Why do magnets have two poles? How to determine the south pole and north pole of an electromagnet

Magnets are something that we remember deeply when we were young. They are magical things. Have you ever wondered why a magnet can attract a piece of iron, while another magnet can push it away? This is because magnets have a magical force called magnetic force. Why do magnets have two poles? Is it worth our study and thinking?

Contents of this article

1. Why do magnets have two poles?

2. How to determine the south pole and north pole of an electromagnet

3. Do magnets always have magnetism?

Why do magnets have two poles?

The magnetic field is generated by electron spin. Each atom is a small magnet. In most materials, the magnetic field points in a disordered manner and is offset. In a magnet, the magnetic field points in one direction, and this direction attracts the opposite direction, so there are two poles. The part with the strongest magnetic force on a magnet is called a magnetic pole. A magnet has two magnetic poles. When two magnetic poles are close, they sometimes repel each other and sometimes attract each other. The action between the magnetic poles is mutual. There are both magnetic force and intermolecular force between magnet molecules. The intermolecular force is much greater than the magnetic force. When the distance between magnet molecules increases, the intermolecular force decreases to disappear, and the magnetic force will be manifested.

How to determine the south and north poles of an electromagnet

1. Use a known magnet to determine the magnet based on the fact that like poles attract and unlike poles repel. Place one end of the magnet close to the south pole of the known magnet. If they attract, it is the north pole, and the other end is the south pole.

2. Find a compass. When the compass is stable, take one pole of a magnet and bring it close to the N pole of the compass. If they repel each other, it is the North Pole. If they attract each other, it is the South Pole.

3. Use geographic magnetic poles to determine. For example, for a bar magnet, you can use a wire to tie the middle of the magnet and hang it up. When the magnet is nearly horizontal and still, the end pointing to the north is the N pole, and the end pointing to the south is the S pole.

4. Use the right-hand rule. Hold the electromagnet with four fingers except the thumb in the direction of the current, and the direction of the thumb is the North Pole.

Are magnets always magnetic?

A magnet is an object that can generate a magnetic field. It is a magnetic dipole that can attract ferromagnetic materials such as iron, nickel, cobalt and other metals. The determination of magnetic poles is to suspend a magnet with a thin wire. The magnetic pole pointing to the north is called the North Pole or N Pole, and the magnetic pole pointing to the south is called the South Pole or S Pole. (If you think of the earth as a big magnet, the current geomagnetic north pole of the earth is the N Pole, and the geomagnetic south pole is the S Pole.) Magnets with opposite poles attract each other, and with the same poles repel each other. The South Pole attracts the North Pole, the South Pole repels the South Pole, and the North Pole repels the North Pole.