The magnetic force of the permanent magnet will not be exhausted. Non-permanent magnets will run out of magnetic force.
Magnets can be divided into "permanent magnets" and "non-permanent magnets". Permanent magnets can be natural products, also known as natural magnets, or artificial. Non-permanent magnets, such as electromagnets, are magnetic only under certain conditions.
The extended data magnet is composed of iron, cobalt, nickel and other atoms, with special internal structure and its own magnetic moment. Magnets can generate magnetic fields and attract ferromagnetic substances, such as iron, nickel, cobalt and other metals.
Types of magnets: shape magnets: square magnets, ceramic tile magnets, irregular magnets, cylindrical magnets, circular magnets, disc magnets, bar magnets, magnetic frame magnets, nature magnets: samarium cobalt magnets, neodymium magnets (strong magnets), ferrite magnets, Al-Ni-Co magnets, Fe-Cr-Co magnets, industrial magnets: magnetic elements, motor magnets, rubber magnets, plastic magnets.
Magnets are divided into permanent magnets and soft magnets. Permanent magnets strengthen magnetism, so that the spin of magnetic substances and the angular momentum of electrons are arranged in a fixed direction, while soft magnets are electrified. (It is also a method of magnetizing. ) Soft iron will slowly lose its magnetism after being removed by equal current.
Hang the midpoint of the bar magnet with a thin wire. When it is at rest, its two ends will point to the south and north of the earth respectively. One end pointing to the north is called North Pole or N Pole, and the other end pointing to the south is called Guiding Pole or S Pole.
If you think of the earth as a big magnet, the geomagnetic north pole of the earth is the guiding pole, and the geomagnetic south pole refers to the north pole. Between magnets, magnetic poles with the same name repel each other and magnetic poles with different names attract each other. So the compass repels the south pole, the north arrow repels the north pole, and the compass attracts the north arrow.
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