How does the compass work? What is the principle of a compass?

Compass. The main component is a magnetic needle mounted on a shaft, which rotates freely under the action of the natural geomagnetic field and remains tangent to the magnetic meridian.

In the direction, the north pole of the magnetic needle points to the north magnetic pole, and the direction can be discerned by using this performance.

The compass is the result of the understanding of magnetism by the ancient Chinese working people in long-term practice. As one of the four great inventions of ancient China.

Its invention has played an immeasurable role in the development of human science and technology and civilization. In ancient China, the compass was first used for rituals, ceremonies, military affairs, divination and feng shui to determine directions.

The application of the compass in navigation to the great geographical discoveries.

and the sea ** has a great promoting effect. The invention of the compass originated from the study of how to orient the problem in ancient China, and it also shows that the ancients attached great importance to the problem of how to orient, for which the compass is known as one of the four great inventions of ancient China. The ancient Chinese used the compass for military and navigational activities, and was also used for Kanyushu, and later introduced to Europe, playing an irreplaceable and important role in European navigation activities and geographical discoveries.

Among the inventions of nautical technology, the compass is also the single most important invention.

The principle of the compass: the two poles of the earth are close to the geographical south pole and the geographic north pole. When the magnet on the earth's surface can rotate freely, it will indicate north and south due to the nature of the magnet that repels the same sex and attracts the opposite sex.

How to use the compass: Place the compass flat on the palm of your hand and the palm of your hand on your chest, without magnetic field interference around it. When the pointer swings stop, look at the pointer, N is north, S is south.

How does the compass work?

1. The substrate refers to the plastic chassis inlaid with a compass pointer.

2. The pointing arrow refers to the arrow on the substrate that indicates the direction, usually in the opposite direction to the person holding the compass.

3. The compass cover refers to the plastic round shell that houses the magnetic needle of the compass.

4. The dial refers to the scale around the compass cover, marking the 360-degree direction, which can be rotated by hand.

5. The magnetic needle refers to the pointer that rotates in the compass cover.

6. The directional arrow refers to the pointer that has no magnetism in the compass cover.

7. The orientation line refers to the line parallel to the navigation arrow in the compass cover.

Principle: The interaction between magnetic poles, the poles of the same name repel each other, and the poles of different names attract each other. The earth itself is a huge magnet, called the geomagnet, the south pole of the geomagnet is near the north pole of geography, and the north pole of the geomagnet is near the south pole of geography, so the small magnetic needle on the earth always guides at one end and points to the north at the other end.

Usage: Put the compass flat, do not interfere with the magnetic field around, wait for the pointer to stop swinging, look at the pointer, the south and north pointing directions are north and south; If n and s are marked, then n is north and s is south.

Features of the compass:

People deduce that the earth has a magnetic field based on the fact that the compass can guide north on the earth's surface, which is called the geomagnetic field. The magnetic field of the earth is very similar to that of a bar magnet.

According to the characteristics of the small magnetic needle n pole pointing northward, people analyze the direction of the geomagnetic field from south to north, which concludes that the n pole of the geomagnetic field is extremely close to the geographic south pole, and the s pole of the geomagnetic field is near the geographic north pole, and the geomagnetic north and south poles are opposite to the geographic north and south poles.

In order to understand this interaction between magnets, the concept of magnetic fields was introduced. A magnetic field is an invisible and intangible substance that exists around a magnet, and the action of this substance is a powerful force on the magnet.

That is to say, one magnet will generate a magnetic field in the surrounding space, and this magnetic field will have a strong effect on the other magnet. If you place a bunch of small magnetic needles around a magnet, then the n-pole of the small magnetic needles will be pointing in the same direction as the magnetic field. That is to say:

Outside the magnet, the magnetic field is directed from the n pole of the magnet to the s pole of the magnet.

How does the compass work:

The red end of the compass now points to the north of the earth. This is because, in accordance with international standards, the red end of the magnetic needle is the north pole of the magnetic needle, which is represented by n (the white end of the magnetic needle is the south pole of the magnetic needle, which is represented by s).

In the compass, the red end n points to the north, because the geographic north pole of the earth is actually the south pole of the earth's magnetic field, so according to the principle of opposites attracting, the north pole of the magnetic needle will be attracted to the south pole of the magnetic field, that is, the north pole direction of geography.

Uses of a compass:

With this performance, you can discern the direction. It is commonly used in navigation, geodesy, travel and military applications. The invention of the compass is the result of the working people of our country who have recognized the magnetism of objects in long-term practice.

As a result of productive labor, people came into contact with magnetite and began to understand the properties of magnetism. The properties of magnet iron were first discovered. Later, the directivity of the magnet was discovered. After many experiments and research, a practical compass was finally invented.

The magnetic needle can rotate freely under the action of the natural geomagnetic field and remain in the tangent direction of the magnetic meridian, and the south pole of the magnetic needle points to the geographic south pole (the north pole of the magnetic field), and the direction can be discerned by using this performance.

The invention of the compass should be the result of slow improvement over a long period of time, and the form of different periods should appear in different forms. During the Tang Dynasty, the activities of the Kanyu family were quite active, and they began to emphasize the choice of direction, and it became a priority to find a more convenient pointer than a magnetic spoon. As a result, the compass iron fish or tadpole-shaped iron pointer and the water floating magnetic needle came into being.

The invention of the compass and the westward spread.

After the advent of the magnetic needle, it was successively used in Kanyu and navigation. In order to be easy to use, easy to read, and the discovery of magnetic declination, higher requirements were put forward for the use of the compass.

However, on some occasions, the water floating magnetic needle in the bowl is still in use, so Shen Kuo's "Mengxi Writings" volume 24 is called "the water floats and shakes". Jiangsu, Hebei and Liaoning Luda have unearthed a special needle bowl for compass without a scale in the Yuan Dynasty. While the ship was still using the floating needle and needle bowl, the compass ran far ahead.

China's magnetic needle and compass have been transmitted westward by land and water, and have had a significant impact on the process of human civilization.

In the past, historians believed that the water compass of the magnetic needle in the water was in the same vein as the compass and was a Chinese invention, but the dry compass was invented in Europe and was only introduced to China by Japanese ships in the 16th century. Now the Linchuan compass proves that the invention right of the dry compass also belongs to China.

1. The earth has a geographical north and south pole and a magnetic north and south pole.

2. Usually we talk about the north and south poles refer to the geographical north and south poles, with the North Star as the standard, pointing to the North Pole at one end of the North Star.

3. The earth is a large magnetic field, that is, the geomagnetic field, and the geomagnetic north and south are opposite to the direction of the geographical north and south (there is actually a little deviation, see "magnetic declination").

4. The compass is based on the principle that the magnetic pole attracts the same sex and repels the opposite sex: the north pole of the compass points to the magnetic south pole (geographic north pole), and the south pole points to the magnetic north pole (geographic south pole).

Is it okay? Please correct.

Magnetism is the repulsion of the same sex and the attraction of the opposite sex. The earth is a magnetic field where the north and south poles exist. The magnetic needle moves in accordance with the magnetic field, so it can point to the north and south poles.

Do you know how this works with a homemade compass?