole will point to the South.
4. If you have a compass handy, the needle, which normally points north, will be attracted to the south pole of the neodymium magnet.
5. Use one of the specialized devices.
