Magnetic sphere , magnet properties

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Discussion Overview

The discussion revolves around the properties of magnetic fields in relation to magnets and magnetic spheres. Participants explore the behavior of magnetic field lines in various configurations of magnets, including infinitely long lines of magnets and the effects of cutting a magnetic sphere in half. The conversation includes theoretical considerations and hypothetical scenarios regarding magnetic interactions and field behavior.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants assert that magnetic field lines can exit from one magnet's N pole and enter another's S pole, while others clarify that this is true for isolated bar magnets only.
  • There is a discussion about the behavior of a magnetic sphere, with some participants questioning what constitutes a magnetic sphere and others suggesting that the B field inside does not have to be zero.
  • One participant references a figure illustrating the magnetic field produced by a uniformly magnetized sphere, seeking clarification on its relevance.
  • Hypothetical scenarios are presented regarding the arrangement of two half spheres, including the effects of a gap between them and the implications of using a bismuth connection, which is noted for its diamagnetic properties.
  • Some participants propose that the fields of two half spheres would nearly cancel each other out when close together, while others discuss the potential for field lines to form loops through a gap.
  • There is mention of superconductors as perfect diamagnetic materials, suggesting a different behavior in magnetic field strength near their borders compared to conventional diamagnetic materials.

Areas of Agreement / Disagreement

Participants express differing views on the behavior of magnetic fields in various configurations, with no clear consensus reached on several key points, particularly regarding the effects of gaps and the role of diamagnetic materials.

Contextual Notes

Some claims about the behavior of magnetic fields depend on specific configurations and assumptions that are not fully resolved in the discussion. The implications of using different materials, such as bismuth and superconductors, introduce additional complexity to the scenarios presented.

sondreL
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Hello , firs of all I know that every magnet has two poles ad the field lines exit one pole and enter into the other , now if we take a bunch of magnets , for simplicity assume an infinitely long line of magnets each separated by a distance , all of the magnets facing N-S N-S N-S , now do the field lines of the previous magnet exit and enter the poles of the same magnet or can the field lines say exit from the previous magnet's N pole and enter into the next magnets S pole? In other words if a magnets one pole is already attracted to a different magnet can the other pole field lines of the same magnet then go on to yet another magnet and so forth as long as each next magnet meets a new one for the field lines to go to ?

Now my second question is what happens in a magnet sphere ? Now I know that the E field inside a conducting sphere with a surface charge is zero and I ahve heard that also f a sphere would be made out of magnetic material the B field inside would also be zero , but what would happen if I had half a sphere in other words a permanent magnet sphere just cut in half , so that each side has a N and a S pole , assuming the inner sides are the N or S poles , I then put these half sides together but leave a tiny gap so that they don't touch physically , what would happen ? the two sides would be repelled constantly right? Say I hold them together with screws (non conducting ones) what happens , do I have a B field inside ? and is the line of the tiny separation a cusp ?
 
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Hello , firs of all I know that every magnet has two poles ad the field lines exit one pole and enter into the other
This is true for isolated bar magnets only.

now do the field lines of the previous magnet exit and enter the poles of the same magnet or can the field lines say exit from the previous magnet's N pole and enter into the next magnets S pole?
Yes they can (and do).

Now my second question is what happens in a magnet sphere ?
What is a magnet sphere?

I ahve heard that also f a sphere would be made out of magnetic material the B field inside would also be zero
It does not have to be zero.

If you split a regular magnet in half and separate the two parts by a tiny distance, you'll see a strong attraction between them.
 
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imagine the half sphere is a permanent magnet , could it be formed so that it's one pole is in the inside while the other is on the outside and what would happen if I placed two such half sphere close together in a way that would normally resemble a sphere only with a slight gap between them ? Would there be a monopole like magnetic field inside the volume enclosed by the half spheres ? Would the field lines come out through that small gap between them to form loops and if I would close the gap by putting these two magnetized half spheres the field would vanish right ?Because there would be no loops anymore

now imagine the same situation with the two magnetized or permanent magnet half spheres only this time the gap between them would be closed with a bismuth circle , in other words the two half spheres physically put together with a bismuth connection , what would happen then ? Bismuth is the best natural diamagnetic as I read , aka it expels b field lines so if I have two same polarity poles facing inwards but not touching each other magnetically or physically what would ahppen in such a situation ? Yes Jtbell I guess I am thinking about something similar to the paper you sourced
 

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sondreL said:
imagine the half sphere is a permanent magnet , could it be formed so that it's one pole is in the inside while the other is on the outside and what would happen if I placed two such half sphere close together in a way that would normally resemble a sphere only with a slight gap between them ?
The fields would cancel nearly completely (and completely if you close the gap).

Would the field lines come out through that small gap between them to form loops and if I would close the gap by putting these two magnetized half spheres the field would vanish right ?Because there would be no loops anymore
Right.

now imagine the same situation with the two magnetized or permanent magnet half spheres only this time the gap between them would be closed with a bismuth circle , in other words the two half spheres physically put together with a bismuth connection , what would happen then ? Bismuth is the best natural diamagnetic as I read , aka it expels b field lines so if I have two same polarity poles facing inwards but not touching each other magnetically or physically what would ahppen in such a situation ? Yes Jtbell I guess I am thinking about something similar to the paper you sourced
The reaction of all conventional diamagnetic materials to magnetic fields is quite weak.
You can use superconductors, they are perfect diamagnetic materials. Then you'll see a higher field strength close to the borders of those superconductors.
 

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