Layman explanation of some simple EM equations

AI Thread Summary
The discussion revolves around the complexities of Maxwell's equations, particularly focusing on the magnetic vector potential and its relation to current density. Participants express confusion about specific terms and their meanings, such as the cross product and the role of conductivity in the equations. There is a mention of Faraday's law and its connection to the equations being discussed, highlighting the interplay between electric and magnetic fields. The context of the equations is clarified as being derived from Comsol Multiphysics, indicating their application in simulations that vary over time. Overall, the conversation seeks a clearer, layman-friendly explanation of these fundamental electromagnetic concepts.
tim9000
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So its been a while since I studied maxwells equations, anyway:
equations.png

So From my ignorant perspective, trying to derive conceptual meaning from these, I can see that the time dependant study there is some conductivity x the partial differential of the magnetic vector potential plus the cross product of mu*B which is H minus SOMETHING? equals the electron current density.

I don't really remember what the magnetic vector potential is (well, that is to say, I remember not really understanding it when I tried learning about it in the first place), or the last term...or what the cross product of H is.
I'm at a similar loss regarding the Frequeny Domain study.

To be honest all I really remember about the cross product is that it is perpendicular to the two vectors being multiplied.If anyone can offer a more indepth explanation of these formulas in English, I mean some maths is fine, but for a layman, that'd be great.

Cheers!
 
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These might help

 
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MexChemE said:
These might help


Thanks for the reply, the second vid was a good refresher about curl (and to a lesser extent divergence), The first one didn't tell me anything I didn't already remember, but it made me try and wonder how Faraday's law might fit into those equations? (given that it has a current and cross product of B in it too).
But I'm still none the wiser about what the 'v' is in that equation (velocity?) or what the curl of H, cross product of Bxv and partial derivetive of A have to do with current density??

Cheers!
 
So am I to assume that these equations aren't a modification/application of one specific Maxwell equation??
 
What is the context of those equations? Where did you see them?

They seem to have something to do with electric and magnetic fields and electric currents in conductors. σ is the usual symbol for electrical conductivity, which is the reciprocal of resistivity: σ = 1/ρ.
 
jtbell said:
What is the context of those equations? Where did you see them?

They seem to have something to do with electric and magnetic fields and electric currents in conductors. σ is the usual symbol for electrical conductivity, which is the reciprocal of resistivity: σ = 1/ρ.
Yeah, they're from Comsol Multiphysics, depending on if you're simulating something that varies over time etc.
 
So I know that electrons are fundamental, there's no 'material' that makes them up, it's like talking about a colour itself rather than a car or a flower. Now protons and neutrons and quarks and whatever other stuff is there fundamentally, I want someone to kind of teach me these, I have a lot of questions that books might not give the answer in the way I understand. Thanks
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