conceptual understanding of electromagnetism

[PG1995]

Hi

I understand that this is a very complex topic but we will try to keep it simple and uncomplicated! Thanks.

It is said that electrons in themselves are the reason for magnetism. As is explained in the linked page that if an electron is moving CW if viewed from the top, then electron's top is North and bottom is South.

Linked page: **broken link removed**

I have a couple of questions to ask but asking them in steps would be a wise choice. In the first place I don't understand how we get circular magnetic field lines around a conducting wire. I understand that when DC current is flowing through a conductor electrons are continuous moving in one direction. But how do their collective movement create circular field lines?

This is how electron's magnetic field looks:
**broken link removed**

Could you please refer me to some diagram etc. which shows how electrons' magnetic field sums up to give circular lines, or explain it yourself?

Magnetic field lines around a wire:
**broken link removed**

Thank you for your help.

Regards
PG

 

[Sceadwian]

Magnetic fields are created by any moving charge carrier, or a time varying electric field, the electron is only one type of charged particle, albeit one of the more important one's. Honestly for me at least an intuitive understanding of the exact interrelation between the magnetic and electric fields has always been a bit beyond my grasp, but that's because I don't study the math closely enough.

You may want to look more closely into the Photon, which is the elementary particle that gives rise to the electric and magnetic fields, understanding it may help.

 

[MrAl]

Hi

I understand that this is a very complex topic but we will try to keep it simple and uncomplicated! Thanks.

It is said that electrons in themselves are the reason for magnetism. As is explained in the linked page that if an electron is moving CW if viewed from the top, then electron's top is North and bottom is South.

Linked page: **broken link removed**

I have a couple of questions to ask but asking them in steps would be a wise choice. In the first place I don't understand how we get circular magnetic field lines around a conducting wire. I understand that when DC current is flowing through a conductor electrons are continuous moving in one direction. But how do their collective movement create circular field lines?

This is how electron's magnetic field looks:
**broken link removed**

Could you please refer me to some diagram etc. which shows how electrons' magnetic field sums up to give circular lines, or explain it yourself?

Magnetic field lines around a wire:
**broken link removed**

Thank you for your help.

Regards
PG

Hi again PG,

Comparing those two fields although at first it doesnt seem like it, is like comparing the proverbial apples to oranges. That's because the two field are generated because of different movements for the most part. One is mostly due to the spin and the other the displacement. Just like a bullet speeding through the air, it spins but that doesnt cause it to shoot forward. Just like an airplane that can tilt and spin or move forward faster or slower, the spin really isnt what makes it go forward because that's considered another dimension of the movement so it has it's own attributes apart from the forward movement.

The field from the electron spin shown in your top pic does not contribute as much to the field shown in your bottom pic which is mostly due to the transverse movement of the electron, not the spin, or at least not as much from the spin. This means that the theory of the field shown in your bottom pic can not be derived from the spin alone, but mainly comes from the movement of the electron in the wire (at least from the perspective of the theory where the electron causes the field).
When the electron moves through the wire it would have a circular field just like that shown in your bottom picture, even if the wire was not there.

To get more info on this it might be helpful to look up the difference between the spin field and the orbital field. To get more theory on the electron field through the wire you can look up what happens when an electron moves through empty space.

What i think is interesting is if we slice the electron to create a disk, then cut that in half to form a "D" shaped slice, then rotate that along the vertical axis (the straight vertical line of the "D"), we get a field like that from the electron spin. Alternately, tracking a point on the surface of the electron anywhere except near the axis of spin we see that point generating a field similar to the electron itself traveling through the wire.