How Can a Cylindrical Cavity Create Constant Magnetic Flux Density?

  • Thread starter Thread starter fufufuha
  • Start date Start date
  • Tags Tags
    Physical
AI Thread Summary
A cylindrical cavity can create a constant magnetic flux density when positioned off-center in a long cylindrical conductor with uniform current density. The problem involves calculating the magnetic field (B) in the cavity, which is influenced by the displacement from the conductor's axis. Ampere's Law is suggested as a potential method for solving this, although clarity on the geometry of the setup is needed. Participants in the discussion express confusion about the problem's specifics and suggest posting it in a dedicated homework forum for more focused assistance. Overall, understanding the configuration and applying the right principles are crucial for solving the problem.
fufufuha
Messages
6
Reaction score
0
It is a physical problem.. please help~

In certain experiments it is desirable to have a region of constant magnetic
flux density. This can be created in an off-center cylindrical cavity that is
cut in a very long cylindrical conductor carrying a uniform current density.
The uniform axial current density is J=az j
Find the magnitude and direction of B in the cylindrical cavity whose axis
is dispalced that of the conducting part by a distance d


I am depressed because of this problem. I have know idea... ㅜㅜ

so... I submit this forum. please help~
 
Engineering news on Phys.org
Welcome to the Physics Forums, fufufuha. This sounds like a homework problem, and if it is, it should be posted in the PF Homework forums:


https://www.physicsforums.com/forumdisplay.php?f=158


What textbook is this problem in? It sounds like they want you to calculate the B field inside a hollow cylindrical conductor, where there is a uniform DC current flowing up the cylinder wall. It sounds like the answer should show that the B field is fairly uniform off-axis from the center axis of the cylinder. My guess is that you can use Ampere's Law for this, but my E&M books are all at work at the moment, and I'm home...

Edit -- after re-reading your post, I don't think that I understand the geometry of the conductor and the hollow cylinder portion after all. Is there a diagram associated with this problem?
 
Last edited:
I'm sorry that I'm not good at this forum.

Anyway~ Thanks berkeman
 
Very basic question. Consider a 3-terminal device with terminals say A,B,C. Kirchhoff Current Law (KCL) and Kirchhoff Voltage Law (KVL) establish two relationships between the 3 currents entering the terminals and the 3 terminal's voltage pairs respectively. So we have 2 equations in 6 unknowns. To proceed further we need two more (independent) equations in order to solve the circuit the 3-terminal device is connected to (basically one treats such a device as an unbalanced two-port...
Thread 'Weird near-field phenomenon I get in my EM simulation'
I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
Back
Top