Displacement Current: Difference & Example

AI Thread Summary
Displacement current is not always equal to conduction current; it is a component of Maxwell's equations, specifically the Ampere-Maxwell Law. This law describes the relationship between electric fields, magnetic fields, and current densities. The discussion highlights the need for context when comparing displacement and conduction currents, as they serve different roles in electromagnetic theory. Participants are encouraged to provide specific examples to clarify their understanding of the relationship between these two types of currents. Understanding the distinction is crucial for grasping the fundamentals of electromagnetism.
arvindsharma
Messages
21
Reaction score
0
Is displacement current always equals to conduction current?if not then can anyone give me an example for it?if yes,then can anyone prove it?
 
Physics news on Phys.org
The socalled "displacement current" is a misnomer. It's not a current but it's simply part of one of Maxwell's equations, the Ampere-Maxwell Law, which reads in Heaviside-Lorentz units
$$\vec{\nabla} \times \vec{B}-\frac{1}{c} \partial_t \vec{E}=\frac{1}{c} \vec{j}.$$
This is the "microscopic form" of the law, and ##\vec{j}## is the total current density.

The source of the electromagnetic field are charge and current densities.
 
I think you should tell us some details about the context or background or origin of your question. Do you have a specific example in mind, where the two currents are equal?
 
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...
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...
Back
Top