Kinetic energy of electron in non-uniform B?

[jason12345]

The kinetic energy of a bar magnet changes in a non-uniform magnetic field so is there experimental evidence that this is true for the kinetic energy of an electron since it possesses an intrinsic magnetic moment?

Cheers, for your interest

 

[Drakkith]

Any charged particle will react to a magnetic field because it is charged, not because it has a magnetic moment. In fact, the magnetic moment only exists because it is charged. The fact that you can apply a force on an electric charge is the reason we use magnets for things like plasma containment and fusion reactors.

 

[jason12345]

Any charged particle will react to a magnetic field because it is charged, not because it has a magnetic moment. In fact, the magnetic moment only exists because it is charged. The fact that you can apply a force on an electric charge is the reason we use magnets for things like plasma containment and fusion reactors.

Yes, a static magnetic field will change the momentum of an electron and we're told also that it doesn't do work either so the electron's kinetic energy remains constant. On the other hand, a non-uniform magnetic field causes the centre of mass of a bar magnet to accelerate with the kinetic energy coming from the magnet. Does this mean that an electron will have a linear acceleration also?

 

[Drakkith]

Yep, the electron will accelerate.

 

[jason12345]

Yep, the electron will accelerate.

I didn't express myself correctly. Yes it will accelerate, as all charged particles do in magnetic fields. Place a macroscopic magnetic dipole like a bar magnet in a uniform magnetic field and it will experience a torque, but no net force on its centre of mass. Put it in a non-uniform magnetic field and the centre of mass will accelerate with an increase in kinetic energy.

If an electron is put in a uniform magnetic field, it accelerates from the Lorentz force. Put it in a non-uniform magnetic field and does its kinetic energy increase like that of the bar magnet?