Current around rotating objects?

  • Thread starter Thread starter mubashirmansoor
  • Start date Start date
  • Tags Tags
    Current Rotating
AI Thread Summary
An electromagnetic field is not typically produced around a rotating object unless it has free electrons that can oscillate. The rotational speed of physical objects is limited and much slower than the speed of electrons, which complicates the generation of an EM field. Without free electrons, the rotation alone is unlikely to create any electromagnetic effects. The discussion also references practical applications like microwave ovens and radar, which utilize electromagnetic principles. Overall, the relationship between rotation and electromagnetic fields remains uncertain and requires further exploration.
mubashirmansoor
Messages
258
Reaction score
0
I'd be thankfull to know if an electromegnetic field is produced around a rotating object(extreamly fast rotations like electrons.)

It's urgent thankyou,
 
Physics news on Phys.org
I believe that electromagnetic field is produced around oscillating object. Rotating? I guess not.
 
mubashirmansoor said:
I'd be thankfull to know if an electromegnetic field is produced around a rotating object(extreamly fast rotations like electrons.)

It's urgent thankyou,

Hmmm... I'm no expert on the subject, but my thoughts are this:

a) You can only rotate a physical object so fast before it will break apart, and that rotational speed, regardless of materials/methods used, is far less than the speed of electrons whirling around an atom.

b) If the object has no "free-electrons" I doubt that rotation of the object would create any EM field.

c) If the object does have free electrons, I'm not sure that objects rotation would cause any oscillation of the free electrons necessary to generate an EM field.

Again, I do not know for certain.
 
mubashirmansoor said:
I'd be thankfull to know if an electromegnetic field is produced around a rotating object(extreamly fast rotations like electrons.)

It's urgent thankyou,
That's how microwave ovens and radar work, mate.

http://en.wikipedia.org/wiki/Magnetron

(EDIT -- I seem to remember that the mixer oscillator for HP spectrum analyzer oscillators designed in Santa Rosa, CA in the 1980s used the precession of a small metallic sphere somehow, but I'm not able to get any google hits on that at the moment...)
 
Last edited:
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