Exploring the Hall Effect: Can a Magnetic Field Induce a Potential Difference?

[aaaa202]

The idea behind the Hall effect is according to my book that the magnetic field induces a charge distribution such that there is more positive charge on one side and more negative on the other. This induces a potential difference. But the question is: Is this the correct way to view it? I mean after all the charges are never stationary and even so, how is it possible for a magnetic field, which can do no work, to establish a potential difference?

 

[universal_101]

Magnetic Field is not doing any work, it merely changes the direction of motion of moving electrons and holes. Just as a curved slide > _/ would throw any object upwards if the object come running towards it, without ever doing any work(by slide), you would find the object's potential energy increased(in gravity). And this potential can be maintained if you keep trowing objects towards the slide. (same as electrons continuously going in magnetic field)

 

[Bobbywhy]

Here is an excellent explanation of how a Hall effect sensor works:
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html

It may be of interest that a commercially available Hall-effect sensor that can measure the earth’s magnetic field exist, and connect directly to your laptop, etc.

Magnetic Field Sensor
http://www2.vernier.com/booklets/mg.pdf

 

[sophiecentaur]

If the hall device is already there and switched on, the action of turning on the magnetic field will require a small but finite amount of energy extra than if the device were not switched on. This is a 'one off' input of energy, though and not an ongoing requirement for extra Power to be supplied by the magnet coils.

 

[PJC01]

The Hall effect is a well-studied phenomenon in which a magnetic field applied perpendicular to an electric current causes a potential difference to develop across the material. This is due to the Lorentz force, which acts on the moving charged particles in the material and causes them to deviate from their original path.

In response to the question posed, it is important to note that the charges in the material do not need to be stationary for the Hall effect to occur. As long as there is an electric current flowing through the material, the Lorentz force will act on the charges and cause a potential difference to develop.

Furthermore, while it may seem counterintuitive that a magnetic field, which is unable to do work, can induce a potential difference, it is important to remember that the magnetic field is not actually doing the work. The work is being done by the electric field that is created due to the separation of charges caused by the Lorentz force. This electric field is responsible for the potential difference across the material.

In conclusion, the Hall effect is a well-understood phenomenon and the concept of a magnetic field inducing a potential difference is a valid way to view it. While the charges may not be stationary and the magnetic field may not do work, the resulting potential difference is a result of the Lorentz force and the resulting electric field.