How does the magnetic field alignment process work?

[mezarashi]

Hi everyone,

I have a question about the mechanics of the magnetic field alignment process. If you suddenly subject some iron filings to a magnetic field, they align along the magnetic field lines. I'd like to know how this happens step by step. I understand that the iron filings which were originally magnetically neutral need to magnetize and etc, although I can't seem to find a reason for that to happen.

I also did I search about this topic before posting and I found a really interesting debate that may be somewhat related from 2004 (very old by web standards) on magnetic fields and work. The accepted fact was that the magnetic field cannot do any work on a charged particle (as stated in multiple textbooks). However... a fluctuating magnetic field certainly can, as seen in induction motors or generators of all kinds. It is somewhat more complicated by the fact that the magnetic field appears to be a 'secondary' field created through moving charges (i.e. fluctuating electric fields). Then there was an unrelated debate about magnetic dipoles I am also addressing in another thread. I think there was also confusion about work concepts. In anycase, my conclusion is that a magnetic field can certainly "do work" on another magnetic element the same way mass can "do work" on another mass element through gravity and a charge can "do work" on another charge element through the electric force. What do you think?

 

[.:JimmY:.]

Iron exibits ferromagnetism, and a ferromagnetic material under an external magnetic field develops a strong magnetic dipole moment. so now there we have a magnetic field and a dipole, and force will certainly come along.
I'd not say that the magnetic field is a secondary field. As you said moving charge create magnetic field true enough, but also there we have some magnetic materials exibiting magnetic fields of there own like a bar magnet or a lodestone( i can't think of of anything else right now). Also as you might know changing magnetic field also generates electric field, as in EM wave propagation.
It certainly do work on a magnetic element.

 

[astrokreng]

I can provide a response to your question about the mechanics of the magnetic field alignment process. The process of aligning iron filings along magnetic field lines is a result of the interaction between the magnetic field and the magnetic moments of the iron particles. Magnetic moments are a measure of the strength and direction of a magnetic field, and they are present in all magnetic materials.

When a magnetic field is applied to a material, such as iron filings, the magnetic moments of the particles align themselves with the direction of the field. This is due to the fact that the magnetic field exerts a force on the magnetic moments, causing them to rotate and align with the field lines.

In simpler terms, the magnetic field acts as a guiding force for the magnetic moments in the iron filings, causing them to align in the same direction as the field lines. This alignment is what allows the iron filings to form a visible pattern, as they are all pointing in the same direction.

The process of magnetization, where a material becomes magnetic, is a result of the alignment of these magnetic moments. In the case of iron filings, the individual particles become magnetized when they align with the external magnetic field. This is why the filings can then attract or repel each other, depending on their orientation.

As for the debate about the magnetic field's ability to do work, it is important to differentiate between a static magnetic field and a changing magnetic field. A static magnetic field, as in the case of a bar magnet, cannot do work on a charged particle. However, a changing magnetic field, as in the case of an induction motor, can induce a current in a conductor and therefore do work on the charged particles within the conductor.

I hope this explanation helps to clarify the mechanics of the magnetic field alignment process and the role of magnetic fields in doing work.