Detecting lorentz force

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  • #1
Samson4
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I setup an experiment to detect a magnetic field due to the Lorentz force acting on a current. It is a hollow conducting cylinder with a magnet at one end. With current flowing in the cylinder I approach the negative end with the north pole of the magnet. Using the left hand rule I expected the current to flow in a counterclockwise spiral resulting in a magnetic field through the solenoid. The solenoid inside the cylinder should experience a changing magnetic field but this does not happen. Why is this not working? I'm using a very strong neodymium magnet.
hollow conductor.jpg
 

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  • #2
kuruman
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What do you think the current through the hollow cylinder does? Your drawing shows the current running parallel to the cylinder's axis. If that's the case, it provides no field inside it, so what is its purpose? What did you use to measure the effects of a changing magnetic field through the solenoid? Was it sensitive enough? In experiments of this sort, one needs not only a strong magnet, but also a solenoid of many turns, at least a few hundred. If you really are trying to measure the Lorentz force and not the induced emf, how is your setup going to achieve this goal?
 
  • #3
Samson4
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I think the current is running parallel to the axis before the lorentz force produces a spiral path in the current flow. I used a N45 and N52 neodymium magnet and got zero results. Then I used a coil of 150 turns instead of the magnet and tried a 10khz frequency to try and detect something. I was trying to measure a magnetic field propagating through the cylinder away from the end where the magnetic field is supplied. The solenoid had 590 turns of 34 awg wire. I've tried applying the magnetic field with the power on and off to be able to differentiate between induced emf and a magnetic field produced by the spiraling charges.

With the power off/on or the cylinder absent altogether; I don't notice any difference in the output of the solenoid when using a voltmeter or with the solenoid connect to a pair of sensitive headphones.
 

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