Overview of Electromagnetic Fields

Electromagnetic field (electromagnetic field) is the unity and general term of the electric and magnetic fields that are intrinsically linked and interdependent. The time-varying electric field produces a magnetic field, and the time-varying magnetic field produces an electric field. Electromagnetic fields can be caused by charged particles moving at a variable speed, or by currents with varying strengths. Regardless of the cause, the electromagnetic field always propagates around at the speed of light, forming electromagnetic waves. Electromagnetic field is the medium of electromagnetic action, it has energy and momentum, and it is a form of matter existence. The properties, characteristics and the law of motion change of the electromagnetic field are determined by Maxwell's equations.

The electromagnetic field is the medium of electromagnetic action, and it is a unified whole. The electric field and the magnetic field are its two sides that are closely related and interdependent. The changing electric field produces a magnetic field, the changing magnetic field produces an electric field, and the changing electromagnetic field propagates in space in the form of waves. . Electromagnetic waves propagate at a limited speed, have exchangeable energy and momentum, the interaction between electromagnetic waves and objects, the mutual transformation between electromagnetic waves and particles, etc., all prove that the electromagnetic field is an objectively existing substance, and its "special" is only that it has no static mass. .

In electromagnetism, magnets, magnets, currents, and time-dependent electric fields all generate magnetic fields. The magnetic material or current in the magnetic field will feel the magnetic force due to the action of the magnetic field, thus showing the existence of the magnetic field. A magnetic field is a vector field; it has a direction and magnitude at any location in space.

Main application areas

Electromagnetic field (or wave) is a form of energy and is the most important energy source in the world today. The research field involves the generation, storage, transformation, transmission and application of electromagnetic energy.

As the carrier of information, electromagnetic waves have become the main means of information release and communication. The research contents include information release, exchange, transmission, storage, processing, reproduction and application.

Electromagnetic waves are an important means to detect the unknown world. The main research fields are the interaction characteristics of electromagnetic waves and targets, target detection and the acquisition of their characteristics.

As a means of measurement and control and positioning technology, electromagnetic waves constitute the application basis of modern industry, transportation, national defense and other fields.