Have you ever heard Electric Field of one turn Solenoid?

AI Thread Summary
The discussion revolves around the concept of the electric field in a one-turn solenoid, referencing an MIT example. The original poster expresses confusion regarding the dimensionality of the solenoid, questioning whether it is two-dimensional or three-dimensional, and the implications for its classification as a solenoid. They also challenge the validity of Equation (14), which states that the electric field inside the solenoid is uniform and axial, equating it to the surface current. The poster suggests that the surface current density notation may be misleading and proposes that the equation should incorporate a unit vector in the z-direction. Overall, the thread seeks clarification from experts in electrodynamics on these concepts.
walkinginwater
Messages
21
Reaction score
0
Have you ever heard "Electric Field of one turn Solenoid?

hi, guys:
Have you ever heard "Electric Field of one turn Solenoid"? Here is a example from MIT.
  1. Click on the weblink: http://web.mit.edu/6.013_book/www/book.html
  2. Click on the Chapter 10 in the left part of the screen!
  3. Now Click on 10.1 , which say something about Magnetoquasistatic Electric Fields in Systems of PerfectConductors
  4. In the Example 10.1.2, you will find the Electric Field of one turn Solenoid

I am confused about this example!
First I cannot understand "a circular cylindrical conductor having an inside radius a much less than its length in the z direction" Is this solenoid 3 dimension or 2 dimension? If it is 3 dimension, is it still " solenoid'?
Second I cannot agree with the Equation (14), which claims that "the field inside the solenoid is uniform, axial, and equal to the surface current " ??

Anyway, I cannot understand the example at all, does anybody who is a guru in Electrodynamics can understand that?
 
Last edited by a moderator:
Physics news on Phys.org
I believe Figure 10.1.3 shows the cross section view of a "cyliner". The cylinder height, z direction, is into the page.

Equation 14: the words do say "surface current" but K is surface current denisty, Amps/length. I think the Iz in this equation should be possibly Nz (unit norm in Z direction) since H is a bolded vector.

But by the same reasons discussed in 10.1.1 the H field would be essentially uniform and axial in the z direction given a very long and very small dia.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
Back
Top