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Prabhat
Prabhat
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How the potential energy of the dipole is $m.\vec{B}$ when work done by any magnetic field is 0Zero?

We know that magnetic fields don't do any work on ANY CHARGE from the form of Lorentz force we have here. But we still have magnetic dipole getting oriented by external magnetic fields. Now, intuition says that it has to be the currents in the magnetic dipoles which are causing some electric fields to get induced which in turn produces a magnetic field and so on. Something similar to this has come up in the past Is the work done by magnetic field always zero?. But the answer given here is very vague as to what really happens in microscopic physics. I want to know what exactly is happening in the view of classical electrodynamics and how the two pictures are not contradicting each other.

On The Side Note

I have faced similar problems before too in which I am comparing two pictures in electrodynamics and couldn't move forward without stamping out the assumptions of either of the theories/pictures. Like in this case, we have derived all the electromagnetism (I think!) from the point of view of a macroscopic world in which a constant current is driving the magnetic field. And the net charge inside such current flow is zero. All the microscopic interactions, on average, give rise to these macroscopic phenomena. So telling in some situations that you really have to go to sub-atomic to explain this phenomenon seems wrong. So, there shouldn't be any difference between microscopic and macroscopic physics as we took care of all those while averaging out.

How the potential energy of the dipole is $m.\vec{B}$ when work done by any magnetic field is 0?

We know that magnetic fields don't do any work on ANY CHARGE from the form of Lorentz force we have here. But we still have magnetic dipole getting oriented by external magnetic fields. Now, intuition says that it has to be the currents in the magnetic dipoles which are causing some electric fields to get induced which in turn produces a magnetic field and so on. Something similar to this has come up in the past Is the work done by magnetic field always zero?. But the answer given here is very vague as to what really happens in microscopic physics. I want to know what exactly is happening in the view of classical electrodynamics and how the two pictures are not contradicting each other.

How the potential energy of the dipole is $m.\vec{B}$ when work done by any magnetic field is Zero?

We know that magnetic fields don't do any work on ANY CHARGE from the form of Lorentz force we have here. But we still have magnetic dipole getting oriented by external magnetic fields. Now, intuition says that it has to be the currents in the magnetic dipoles which are causing some electric fields to get induced which in turn produces a magnetic field and so on. Something similar to this has come up in the past Is the work done by magnetic field always zero?. But the answer given here is very vague as to what really happens in microscopic physics. I want to know what exactly is happening in the view of classical electrodynamics and how the two pictures are not contradicting each other.

On The Side Note

I have faced similar problems before too in which I am comparing two pictures in electrodynamics and couldn't move forward without stamping out the assumptions of either of the theories/pictures. Like in this case, we have derived all the electromagnetism (I think!) from the point of view of a macroscopic world in which a constant current is driving the magnetic field. And the net charge inside such current flow is zero. All the microscopic interactions, on average, give rise to these macroscopic phenomena. So telling in some situations that you really have to go to sub-atomic to explain this phenomenon seems wrong. So, there shouldn't be any difference between microscopic and macroscopic physics as we took care of all those while averaging out.

Source Link
Prabhat
Prabhat
  • 672
  • 6
  • 17

How the potential energy of the dipole is $m.\vec{B}$ when work done by any magnetic field is 0?

We know that magnetic fields don't do any work on ANY CHARGE from the form of Lorentz force we have here. But we still have magnetic dipole getting oriented by external magnetic fields. Now, intuition says that it has to be the currents in the magnetic dipoles which are causing some electric fields to get induced which in turn produces a magnetic field and so on. Something similar to this has come up in the past Is the work done by magnetic field always zero?. But the answer given here is very vague as to what really happens in microscopic physics. I want to know what exactly is happening in the view of classical electrodynamics and how the two pictures are not contradicting each other.