Electron at rest generates Electric field. Electron moving without acceleration produces electric and magnetic field. Electron moving with acceleration produces electromagnetic waves.

Please explain the mechanism or the process how this happens. How magnetic field is generated by moving charges? (A moving charge produces a current, or rather a time varying electric field in space.)

Also link https://www.physicsforums.com/threads/why-does-moving-electron-produce-magnetic-field.184619/ said

A moving electron alone actually does not produce a magnetic field. It requires electrons and protons to produce a magnetic field. As the electrons move relative to protons (ions) there is a relativistic charge per unit volume difference between the positive and the negative charges. This causes any external charges to feel a force we know as the magnetic field.

The magnetic field is a relativistic correction to the electrostatic field.

I could not understand these lines. And I don't know much about quantum physics. So, can you please explain in a simpler way? Please use quantum physics also, if it works here.. I may understand it sooner or later.

Also how electromagnetic waves are produced by accelerating charges? An electron with more energy gives it out in the form of photons i.e., E.M. waves. Is it that electric and magnetic fields produced by electron superpose? That could not have possibly happened because varying electric and magnetic field give rise to each other independently..

What happens there actually? And how magnetic field is relativistic correction to electric field?

Thank you.

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  • 1
    $\begingroup$ A moving electron alone actually does not produce a magnetic field.? who said that? thats completely wrong. $\endgroup$
    – Paul
    Dec 26, 2014 at 4:52
  • $\begingroup$ Related physics.stackexchange.com/q/145721 $\endgroup$
    – Paul
    Dec 26, 2014 at 4:54
  • 2
    $\begingroup$ A static electric field in one inertial system has a magnetic field component in another. Electromagnetic fields are observer dependent. I wouldn't believe everything that people without any knowledge of physics are posting on the internet. $\endgroup$
    – CuriousOne
    Dec 26, 2014 at 4:56
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    $\begingroup$ Again magnetic field is not fictitious ,magnetic field is as real as electric field. again related. physics.stackexchange.com/q/65335 $\endgroup$
    – Paul
    Dec 26, 2014 at 5:21
  • $\begingroup$ "A static electric field in one inertial system has a magnetic field component in another". How? Is this concept comes from special relativity? That says, Magnetic field is relativistic. Again, textbook says electricity produces magnetism. Doesn't magnetism have its own independent existency? Once you answered my question on how electrons gained charge, hence an E. field. "the electron gets its charge by the quantum field allowing to create one positive charge state and one negative charge state at the same time, leaving its total charge zero". Then what about magnetic field? Thank you. $\endgroup$
    – Preeti
    Dec 26, 2014 at 6:02

1 Answer 1


Electrons have an electric field. By the influence of an external electric field, the electron is attracted or repelled. Electrons also possess a magnetic dipole moment. This moment is coupled to the rotation of the electron (the magnetic dipole moments of an electron and a positron are opposed with the same direction of rotation). When electrons moving through a magnetic field the magnetic dipoles and therefore also the axes of rotation of the electrons are aligned. Now arises a gyroscopic effect and the electron goes under emission of a photon out of alignment again. Detailed see here.

The acceleration of electrons can be done not only by electric fields. Under the influence of electromagnetic fields, electrons are also accelerated. With a positive acceleration the energy of photons is transmitted parcial to the electron. In case of negative acceleration more energy is emitted as received. As described above, a magnetic field through which electron moves - not parallel to the magnetic field lines! - influential on the electron too. The electron emit photons and its kinetic energy get lost.


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