Layman explanation of some simple EM equations

Click For Summary

Discussion Overview

The discussion revolves around the understanding and interpretation of Maxwell's equations, particularly in the context of electromagnetic theory. Participants explore the conceptual meaning of these equations, their components, and their applications, especially in relation to electric and magnetic fields and currents in conductors.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about the magnetic vector potential and its relation to current density, questioning the meaning of various terms in the equations.
  • Another participant shares resources that may help clarify concepts like curl and divergence, indicating a desire for deeper understanding of how these relate to Maxwell's equations.
  • A participant wonders how Faraday's law fits into the equations discussed, particularly regarding the role of current and the cross product of magnetic fields.
  • There is a question about whether the equations in question are modifications or applications of a specific Maxwell equation.
  • Participants discuss the context of the equations, noting their relevance to electric and magnetic fields and electric currents in conductors, with references to electrical conductivity and its relation to resistivity.
  • One participant mentions that the equations are derived from Comsol Multiphysics, suggesting a practical application in simulations.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and confusion regarding the equations and their components. There is no consensus on the interpretation of specific terms or how they relate to one another, indicating multiple competing views and unresolved questions.

Contextual Notes

Participants highlight limitations in their understanding of specific terms and concepts, such as the magnetic vector potential, the meaning of 'v' in the equations, and the relationship between different components of the equations. There is also mention of the context in which these equations are used, specifically in simulations that vary over time.

tim9000
Messages
866
Reaction score
17
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 dependent 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!
 
Physics news on Phys.org
These might help

 
  • Like
Likes   Reactions: sophiecentaur
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.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 32 ·
2
Replies
32
Views
4K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 11 ·
Replies
11
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 27 ·
Replies
27
Views
4K
  • · Replies 5 ·
Replies
5
Views
4K
Replies
2
Views
2K