How is a magnetic field generated?
Time:2023-08-30
Views:305
The generation of magnetism is related to the electrons inside atoms. Generally, substances have paired electrons that exhibit magnetic offset. And some substances have unpaired electrons, only half shells of electrons, which can generate a magnetic field due to their spin. These atoms can be called small magnets. Small magnets are arranged in a certain pattern to form crystals, and the directional arrangement of crystals forms a magnetic field. When small magnets have the same direction at the micro level, they exhibit magnetism at the macro level.
When ferromagnetic substances enter a magnetic field, they undergo a reorientation of the paramagnetic field and also possess magnetism. That‘s why iron nails that are attracted by magnets can also absorb other iron nails. This process is called magnetization.
And those non ferromagnetic substances, even when they come into contact with a magnet, do not redirect internally, such as plastic that is not attracted by the magnet. Some stainless steels are also alloy modified and do not exhibit ferromagnetism.
Magnets, magnets, electric currents, and time-dependent electric fields all generate magnetic fields. A permanent magnet is made by magnetizing ferromagnetic substances such as iron or nickel.
The Properties of Magnetic Fields
Magnets exhibit the characteristics of attracting like and repelling opposite.
Magnetic fields, like gravitational fields, do not require a medium and can exist in a vacuum and affect other objects.
The magnetic field can be represented by magnetic lines of force, and the directional state displayed by the iron powder on the edge of the magnet is approximately in the form of magnetic lines of force. The magnetic properties of the North and South Poles are the strongest.
Magnetic substances or currents in a magnetic field are subjected to magnetic forces, such as iron nails that attract the magnet, thus indicating the presence of a magnetic field. A magnetic field is a vector field that has a direction and value at any position in space. The small iron nails absorbed by the magnet will follow a certain direction and represent different levels of attraction at different positions.
Diamagnetism and paramagnetism, ferromagnetism
Gold, silver, and copper have diamagnetism, and all electrons are paired, unable to integrate macroscopic effects and are not magnetized.
Alkali metals and transition elements (excluding iron, cobalt, and nickel) have paramagnetism
Iron, cobalt, nickel, gadolinium, and their alloy compounds have ferromagnetism, and when the external magnetic field is removed, residual magnetism remains, known as hysteresis loops. Only above the Curie temperature can ferromagnetism become paramagnetic, because the disordered tendency of thermodynamics is stronger than the ordered tendency of ferromagnetism.
Electromagnet
Electric and magnetic fields are closely related and can be converted into each other.
The changing electric field generates a magnetic field, and the changing magnetic field generates an electric field.
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The application of electromagnets is very wide, and various electronic instruments often see coils, which are the main body of electromagnets. Transformer, electric motor, generator, magnetic levitation, electromagnetic concentrator, bell, speaker, electromagnetic crane, electromagnetic relay...
Geomagnetic field
The outer core of the Earth‘s core contains molten iron and nickel metals. Scientists believe that the convective motion of this molten liquid will generate an electric current from the east to the west, which in turn generates a magnetic field, known as the "geomagnetic field".
The south pole of the geomagnetic field is located at the geographical north pole, so the north arrow points there and opposites attract each other.
The role of magnetic fields is very significant and can be applied to various aspects. The navigation of the compass utilizes the geomagnetic field, and both electric motors and generators utilize the magnetic field. Electric current will be generated inside the conductor that cuts the magnetic field line.
Strong magnetic fields are harmful to human health.
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