Path of a conducting sphere through a uniform magnetic field

In summary, the question is whether a conducting sphere passing through a uniform magnetic field orthogonal to its direction of motion would be affected in terms of its path. The Lenz effect/Eddy currents would create a magnetic field opposing the orthogonal field, but it is unclear if this would cancel out and the sphere would continue moving unaffected, or if it would be pushed in the direction of the magnetic field, or if it would start spinning. However, the problem is not well-specified and without a specific question, there is no single correct answer. In the given scenario, the pure aluminum ball would experience vertical motion as it falls through the horizontal magnetic field created by two plate magnets, but it would end up with the same velocity as if there was no
  • #1
ccarleton
5
0
Hello, could someone help answer this question for me:
How would the path of a conducting sphere (i.e. AL) be affected as it passes through a strong uniform magnetic field orthogonal to the direction of motion.
I believe the Lenz effect/Eddy currents will create a magnetic field opposing the orthogonal field as it passes through it, but will every thing cancel out and the sphere continue to move in the same direction unaffected? Or will it be pushed in the direction of the magnetic field? Or will it just start spinning on its access or is there another scenario?

Thanks
 
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  • #2
The Eddy currents would slow the ball down but I can't think of any other effect that could make a neutrally charged object to deviate from a vertical path.
 
  • #3
Look for videos of a magnet falling (slowly) through a pipe. Now if the magnet is spherical shape, it's the same. If the falling object is not magnatized, but the pipe shaped object is, the result is the same.
 
  • #4
Thanks for the responses, I've seen those videos of the magnet falling through an aluminum tube. The reason I was wondering if this case would be different is because the magnet falling through the tube has the magnetic field wrapping around and hence has field lines going in the direction of motion. Would it be different in a situation with a uniform magnetic field where all field lines are orthogonal to the direction of motion?
 
  • #5
Anything that creates eddy currents, puts energy into the eddies and takes energy out of kinetic energy. So qualitatively, they're all alike. Quantitatively, I don't know.
 
  • #6
I don't think this problem is well-specified. Is the sphere moving from a zero field to a region initially at constant field? Is the sphere placed a region of constant field before the sphere is there and then the field lines allowed to become non-uniform due to the sphere? Is the sphere ferromagnetic or only conducting? Is the setup such that the field lines are uniform after the sphere is there? Without a very specific question there is no single correct answer,
 
  • #7
Vanadium 50 said:
I don't think this problem is well-specified. Is the sphere moving from a zero field to a region initially at constant field? Is the sphere placed a region of constant field before the sphere is there and then the field lines allowed to become non-uniform due to the sphere? Is the sphere ferromagnetic or only conducting? Is the setup such that the field lines are uniform after the sphere is there? Without a very specific question there is no single correct answer,

Thanks for the response Vanadium, for this scenario, the pure Aluminum ball would be in free fall, starting from an area with no magnetic field. it would then cross a uniform horizontal magnetic field created between two vertically mounted plate magnets. Then exit the magnet field as it continues falling. So the question is will there be any net vertical movement of the sphere.
 
  • #8
There will be vertical motion as it falls.

There will also be a small upward foce as it enters the field and a small downward force as it leaves, and it will end up with the same velocity as it would have had the field been zero.
 

1. What is the path of a conducting sphere through a uniform magnetic field?

The path of a conducting sphere through a uniform magnetic field is a circular path with a constant radius. This is because the magnetic force exerted on the sphere is always perpendicular to its velocity, causing it to continuously change direction.

2. How does the speed of the conducting sphere affect its path?

The speed of the conducting sphere does not affect its path in a uniform magnetic field. The radius of the circular path is only dependent on the strength of the magnetic field and the charge of the sphere.

3. What happens if the magnetic field is not uniform?

If the magnetic field is not uniform, the path of the conducting sphere will not be a perfect circle. The sphere will experience a net force in one direction, causing it to move in a curved path.

4. Can the conducting sphere's path be affected by the strength of the magnetic field?

Yes, the strength of the magnetic field directly affects the radius of the conducting sphere's path. A stronger magnetic field will result in a smaller radius, while a weaker field will result in a larger radius.

5. Does the mass of the conducting sphere have an impact on its path?

The mass of the conducting sphere does not have a significant impact on its path in a uniform magnetic field. This is because the magnetic force is dependent on the charge of the sphere, not its mass.

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