Question about magnetic flux density B

[arul_k]

Magnetic flux density B is a vector quantity and thus represents a force. However most texts state that the magnetic force is perpendicular to the direction of B, which is tangential to the magnetic field line at any give point. I assume that this magnetic force refers to the Lorentz force. So my question is:

1) What exactly does the direction of force B represent?

2) Would it be correct to state that it is the force B that acts on a test magnet causing it to orient along a magnetic force line?

 

[Dale]

Magnetic flux density B is a vector quantity and thus represents a force.

This is not correct. Not everything that is a vector represents a force. The B field in particular is not a force.

 

[arul_k]

This is not correct. Not everything that is a vector represents a force. The B field in particular is not a force.

Yes, I guess that was implied in the first part of the question. So what does the direction of B indicate?

 

[Dale]

Yes, I guess that was implied in the first part of the question. So what does the direction of B indicate?

It is the direction perpendicular to both the magnetic force and the current.

 

[arul_k]

It is the direction perpendicular to both the magnetic force and the current.

I've already mentioned that in my question! I wish to know what this "direction" of B represents?

 

[Dale]

That is all it represents. There is only one such line which is perpendicular to both the force and the current, and the B field direction identifies it. That is all, there is no more or less meaning.

 

[arul_k]

That is all it represents. There is only one such line which is perpendicular to both the force and the current, and the B field direction identifies it. That is all, there is no more or less meaning.

Interesting. So, why come up with the concept of direction of the B field at all?

There must be some reason why a test magnet aligns itself in the direction of the B field...