A. Magnets
Magnets can attract objects made of iron, a property called magnetism. Generally, the magnitude of the magnetic force of a magnet is fixed (to compare the magnitude of the magnetic force, you can judge the magnet by the number of paper clips it attracts).
Second, the shape of magnets
Magnets come in a variety of shapes (U-shaped, ring-shaped, bar-shaped, cylindrical, etc.) because they have different uses. Magnets cannot attract metals such as copper and aluminum. (Cobalt-nickel can be attracted)
3. Properties of magnets
1. Magnets can point in a north-south direction. The magnetic pole of the guide is called the South Pole, indicated by "S"; the magnetic pole of the North Pole is called the North Pole, indicated by "N".
2. When the poles of two magnets are close to each other, sometimes they will be sucked to a piece, called mutual attraction; sometimes they will be pushed to both sides, called mutual repulsion. (We call the same poles repel and opposite poles attract.)
3. Magnets can also attract iron across some objects. (Separation of ferrous objects from other objects can be done by magnet sucking ferrous objects.)
4. Magnet magnetic force is strong at both ends and weak in the middle, the strongest part of magnet on the magnet is called magnetic pole, magnet has two magnetic poles.
5. When two magnets are attracted together, the magnetic force increases; when two mutually exclusive poles are combined, the magnetic force decreases.
Fourth, the application of magnets - compass
1. Compass is the use of magnets can point to the nature of the north and south made to indicate the direction of the instrument. General compass is composed of a magnetic needle and azimuth disk. Compass is the ancient Chinese working people in the long-term practice of the magnet's magnetic understanding of the results. 2000 years ago, China's ancient people made "Sinan".
2. Using the compass to set the direction of the method:
(1) put the compass box flat, let the magnetic needle free rotation.
(2) After the magnetic needle stops swinging, rotate the compass case so that the south (S) and north (N) directions marked on the azimuth disk are the same as the south and north directions pointed by the magnetic needle.
(3) Determine each direction against the azimuth disk.
3. The meanings of the letters on the compass bearing disk: N-North; S-South; W-West; E-East; NE-Northeast; SE-Southeast; NW-Northwest; SW-Southwest.
4. To make a compass you can use things such as a steel pin and an iron nail. Use the pole of a magnet to rub on a steel needle (or iron nail) in one direction and do it 20 to 30 times repeatedly. Then mark the south and north poles.
5. Other applications of magnets: Maglev trains are suspended using the magnetic force of repulsive magnet poles.
2. Knowledge about magnets
Magnets are composed of atoms of iron, cobalt, nickel, etc., whose atoms have a special internal structure and have a magnetic moment of their own. Magnets are capable of generating magnetic fields and have the property of attracting ferromagnetic substances such as iron, nickel, cobalt and other metals.
Types of magnets
1, shape class magnets. Square magnets, tile magnets, shaped magnets, cylindrical magnets, ring magnets, round sheet magnets, magnetic bar magnets, magnetic frame magnets.
2. Property class magnets. Samarium cobalt magnets, neodymium iron boron magnets (powerful magnets), ferrite magnets, alnico magnets, ferrochrome cobalt magnets.
3, industry magnets: magnetic components, motor magnets, rubber magnets, plastic magnets and other types.
4, the magnet is divided into permanent magnets and soft magnets, permanent magnets are coupled with strong magnetism, so that the spin of the magnetic material and the electron angular momentum into a fixed direction of the arrangement of soft magnets is coupled with electricity.
Expanded information:
The discovery of magnets.
Magnets are naturally occurring magnetite. The ancient Greeks and Chinese discovered a naturally magnetized stone in nature and called it "magnetite". This stone could magically pick up small pieces of iron and always point in the same direction after swinging at random.
Early mariners used this magnet as their earliest compass to find their way at sea. It was the Chinese who first discovered and used magnets to make the "compass", one of the Four Great Chinese Inventions.
After thousands of years of development, magnets have become a powerful material in our lives. By synthesizing alloys of different materials, it is possible to achieve the same effect as a magnet, but also to increase the magnetic force. Man-made magnets appeared in the 18th century, but the process of creating stronger magnetic materials was slow until the 1920s when aluminum nickel cobalt (Alnico) was created.
Baidu Encyclopedia-Magnets
3. Knowledge about magnets, how much do you know
Magnetic properties of magnets
Magnets are able to generate a magnetic field that attracts ferromagnetic substances such as iron, nickel, cobalt and other metals. The midpoint of a bar magnet is suspended by a thin wire, and when it is at rest, each of its two ends will point to the south and north of the Earth; the end pointing north is called the north pole or N pole, and the end pointing south is the south pole or S pole. If you think of the Earth as a large magnet, the Earth's geomagnetic north pole is currently the south pole and the geomagnetic south pole is the north pole. Magnet to magnet, same poles repel and opposite poles attract. Therefore, the compass and the South Pole repel, the North Pointer and the North Pole repel, while the compass and the North Pointer attract.
Classification of magnets
Magnets can be categorized as "permanent" and "non-permanent". Permanent magnets can be natural products, also known as natural magnets, or man-made (the strongest magnets are neodymium-iron-boron (NdFeB) magnets). [1] Non-permanent magnets, such as electromagnets, are magnetic only under certain conditions.
Magnets were not invented by man, they are natural magnetite. The ancient Greeks and Chinese discovered a naturally magnetized stone in nature and called it "magnetite". This stone could magically pick up small pieces of iron and always point in the same direction when swung at random. Early mariners used this magnet as their earliest compass to find their way at sea. The earliest discovery and use of magnets should be the Chinese, also known as the "compass", is one of the four great inventions of China.
After thousands of years of development, magnets have become a powerful material in our lives. By synthesizing alloys of different materials, it is possible to achieve the same effect as the magnet, but also to increase the magnetic force. Man-made magnets appeared in the 18th century, but the process of making stronger magnetic materials was slow until the 1920s when Alnico (aluminum nickel cobalt) was made. This was followed by ferrite in the 1950s and rare earth magnets [Rare Earth mag including NdFeB and SmCo] in the 1970s. Since then, magnetic science and technology has developed rapidly, and strong magnetic materials have made components more miniaturized.
4. How much do you know about magnets
Magnetic properties of magnets Magnets are able to generate a magnetic field that attracts ferromagnetic substances such as iron, nickel, cobalt, and other metals.
The midpoint of a bar magnet is suspended by a thin wire, and when it is stationary, each of its two ends will point to the south and north of the Earth, with the end pointing to the north known as the North Pole or N Pole, and the end pointing to the south known as the South Pole or S Pole. If you think of the Earth as a large magnet, the Earth's geomagnetic north pole is currently the south pole and the geomagnetic south pole is the north pole.
Between magnets, same poles repel and opposite poles attract. So, a compass repels the South Pole, a compass repels the North Pole, and a compass attracts the North Pole.
Classification of magnets Magnets can be divided into "permanent magnets" and "non-permanent magnets". Permanent magnets can be natural products, also known as natural magnets, or man-made (the strongest magnets are neodymium-iron-boron magnets).
[1]Non-permanent magnets, such as electromagnets, are magnetic only under certain conditions. Magnets were not invented by man, they are natural magnetite.
The ancient Greeks and Chinese discovered a naturally magnetized stone in nature, which they called "magnetite". This stone could magically pick up small pieces of iron and always point in the same direction when swung around.
Early mariners used this magnet as their earliest compass to find their way at sea. It was the Chinese who first discovered and used the magnet, or "compass", one of the four great Chinese inventions.
After thousands of years of development, magnets have become a powerful material in our lives. By synthesizing alloys of different materials, you can achieve the same effect as a magnet, but also increase the magnetic force.
Man-made magnets appeared in the 18th century, but the process of making stronger magnetic materials was slow until the 1920s, when aluminum-nickel-cobalt (Alnico) was made. Then, in the 1950s, ferrite was created, and in the 1970s, rare earth magnets [Rare Earth mag including neodymium-iron-boron (NdFeB) and samarium cobalt (SmCo)] were created.
Since then, the technology of magnetism has developed rapidly, and strong magnetic materials have made components more miniaturized. Modern developments In 1822, the French physicists Arago and Lussac discovered that when an electric current passes through a winding in which there is a piece of iron, it magnetizes the iron in the winding.
This is actually the original discovery of the principle of electromagnet. 1823, Sturgeon also did a similar experiment: he is not a magnet on a U-shaped iron bar around 18 turns of bare copper wire, when the copper wire and voltaic batteries connected to the copper coils around the U-shaped iron bar on the copper coils that produce a dense magnetic field, which makes the U-shaped iron bar into a piece of "electromagnet". ".
This electromagnet on the magnetic energy than the permanent magnet can amplify many times, it can suck up more than it is 20 times heavier than the iron, and when the power cut off, the U-shaped iron bar on what the iron can not absorb, and re-become an ordinary iron bar. Sturgeon's invention of the electromagnet, so that people see the bright prospects for the conversion of electrical energy into magnetic energy, this invention soon spread in the United Kingdom, the United States and some coastal countries in Western Europe.
In 1829, the American electrologist Henry Sturgeon electromagnet device made some innovations, insulated wires instead of bare copper wires, so do not have to worry about being too close to the copper wire and short circuit. As the wires have an insulating layer, they can be tightly wound together in a circle, because the denser the coil, the stronger the magnetic field generated, which greatly improves the ability to convert electrical energy into magnetic energy.
By 1831, Henry had tried out a newer electromagnet, and although it was not very large, it was able to suck up a 1-ton block of iron. The invention of the electromagnet also led to a significant increase in the power of the dynamo.
5. Information about magnets
Magnet components are iron, cobalt, nickel and other atomic structure is special, the atoms themselves have a magnetic moment, the general molecular arrangement of these minerals is chaotic.
The magnetic field affects each other and does not show the magnetism, but in the external forces (such as magnetic field) guide the molecular arrangement of the direction tends to be the same, it shows the magnetism, which is commonly known as the magnet. Iron, cobalt, nickel, is the most commonly used magnetic substances, basically the magnet is divided into permanent magnets and soft iron, permanent magnets are coupled with strong magnetism, so that the spin of the magnetic material and the electron angular momentum so that the spin of the magnetic material and the electron angular momentum into a fixed direction of the arrangement of the soft magnet is coupled with the electric current (is also a method of adding magnetism) and so the current is removed from the soft iron will slowly lose its magnetism.
The magnet was not invented by man, there is natural magnetite, the first to discover and use the magnet should be the Chinese. That's why the compass is one of the four great inventions of the Chinese.
A magnet is an object or material that produces a magnetic field, usually made of a metal alloy, and has strong magnetic properties. Traditionally, they have been categorized as "permanent magnets" and "non-permanent magnets.
Permanent magnets can be natural products, also known as natural magnets, or artificially created (the strongest magnets are neodymium-iron-boron magnets). Non-permanent magnets heated to a certain temperature will suddenly lose magnetism, which is due to the composition of the magnet of the many "metamagnet" of the arrangement of the order from the disorder caused by the loss of magnetism into the magnetic field, when the magnetization strength reaches a certain value, it is magnetized, "metamagnet" of the arrangement from the disorder again. The arrangement of the "metamagnets" is again from disorder to order.
Basic knowledge: The ancient Greeks and the Chinese found a natural magnetized stone in nature, called "iron absorption stone". This stone could magically pick up small pieces of iron and always point in the same direction after swinging at random.
Early mariners used this magnet as their earliest compass to find their way at sea. Magnets have evolved over thousands of years, and today they are a powerful material in our lives.
By synthesizing alloys of different materials it is possible to achieve the same effect as a magnet, but also to increase the magnetic force. Man-made magnets appeared in the 18th century, but the process of creating stronger magnetic materials was slow until the 1920s when aluminum nickel cobalt (Alnico) was created.
Subsequently, in the 1950s, ferrite was produced, and in the 1970s, rare earth magnets [Rare Earth magnets include neodymium-iron-boron (NdFeB) and samarium cobalt (SmCo)] were produced. Since then, the technology of magnetism has developed rapidly, and the strong magnetic materials have made the components more miniaturized.
Editing magnetization (orientation) direction Most magnetic materials can be magnetized in the same direction until they are saturated, which is called the "magnetization direction" (orientation). Most magnetic materials can be magnetized to saturation in the same direction, which is called the "direction of magnetization" (orientation).
Magnets without orientation (also called isotropic magnets) are much less magnetic than oriented magnets (also called anisotropic magnets). What is the standard industrial definition of "north and south poles"? [The definition of the "North Pole" of a magnet is that the North Pole of the magnet points to the North Pole of the Earth when the magnet is rotated randomly.
Similarly, the south pole of a magnet points to the south pole of the earth. How can you tell the north pole of a magnet without labeling it? Obviously you can't tell by eye.
You can use a compass close to the magnet, and the needle pointing to the North Pole of the Earth will point to the South Pole of the magnet. How do I handle and store magnets safely? Always be very careful, as magnets can attract themselves together and may pinch your fingers.
Magnets can also damage themselves by bumping against each other (knocking off corners or cracking). Keep magnets away from magnetized objects such as floppy disks, credit cards, computer monitors, watches, cell phones, and medical equipment.
Keep magnets away from pacemakers. Larger magnets should have plastic or cardboard spacers between each piece to ensure that the magnets can be easily separated.
Magnets should be stored in a dry, temperature-controlled environment. How do I separate the magnets? Only materials that can be attached to the magnet can isolate it, and the thicker the material, the better the isolation.
What is the strongest magnet? The highest performance magnets are rare-earth magnets, and NdFeB is the most powerful of the rare-earth magnets. However, samarium cobalt is the most powerful magnet in environments above 200 degrees Celsius.
Edit this section of the types of magnets [Figure] magnets, should be called magnets, English Mag, magnets are now divided into two main categories, one is a soft magnet, one is a hard magnet; soft magnets, including silicon steel sheet and soft magnet core; hard magnets, including aluminum nickel cobalt, samarium cobalt, ferrite, and neodymium-iron-boron, which, the most expensive is samarium cobalt magnets, the most inexpensive is ferrite magnets, the highest performance of neodymium-iron-boron magnets, but the most stable and best temperature coefficient is aluminum nickel cobalt. The most stable and the best temperature coefficient is Alnico magnets, users can choose different hard magnetic products according to different needs.
6. What is around with magnets
1, compass meter.
The use of magnetic needles to determine the orientation of the instrument. Used to determine the magnetic azimuth or magnetic quadrant angle of a straight line on the ground. Compass instrument by the compass box, illumination device, magnetic needle composition, simple construction, easy to use, but lower precision.
2, compass.
In ancient times, called Sinan, the main component is a magnetic needle mounted on the shaft, the magnetic needle in the role of the natural geomagnetic field can be free to rotate and remain in the direction of the tangent to the magnetic meridian, the magnetic needle of the South Pole pointing to the geographic South Pole (magnetic field North Pole), the use of this performance can be identified direction.
3, iron absorption stone.
Iron absorption stone is composed of iron, cobalt, nickel and other atoms, the internal structure of its atoms is relatively special. Magnets are capable of generating a magnetic field and have the property of attracting ferromagnetic substances such as iron, nickel, cobalt and other metals.
4. Generator.
The general principle of its construction is: the use of appropriate magnetic conductivity and conductive materials to form a magnetic circuit and circuit for mutual electromagnetic induction to generate electromagnetic power to achieve the purpose of energy conversion.
5, motor.
The electric motor (Motor) is a device that converts electrical energy into mechanical energy. It is the use of energized coil (that is, stator winding) to generate rotating magnetic field and act on the rotor (such as squirrel cage closed aluminum frame) to form a magneto-electric power rotating torque.