Take a long strip magnet with known magnetic poles, and based on the principle of repulsion of the same poles and attraction of different poles, it is easy to identify the magnetic poles.
If there are no other magnetic materials such as magnets, if the magnet can float in the water, you can put the magnet in the water. The magnet that rotates freely in the horizontal plane will always have one pole pointing to the south, the other pole pointing to the north, and the one pointing to the south is south pole, the north pole pointing north.
The two ends of the bar magnet have the strongest magnetism and are the two poles. The magnet can be hung with a string. When it is still, one magnetic pole points to the south, the other magnetic pole points to the north, the south pole points to the south, and the north pole points to the north. Read More