What is the connection between electricity and magnetism, and what is electricity and magnetism

There can be several levels of answer to this question:

The answer given by the middle school teacher is: moving electrons produce a magnetic field.

The definition in undergraduate physics textbooks is:

A changing electric field produces a magnetic field, and a periodically changing electric field produces a periodically varying magnetic field.

For a more specific distinction, see Maxwell's equations (of course, a certain mathematical foundation is required), the vector analysis of the problem in the book Electromagnetic Fields and Electromagnetic Waves, electrostatic fields, electric and magnetic fields of constant current, solutions of electrostatic fields, time-varying electromagnetic fields, plane electromagnetic waves, radiation of electromagnetic waves, and conductive electromagnetic waves.

Electromagnetism – There is a magnetic field around an energized conductor.

Magnetoelectric - Metal conductors cut magnetic inductance lines to produce electromotive force (electric current occurs when connected to the path), and the change in the electric field causes a change in magnetic flux rather than a magnetic field.

Where there is an electric current, there is a magnetic field.

The change in magnetic flux in turn generates an electromotive force.

Ah, there's something else to say

In short, the above two sentences.

Electricity and magnetism are twin brothers, and moving charges can be magnetic, that is, exhibit magnetism; The changing magnetic field can generate electricity, among which there are two kinds of induced electromotive force and dynamic electromotive force.

First, the nature is different.

1. Magnetoelectric properties: using the principle of electromagnetic induction, the input movement speed is converted into the induced potential output in the coil.

2. Electromagnetic properties: a sensor that converts the measured physical quantity into induced electromotive force.

Second, the principle is different.

1. Magnetoelectric principle: according to the law of electromagnetic induction, when the W turn coil moves in a constant magnetic field, let the magnetic flux through the coil be , then the induced potential e in the coil and the magnetic flux change rate d dt have the following relationship: e=-w(d dt).

2. Electromagnetic principle: when the magnetic gap changes caused by the rotation of the speed measurement gear, the probe coil generates an induced electromotive force, and its amplitude is related to the speed. The higher the speed, the higher the output voltage, and the output frequency is proportional to the speed.

The speed is further increased, the magnetic circuit loss increases, and the output electromotive force tends to be saturated. When the rotational speed is too high, the magnetic circuit loss increases and the electric potential drops sharply. There is no essential difference between a magnetic water boiler and an electromagnetic water boiler.

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Electromagnetic energy and magnetic energy are two different things. Electromagnetic energy is the generation of electric currents between objects with potential differences, which is essentially the directional movement of electrons. Magnetic energy is the magnetic field produced by a magnet.

Electricity and magnetism are two different things. Electrical energy is the generation of electric current between objects with potential difference, which is essentially the directional movement of electrons. Magnetic energy is the magnetic field produced by a magnet.

Ask yourself questions ??

Please read the junior high school physics textbook and review it again.

1. Electricity is an inherent property of matter in the universe, there are two kinds of matter, positive and negative, positive and negative are combined by a strong force of attraction to form atoms, molecules, etc., the smallest charged particle is electron, the magnetic field can be said to be generated by the spin of electrons, and the changing electric field produces a magnetic field.

2. The phenomenon of electricity generated by the interaction between the electromagnetic field and the conductor is called electromagnetic induction. After H. C. Oster's discovery of the magnetic effect of electric current in 1820 revealed one aspect of the connection between electricity and magnetism, many physicists explored whether magnetism could also produce electricity, and conducted many experiments.

3. The cause of electromagnetic phenomena is that the movement of electric charges fluctuates and forms a magnetic field, so all electromagnetic phenomena are inseparable from electric fields. Electromagnetism is a sub-discipline of physics that studies the interaction between electric and magnetic fields, as well as their laws and applications.

When an electric current passes through the conductor, a magnetic field is generated around the conductor (the space around the magnet is dyed by magnetic force), that is, "electromagnetism". When a conductor cuts a magnetic field line or the magnetic field line passing through the coil changes, an induced electromotive force or induced current is generated in the conductor or coil, which is called "magnetic electricity".

There is a magnetic field around the current, as evidenced by the Danish Oster.

The energized solenoid is judged by the pole, and the ampere of the cong cave extends the right hand.

The four fingers follow the current, and the direction of rotation cannot be reversed.

The thumb is the n pole, and the palm cut is marked as the s.

Electromagnetic induction Faraday, magnetic generation of electricity to close the circuit.

Some conductors cut magnetic wires, and there are induced current lines.

The direction changes to alternating current, and the mechanical energy is converted into electrical energy.

When an electric current passes through a conductor, a magnetic field (the space around the magnet with magnetic force) is generated around the conductor, which is called "electromagnetism". When a conductor cuts a magnetic field line or a magnetic field line passing through a coil changes or changes, an induced electromotive force or induced current will be generated in the conductor or coil, that is, "magnetic electricity".

The memory mantra of electromagnetism has a magnetic field around the electric current, as evidenced by the Danish Oster.

The energized solenoid is judged by the pole, and the ampere rule is extended to the right hand.

The four fingers follow the current, and the direction of rotation cannot be reversed.

The thumb is the n pole, and the palm cut is marked as the s.

The memory formula of magnetism and electricity is electromagnetic induction Faraday, and the magnetism and electricity must be closed.

Part of the conductor cut socks collapsed magnetic wires, induced current lines in them.

The direction changes to alternating current, and mechanical energy is converted into electrical energy.