# Magnetic sphere , magnet properties

• sondreL
In summary, the conversation discusses the behavior of magnetic field lines in magnets and the potential effects of placing two half-sphere magnets near each other with a small gap between them. The fields would cancel out if the gap is closed, but if a bismuth circle is used to connect the two half-spheres, the reaction of conventional diamagnetic materials to magnetic fields is weak and there would be a higher field strength at the borders of superconductors.
sondreL
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.

sondreL said:
I ahve heard that also f a sphere would be made out of magnetic material the B field inside would also be zero

See Figure 6.8 on page 10 of this file, which shows the magnetic field produced by a uniformly magnetized sphere (is that the sort of thing you meant?):

http://physics.unl.edu/tsymbal/teaching/EM-913/section6-Magnetostatics.pdf

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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.

## What is a magnetic sphere?

A magnetic sphere is a spherical object made from a magnetized material, typically iron or steel, that has magnetic properties.

## What are the properties of a magnet?

The properties of a magnet include the ability to attract and repel other magnets, the presence of a north and south pole, and the ability to create a magnetic field.

## How does a magnetic sphere work?

A magnetic sphere works by aligning its magnetic domains in a specific direction, creating a magnetic field around it that can attract or repel other magnetic objects.

## What are the uses of a magnetic sphere?

Magnetic spheres have a variety of uses, including in scientific experiments, as educational tools, in magnetic levitation systems, and in medical devices such as MRI machines.

## Can magnetic spheres be harmful?

In general, magnetic spheres are not harmful to humans. However, strong magnets can interfere with medical devices such as pacemakers and should be kept away from these devices. Ingesting small magnets can also cause health problems, so they should be kept out of reach of children and pets.

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