Potentially silly question re magnetism....

[essenmein]

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?

 

[essenmein]

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.

 

[BvU]

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.

 

[osilmag]

Essenmein, you might have Lorentz' Law in mind.
$F=qvB$.

 

[osilmag]

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.

 

[essenmein]

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?

 

[Dr_Nate]

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.

 

[essenmein]

A neutron has a magnetic dipole moment.

Did not know that! Off to wiki I go...

 

[tech99]

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.

 

[essenmein]

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.

 

[BvU]

There is a big difference between an accelerating charge and a moving charge