Potentially silly question re magnetism....

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Discussion Overview

The discussion revolves around the nature of magnetic fields and the interactions of charged particles within those fields. Participants explore concepts related to magnetic flux density, the effects of moving charges, and the implications of Lorentz's Law. The conversation includes theoretical considerations and clarifications regarding the behavior of charged and uncharged particles in magnetic and electric fields.

Discussion Character

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

Main Points Raised

  • One participant notes that the unit for flux density is Tesla and questions how the magnetic field created by a moving charge interacts with an external magnetic field.
  • Another participant suggests that the presence of a moving charge alters the uniformity of the magnetic field it travels through.
  • It is proposed that a particle does not interact with its own field, drawing a parallel to electrostatics where a test charge only feels fields from other charges.
  • Discussion includes the idea that the magnetic field created by a moving charge is circular, and only part of this field interacts with an external magnetic field.
  • A participant raises a question about whether forces experienced by charged particles are due to field interactions rather than the fields interacting with the particles themselves.
  • Another participant corrects the previous claim about uncharged particles, stating that neutrons have a magnetic dipole moment, which allows for interaction with magnetic fields.
  • One participant reflects on the force experienced when accelerating a charge, suggesting it arises from pushing against its own distorted field, equating the work done to the radiated energy.
  • A distinction is made between accelerating charges and moving charges, indicating a nuanced understanding of their behaviors.

Areas of Agreement / Disagreement

Participants express various viewpoints regarding the interaction of charged particles with magnetic fields, with no consensus reached on the nature of these interactions or the implications of the concepts discussed.

Contextual Notes

Some statements rely on assumptions about the behavior of fields and particles, and the discussion includes unresolved aspects related to the definitions of terms and the implications of Lorentz's Law.

essenmein
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The unit for flux density (a derived SI unit) is Tesla, this can be expressed as T = N*s/C*m.

Ie a particle with charge of 1 coulomb, traveling at 1m/s perpendicular to a magnetic field of 1Tesla experiences a force of 1N.

So my question, and this is more for my understanding since I'm not questioning Maxwell's equations!

Since moving charge is what essentially creates a magnetic field (ignoring displacement current for now, all though this is still something I don't fully understand), is this taken into consideration in the equation?

Or is it precisely the interaction of the two fields, the 1T field the particle is traveling through and the field the moving charge is creating that cause this force to be experienced by both the particle traveling and an opposite force on the thing making the magnetic field?
 
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This question I guess is coming from the thought that the traveling 1 coulomb charge is creating its own field, and therefore due to vector addition of the two fields, the 1 coulomb charge would not be in a uniform 1T field any more purely due to its presence.
 
By posting in your own thread you have taken it off the unanswered threads list.

I think your answer is: a particle does not interact with its own field. Compare the situation of your moving charge in a B field with electrostatics: a test charge sitting at some point only 'feels' the fields from other charges.
 
Essenmein, you might have Lorentz' Law in mind.
##F=qvB##.
 
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However, to go along your thinking, the magnetic field that the moving charge would create would be circular. So, only part of the circular field would be canceled by the perpendicular magnetic field thus leaving the other part of the circular field to make it move. And that other part is would be in the direction of the perpendicular magnetic field, thus you would be back at Lorentz' Law.
 
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Would the following statement be correct:The forces experienced by a charged particle either in motion in a static magnetic field or stationary in the presence of an electric field, is due to the field interactions between the particles, not the fields interacting with the particles themselves.

Ie an uncharged particle, eg neutron, is not able to create a magnetic or electric field, and therefore cannot interact with them, therefore no forces experienced?
 
essenmein said:
Ie an uncharged particle, eg neutron, is not able to create a magnetic or electric field, and therefore cannot interact with them, therefore no forces experienced?
A neutron has a magnetic dipole moment.
 
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Dr_Nate said:
A neutron has a magnetic dipole moment.

Did not know that! Off to wiki I go...
 
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BvU said:
I think your answer is: a particle does not interact with its own field.
May I suggest that when I accelerate a charge, I feel a force opposing me, which arises because I am pushing the charge against its own field, which I have distorted. The work I do against this force is equal to the radiated energy.
 
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  • #10
tech99 said:
May I suggest that when I accelerate a charge, I feel a force opposing me, which arises because I am pushing the charge against its own field, which I have distorted. The work I do against this force is equal to the radiated energy.

Cool this is basically what I thought, but couldn't quite put my finger on an explanation.
 
  • #11
There is a big difference between an accelerating charge and a moving charge
 

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