What is the knowledge of magnets

Magnets can attract iron objects. This property is called magnetism. Generally, the magnetic force of the magnet is fixed (to compare the magnetic force, it can be judged according to the number of paper clips attracted by the magnet.)

1、 Magnet

Magnets can attract iron objects. This property is called magnetism. Generally, the magnetic force of the magnet is fixed (to compare the magnetic force, it can be judged according to the number of paper clips attracted by the magnet.)

2、 Magnet shape

Magnets come in a variety of shapes (U, ring, bar, cylinder, etc.) because they have different uses. Magnets cannot attract copper, aluminum and other metals. (Cobalt and nickel can be attracted)

3、 Properties of magnets

1. The magnet can point to the north-south direction. The magnetic pole of the guide is called South Pole, which is represented by "S"; The magnetic pole pointing to the north is called the North Pole, which is represented by "N".
2. When the poles of two magnets are close to each other, they sometimes attract each other, which is called mutual attraction; Sometimes they push to both sides, which is called mutual exclusion. (We call it like poles repel each other, like poles attract each other)
3. Magnets can also attract iron through some objects. (Iron objects can be separated from other objects by magnet.)
4. The magnetic force of the magnet is strong at both ends and weak in the middle. The part with the strongest magnetic force on the magnet is called the magnetic pole. The magnet has two magnetic poles.
5. When two magnets are pulled together, the magnetic force will increase; When two mutually exclusive magnetic poles are combined, the magnetic force will be reduced.

4、 Application of Magnet -- Compass

1. The compass is an instrument for indicating direction made of the north and south properties of a magnet. The compass is generally composed of a magnetic needle and an azimuth dial. The compass is the result of the understanding of the magnetism of magnets by the working people in ancient China in their long-term practice. More than 2000 years ago, the ancient Chinese made "Sinan".
2. Method of determining direction with compass:
(1) Put the compass box flat and let the magnetic needle rotate freely.
(2) After the magnetic needle stops swinging, rotate the compass box to make the south (S) and north (N) directions marked on the azimuth dial consistent with the south and north directions of the magnetic needle.
(3) Determine each direction against the azimuth wheel.
3. The meaning of the letters on the compass bearing plate: N-North; S-South; W-West; E-East; NE Northeast; SE Southeast; NW Northwest; SW Southwest.
4. The compass can be made of steel needles, iron nails, etc. Rub the pole of the magnet on the steel needle (or iron nail) in one direction for 20 to 30 times. Then mark the north and south poles.
5. Other applications of magnets: The maglev train is suspended by the magnetic force that the magnets repel each other.