# How electrons act under rotating magnetic field?

I study Power Engineering in University. Today I asked my lecturer to explain me exactly how atom's electrons act under spinning rotor's magnetic field, that generated dynamic electricity. But he even didn't gave me to finish my question and said : "Explaining it to you is useless, you are not capable of understanding it". I felt very angry hearing these words, like I was an idiot. So I have some thoughts about electrons behavior under spinning rotor's magnetic field and I want your answer, is this theory correct and if it's not than why?

here is my theory:

Consider this is simple atom:

When magnetic field cross atoms, if magnet's north side (+) is near to this atom the center of electron's path (gray circle) will not be on the center of nuclear, it will move toward magnet, because magnet has north side (+) and electron has (-) potential. As I believe the Voltage (U) is distance between center of nuclear and the center of electron's path. And the number of these atoms make amps.

That's why increasing rotor's magnetic field makes more voltage, and that's why air's ionization happens around high voltage wires (voltage like: 220 kv, 500 kv). Nuclear has not enough power hold electron and so this electron moves to new air's nuclear. I think that also explains why Current and Voltage are 90 degrees out of phase.

Please read my theory and tell me I am right or not, I really want to understand how this everything is done.

Also my lecturer told me that every information I can find on internet is written by fools and foolers are reading them. So I want to tell him that he is WRONG!!!

• The behaviour of an electron is determined by the laws of quantum mechanics not classical mechanics. An electron may not have definite position or momenum. Also. eletrons don't rotate around the nucleus in classical orbits. Mar 30, 2013 at 20:26
• This is a great question, and it is excellent that you are excited about the subject and you are trying to better understand it. That being said, you're very far off on your conception of numerous concepts in electrodynamics. Stationary electric charges do not feel forces from stationary magnetic fields---electric charges (denoted '+' and '-') are different from magnetic poles (denoted 'N' and 'S'). You need to read a basic textbook like, Griffiths Introduction to Electrodynamics Mar 30, 2013 at 20:58

Well, your lecturer certainly shouldn't have put it like this, however it's true that you have got a lot wrong here. It's stuff you definitely will need to understand better if you're studying power engineering.

First, you seem to think that electrons are attracted by magnetic north poles. They aren't; in fact stationary charges and magnetic fields aren't concerned with each other in any way at all1!

Next, you're talking about electrons in circular orbits about the nucleus. That's roughly the Bohr model, which kind-of-sort-of-works, but not really. You want to familiarise yourself to the orbital model, which describes very well how bound electrons actually behave.
Even in an orbital, you might be inclined to talk about "the nucleus is off the center by a distance proportional to the voltage". That's again kind-of-sort-of-right since the nucleus lies in a locally-harmonic potential which can be read as "pertubation by an electric field (which in a fixed capacitor is proportional to the voltage) will cause a proportional displacement of the nucleus", but the way you phrase it it's still nonsense. Voltage "is" not a distance, it's a potential (i.e. energy).

Anyway, this isn't actually relevant to understanding rotating-magnet phenomena, i.e. inductance in coils. These are concerned only with conduction electrons, which aren't bound to any particular atom at all but "move" through the entire conductor, which is why there can be currents. It is these moving electrons that experience a significant force in the presence of a magnetic field. What current actually is is the number and "speed" with which these electrons move through the conductor, while even a strong displacement of the bound (valence) electrons would not consolidate a current2.

Now, all of this seems to say there isn't any such thing as inductance. Sure there is! Only, it's rather more complicated: electrons at rest aren't affected by stationary magnetic fields, but in the same way that moving electrons are affected by such fields, moving magnetic fields (or, more generally, time-varying magnetic fields) also cause a Lorentz force upon resting electrons. So, effectively, what you're saying about electrons being moved around by moving magnetic fields isn't all that wrong again, it only works quite a bit differently. A moving magnetic field will in fact "push resting conductance electrons" through a wire a bit, i.e. induce a voltage. But that voltage really can't be read as anything displacement-like, it's a fundamental electrodynamic phenomenon. In fact, the voltage in its pure, exact value can only be measured if you prevent the conductance electrons from moving, as otherwise they would themselves cause a magnetic field cancelling the inductance etc. pp..

As you see, the whole subject is quite a bit more complicated than you thought. I'm sure you are capable of understanding it, but probably not in a few minutes, which is why your lecturer can't really be blamed for not trying to explain it right away.

1Actually, electrons are also small magnets themselves (they have an instrisic quantum-mechanical spin) and therefore are attracted to inhomogenic magnetic fields, but that's quite another issue.

2Actually, it would... but that's mostly relevant in the high-frequency-regime, i.e. bound electrons that jiggle back and forth very quickly.

• Thank you a lot, I know my theory was wrong, and I think I will now start learning with the correct theory. Thank you a lot again. I will left this question ununswerd awhile if someone tries to write more Mar 30, 2013 at 21:15