Why is there magnetism after the circuit is energized?

The microscopic essence is that after the circuit is energized, there is a directional movement of electrons inside the wire, and the moving charge will generate a magnetic field in the space around it, so the macroscopic behavior is magnetic.

Biot-Savar Law.

Ampere's loop theorem.

Do you mean a straight wire that is energized?

Electromagnets. Because of magnetism, a large number of molecules in the nail are magnetized, and it is impossible for irregular molecules to become a regular magnetic field in the same direction, so no matter if you break the nail and beat it again, the nail still becomes magnetic, and only by heating the nail at high temperature, the regularity between the molecules, and the irregular arrangement of molecules, can the magnetism be removed; The easiest way is to heat the nail so that the molecules of the nail move violently, removing the regularity of the molecules inside. A magnetic device with an iron core inside that uses a circle of current to make it magnetic like a magnet is called an electromagnet.

Most of the works are made in strips or hooves. The core should be made of soft iron or silicon steel that is prone to magnetization and loss of magnetism.

<> in order to make the electromagnet pass.

Degaussing immediately after electricity, soft iron or silicon steel materials with fast degaussing are often used to make electromagnets. Obviously, if there is no electricity, there is no magnetic field, and for an electromagnet with a magnetic field, the magnetic field will not be zeroed immediately after being energized, there is a time process, because the magnetic field of the electromagnet is a sensing device that generates a negative electromotive force.

So it doesn't immediately zero the magnetic field.

Strictly speaking, the electromagnetic field of the electromagnet.

, there is still a very small magnetic field between the n and s poles of the electromagnet. This magnetic field is called the remanence of the remanent material, which is generally composed of tens to hundreds of gauss.

Compose. Electromagnets have many advantages: whether the magnetism of the electromagnet can be controlled by carrying virtual on or disconnecting currents.

The magnitude of the magnetism can be controlled by the strength of the current or the number of turns of the coil. Electromagnets have a wide range of applications in daily life. Electromagnets are the magnetic effect of electric current (electromagnetism.

An application that is closely related to life, such as electromagnetic relays, electromagnetic cranes, and maglev trains.

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This is what physics calls electromagnetic induction. An electric current is generated through a change in the magnetic field, which can generate electricity from magnetism and electricity.

This is related to the movement of the current, and some facilities and equipment will choose materials that are relatively fast to degauss the cherry blossom for ridge burial, so the magnetism will disappear after the power-off key is old.

Because the electromagnet is magnetic when it is energized, but when the power is off, the entire system is affected, so the female disappears.

The magnetic field around the energized wire is generated based on the electric current.

The direction of the current of the energized straight wire is the same as the magnetic inductance line.

The relationship of direction can be judged by the rule of the straight wire on the right hand (note the difference with the judgment of the energized solenoid), hold the straight wire with the right hand, the straight thumb is consistent with the direction of the current, and the direction pointed by the curved four fingers is the direction around the magnetic inductance line.

Introduction

From the point of view of modern physics, the only ultimate components that can form charges in matter are electrons (with unit negative charge) and protons (with unit positive charge, so the negative charge is a charged object with excess electrons, and the positive charge is a charged object with excess protons.

The real source of the field where the moving charge produces the magnetic field is the magnetic field produced by the moving electrons or moving protons. For example, the magnetic field generated by an electric current is the magnetic field generated by electrons moving in a wire.

This is the magnetic effect of electric current. That is, if a straight metal wire passes an electric current, then a circular magnetic field will be created in the space around the wire. The greater the current flowing through the wire, the stronger the magnetic field generated. The magnetic field is circular and surrounds the wire.

The principle can be explained as the Ampere molecular current hypothesis: Ampere believes that inside the particles of substances such as atoms and molecules, there is a kind of annular current - molecular current, which makes each particle a tiny magnet, and the two sides of the molecule are equivalent to two magnetic poles, but in fact, the electrons in the molecule do not revolve around the nucleus but the electron cloud formed by the probability of electrons appearing in space.

A single-layer winding is a winding in which only one effective side of the coil is embedded in each stator slot, so its total number of coils is only half of the total number of slots of the motor. The advantage of single-layer winding is that the number of winding coils is small, and the process is relatively simple; There is no interlayer insulation, so the utilization rate of the groove is improved; The single-layer structure does not suffer from phase-to-phase breakdown failures.

A magnetic field is generated around an energized conductor because a magnetic field is generated when an electric current is flowing, and the electrons in an energized conductor form an electric current when driven by a potential difference, so a magnetic field is generated.

According to the ampere loop theorem, the strength of the magnetic field generated by the current passing through a conductor is proportional to the area of the coil around it and the strength of the current. When an electric current flows through a conductor, a magnetic field consisting of magnetic field lines is formed, and this magnetic field forms a toroidal magnetic field line along the conductor's surroundings. The strength of the magnetic field around an energized conductor depends on the shape of the conductor, the strength of the current, and the permeability of the air or other medium around the conductor.

This phenomenon can be described by the right-hand rule, where the four fingers of the right hand are extended in the direction of the current, and the direction of the thumb is the direction of the generated magnetic field. Therefore, the phenomenon of generating a magnetic field around an energized conductor is caused by the magnetic field generated by the electric current.

When a conductor is energized, a magnetic field is generated around it, which is due to the magnetic effect produced by the electric current.

Electric currents are formed by the movement of electric charges in conductors and these moving charges carry the amount and velocity of charge and hence produce a magnetic field. More specifically, according to Ampère's law, an electric current creates a magnetic field around a conductor that is perpendicular to the direction of the current and the shape of the conductor.

This is because the electrons in the electric current are subjected to the Lorentz force when they are in motion, and the direction of this force is perpendicular to the direction of the electron's motion and the direction of the magnetic field. In a conductor, the electrons in the current move in the same direction and hence a magnetic field is formed around the conductor.

This magnetic field is caused by an electric current, not by the conductor itself, so no matter what material the conductor is, whenever an electric current passes through it, a magnetic field will be created in the surroundings. This phenomenon has important applications in electromagnetic induction, motors, transformers and other electromagnetic equipment.

The relationship between the direction of the current of the energized straight wire and the direction of the magnetic inductance line can be judged by the rule of the right hand straight wire (note the difference with the judgment of the energized solenoid), hold the straight wire with the right hand, the straight thumb is consistent with the direction of the current, and the direction pointed by the curved four fingers is the direction around the magnetic inductance line.

The medium is in a non-uniform magnetized state, that is to say, usually the magnetic field lines inside the medium are in a curvilinear state and unevenly distributed; In addition, although there are electric insulators in nature, there are no magnetic insulators (except for superconductors), so there is magnetic flux leakage in ordinary magnetic circuits.

The direction of the magnetic inductance line of the toroidal current also changes with the direction of the current. When studying the magnetic field of a toroidal current, we are mainly concerned with the direction of the magnetic field at each point on the axis of the torus, which can be determined by the right-hand spiral rule: let the four fingers of the right hand bend the same direction as the toroidal current, and the direction of the straight thumb is the direction of the magnetic inductance line on the axis of the torus.

Causes of magnetic fields:

When the conductor is energized, not only will there be a potential difference between the two ends of the line, but there will also be a potential difference between any anterior and posterior spaced positions within the two ends of the conductor.

The potential difference in the conductor should be the trend force difference caused by the imbalance of the charge in the front and rear positions of the conductor, and the trend force will induce a part of the electrons in the current to form a magnetic field line loop in the outer space of the conductor to solve the charge force imbalance caused by the potential difference. A loop field consisting of magnetic field lines is formed around the conductor, and the positive pole of the loop magnetic field is in line with the direction of the current.