Question about magnetic flux density B

In summary: I'm not sure what that reason is.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... I'm not sure what that reason is.Maybe it has something to do with the Lorentz force? I'm not sure.Maybe it has something to do with the Lorentz force? I'm not sure.
  • #1
arul_k
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1
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?
 
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  • #2
arul_k said:
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.
 
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  • #3
Dale said:
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?
 
  • #4
arul_k said:
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.
 
  • #5
Dale said:
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?
 
  • #6
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.
 
  • #7
Dale said:
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...
 

1. What is magnetic flux density B?

Magnetic flux density B, also known as magnetic induction or magnetic field strength, is a measure of the strength of a magnetic field. It is defined as the amount of magnetic flux passing through a given area per unit area, and is measured in units of teslas (T).

2. How is magnetic flux density B different from magnetic flux?

Magnetic flux density B is a measure of the strength of a magnetic field, while magnetic flux is a measure of the total amount of magnetic field passing through a surface. In other words, magnetic flux density tells us the strength of the magnetic field at a specific point, while magnetic flux tells us the total amount of magnetic field passing through an entire surface.

3. What factors affect magnetic flux density B?

The magnetic flux density B is affected by the strength of the magnetic field source, the distance from the source, and the angle of the magnetic field in relation to the surface. It is also affected by the material the magnetic field is passing through, as different materials can have varying levels of permeability.

4. How is magnetic flux density B measured?

Magnetic flux density B can be measured using a device called a magnetometer, which detects the strength and direction of a magnetic field. It is also possible to calculate magnetic flux density using mathematical equations that take into account the factors that affect it, such as the distance from the source and the material it is passing through.

5. How is magnetic flux density B used in practical applications?

Magnetic flux density B is used in a variety of practical applications, such as in magnetic resonance imaging (MRI) machines, electric motors, and generators. It is also important in the design and construction of electronic devices, as it can affect the performance and functionality of these devices.

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