Current Concentrated Along Axis

  • Thread starter Thread starter ResonantW
  • Start date Start date
  • Tags Tags
    Axis Current
AI Thread Summary
Current in a fat wire is theorized to concentrate along the wire's axis due to the attraction between parallel wires. However, there are concerns about why this concentration might not occur, with suggestions of electric repulsion among conduction particles. The discussion touches on the implications of this behavior for electric fields, specifically that a curl in the current density would contradict the fact that the curl of an electric field is zero. Participants express confusion about the underlying physics and seek clarification on Griffiths' theories. Understanding these dynamics is crucial for deeper insights into electrical conduction in wires.
ResonantW
Messages
9
Reaction score
0
Griffiths brings up a point that it might make sense that current in a fat wire would want to concentrate itself mainly along the axis of the wire, given that parallel wires attract each other.

He then asks us to figure out why this might not happen, but to be honest I would think it should! The only thing I can think of is some sort of electric repulsion in the conduction particles' rest frame, but I feel like there are more subtle points in transforming the frames like this. Where am I going wrong?
 
Physics news on Phys.org
hi there :)

who is Griffiths and do you have a link to his study ?

Dave
 
That would give j a curl. Since j=\sigma E, that would give E a curl, but curl E=0.
 

Thread 'Maxwell stress tensor'

This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
View full post »
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'

Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'

Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
View full post »

Similar threads

I Resulting magnetic field due to the passage of an AC current
Replies
27
Views
2K
B The historical war of currents in Mains Power Distribution: AC vs DC
Replies
7
Views
2K
Current: the speed of charges vs the number of charges past a point
Replies
37
Views
3K
I Capacitor surface charge movement current, relativistic effects
Replies
2
Views
1K
I Two ways of constructing electromagnetism, which is correct?
Replies
7
Views
1K
B Designing a current sensor for 50mA up to several dozen Amps
Replies
17
Views
2K
Arbitrariness of the surface involved in the displacement current
Replies
2
Views
1K
Electric field due to current carrying conductor
Replies
2
Views
3K
I Questions about cancelation of induced EMF and minimizing eddy currents
Replies
4
Views
2K
Applied physics of current probe / generator clamps
Replies
3
Views
1K

Hot Threads

Recent Insights

Back
Top