Several questions in electromagnetics

  • Thread starter Thread starter CheyenneXia
  • Start date Start date
  • Tags Tags
    Electromagnetics
Click For Summary

Discussion Overview

The discussion revolves around several questions related to electromagnetics, specifically addressing concepts such as Kirchhoff's Voltage Law (KVL) in AC circuits, the distinction between conduction and convection current densities, and the boundary conditions for time-varying fields. Participants explore theoretical implications and practical interpretations within the context of electromagnetic theory.

Discussion Character

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

Main Points Raised

  • One participant questions how KVL can hold in AC circuits when the line integral of the electric field is non-zero due to changing magnetic fields, suggesting a potential contradiction.
  • Another participant explains that the apparent violation of KVL is addressed by considering parasitic inductance in the circuit, which accounts for the magnetic fields generated by the wires.
  • A different participant provides a mathematical reasoning for the boundary conditions of electric and magnetic fields, arguing that certain terms approach zero under specific conditions.
  • There is a discussion about the differences between conduction current density (J=σE) and convection current density (J=ρv), with one participant seeking clarification and examples of each type.
  • One participant reflects on the complexities of electromagnetics, likening the learning process to peeling layers of an onion, indicating ongoing confusion and the need for further exploration.
  • Another participant expresses skepticism about the applicability of certain electronic theorems in physical contexts, particularly regarding KVL and the nature of electric fields in varying magnetic fields.

Areas of Agreement / Disagreement

Participants express differing views on the validity of KVL in the presence of time-varying fields, with some suggesting that traditional circuit analysis methods may not fully capture physical realities. There is no consensus on the interpretation of boundary conditions or the distinctions between current types, indicating ongoing debate and exploration.

Contextual Notes

Participants note that the definitions and applications of conduction and convection currents may depend on specific contexts, and the discussion reflects a variety of interpretations and understandings of electromagnetic principles. The complexity of the subject matter is acknowledged, with references to unresolved questions and the need for deeper study.

Who May Find This Useful

This discussion may be of interest to students and professionals in electrical engineering, physics, and related fields who are grappling with foundational concepts in electromagnetics and seeking clarification on complex theories and their applications.

  • #31
marcusl said:
Also I'll point out that you have completely hijacked this thread so it is focused on a topic taken from your own, different thread.

You read the original question? Question 1 is on KVL under magnetic field condition. Question 3 about tangential boundary condition which talk about free charge and free current. Where is it off the topics when I talk about MIT professor Levine. He made a video demonstrated KVL don't hold under varying magnetic field. AND current in transmission line are consequence of EXACTLY the tangential boundary condition between good conductor and dielectric. You watch the video I posted before you speak?
 
Engineering news on Phys.org
  • #32
Locked pending moderation.
 
  • #33
This thread will remain closed. I've asked yungman to take the debate to PMs if he wants to continue it.
 

Similar threads

  • · Replies 30 ·
2
Replies
30
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
10
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 17 ·
Replies
17
Views
4K
Replies
8
Views
4K