Electron's magnetic behavior

[gespex]

Hello all,

I have a few questions regarding the magnetic charge of an electron. First of all, I read an electron behaves like a bar magnet, which would suggest the south-pole of one electron would attract the north-pole of another electron. However, electrons also repulse each other. So what does this mean? Is the repulsing force just a lot stronger than the attracting force?

Also, imagine two electrons, their north poles closest to each other, at a certain distance. What is the repulsing force between the two?


Thanks in advance,
gespex

 

[tommyli]

Hi gespex,

Yes, what you are saying is true, although in physics we usually do not talk about magnetic poles, instead we talk about magnetic moments and the interaction between magnetic moments. A monopole (magnetic pole) is a single point containing magnetic "charge" from which magnetic flux lines emanate; in the currently accepted model for electromagnetism which is based on Maxwell's equations, these do not exist. A magnetic moment, rather than being a single point, defines a direction in space, and carries no magnetic "charge." Furthermore the electron is a quantum object, and its magnetic moment is proportional to its spin (its intrinsic angular momentum).

Two electrons will interact via electrostatic force, which causes them to repel. They will also interact via the magnetic interaction, which is usually called the hyperfine interaction, which causes their spins to align.

Hope this answers your question!

 

[Naty1]

[I read an electron behaves like a bar magnet, which would suggest the south-pole of one electron would attract the north-pole of another electron./QUOTE]


What primarily characterizes an electron is it's electric charge...and of course, mass. It DOES have a magnetic orientation, and that becomes noticeable, for example, when electrons become crammed together as in energy levels around a nucleus. But it is a SMALL effect compared with the strength of electron charge.


http://en.wikipedia.org/wiki/Electron_spin says this:

The electron is a charged particle. Its angular momentum comes from two types of rotation: spin and orbital motion. From classical electrodynamics, a rotating electrically charged body creates a magnetic dipole with magnetic poles of equal magnitude but opposite polarity. This analogy holds as an electron indeed behaves like a tiny bar magnet. One consequence is that an external magnetic field exerts a torque on the electron magnetic moment depending on its orientation with respect to the field.

Note the word TINY...that means "weak"...