Magnetic fields attracting two disc-shaped magnets

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PlanTer254
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North pole and south pole attraction
I had 2 small magnets in my mouth for distraction while working on something else,and I had this wierd question.the two magnets were not that strong,so just a force was easy to separate them with my teeth.then they would attract to be attached to each other and then the question hit me,the 2 magnets would be attached to each other at a certain force,based on the strength of the magnetic fields...but a one magnet has both north and south poles,is it being attracted to the centre itself,based on the strength of the magnetic field?
 

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  • #2
Ibix
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I had 2 small magnets in my mouth for distraction
Dangerous. If you accidentally swallow them and they enter the coiled parts of your gut separately they can attract each other from adjacent coils and come together, pinching a bit of your gut between them. That cuts off the blood supply to the pinched part completely and kills it. You would need surgery urgently. Reference.
but a one magnet has both north and south poles,is it being attracted to the centre itself,based on the strength of the magnetic field?
I'm not sure I understand what you are asking. The north pole of one magnet is attracted to the south pole of the other with a force that depends on distance and alignment. Magnets with flat north and south poles and uniform magnetisation, like the disc shaped ones that are in everything these days, will generally try to align the centers of their circular faces, if that's what you are asking.
 
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  • #3
PlanTer254
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Dangerous. If you accidentally swallow them and they enter the coiled parts of your gut separately they can attract each other from adjacent coils and come together, pinching a bit of your gut between them. That cuts off the blood supply to the pinched part completely and kills it. You would need surgery urgently. Reference.

I'm not sure I understand what you are asking. The north pole of one magnet is attracted to the south pole of the other with a force that depends on distance and alignment. Magnets with flat north and south poles and uniform magnetisation, like the disc shaped ones that are in everything these days, will generally try to align the centers of their circular faces, if that's what you are asking.
Yes,they are disc shaped,I mean,is a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.
 
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PlanTer254
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Dangerous. If you accidentally swallow them and they enter the coiled parts of your gut separately they can attract each other from adjacent coils and come together, pinching a bit of your gut between them. That cuts off the blood supply to the pinched part completely and kills it. You would need surgery urgently. Reference.

I'm not sure I understand what you are asking. The north pole of one magnet is attracted to the south pole of the other with a force that depends on distance and alignment. Magnets with flat north and south poles and uniform magnetisation, like the disc shaped ones that are in everything these days, will generally try to align the centers of their circular faces, if that's what you are asking.
They are always on my teeth,and if they are not I will realize and noticed am being distracted by something else hence refocus on what I was doing, guess I better search something else for distraction...
 
  • #5
alan123hk
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Yes,they are disc shaped,I mean,is a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.

Are you talking about something like a solenoid inductor that when energized creates a compressive force on its own winding wires?
 
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PeroK
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a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.
There are no magnetic monopoles. That's what you are missing.
 
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  • #7
hutchphd
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Yes,they are disc shaped,I mean,is a single magnet has a North pole and south pole,which should be attracted to each other,but the stiffness of the material makes it not to collapse on it self,right or am I assuming something.
Here is a simplified answer. Each atom of the ferromagnet is itself a magnetic dipole. So if subdivided into atoms each atom will be roughly an independent "bar magnet" and interact with its neighbors. Smaller than that and it is much more complicated and of course there is more to it than this simple picture. The stiffness requires Quantum Mechanics.

And be very careful with supermagnets near toddlers for reasons already given. As soon as more than one is ingested the results can very bad indeed.
 
  • #8
PlanTer254
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Here is a simplified answer. Each atom of the ferromagnet is itself a magnetic dipole. So if subdivided into atoms each atom will be roughly an independent "bar magnet" and interact with its neighbors. Smaller than that and it is much more complicated and of course there is more to it than this simple picture. The stiffness requires Quantum Mechanics.
Are you talking about something like a solenoid inductor that when energized creates a compressive force on its own winding wires?
Like one found in earphones...was wondering if there is a force(magnetic) trying to make the material move,bend or flow in such a way to make the poles as close as possible,but it's not strong enough to break stiffness of the material,but if it is quantum stuff..am not there yet
 
  • #9
PlanTer254
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Like one found in earphones...was wondering if there is a force(magnetic) trying to make the material move,bend or flow in such a way to make the poles as close as possible,but it's not strong enough to break stiffness of the material,but if it is quantum stuff..am not there yet
Think of the material as a liquid, instead of solid... would it behave the same?
 
  • #10
hutchphd
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Think of the material as a liquid, instead of solid... would it behave the same?
I know of no simple answer (to what is a pretty interesting question). The only reason atoms do not collapse from from EM forces is because of quantum effects, so the rigid structure of everything is really what you are asking. The magnetic material is a solid consisting of domains. You don't need to understand the Quantum Mechanics to appreciate the structure
Here is a pretty good video:
 
  • #11
alan123hk
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Think of the material as a liquid, instead of solid... would it behave the same?
Taking the solenoid inductor as an example, when the current passes through its winding wire, a magnetic field will be generated, and N pole and S pole will be generated at the same time. But on the other hand, we can notice that the current flows in parallel between adjacent turns. When two wires are placed in parallel, the current flows in the same direction, and the wires attract each other, so there is a compressive force acting on the winding wire of the solenoid inductor.

But if you want to apply this concept to ferromagnets and permanent magnets, then the situation is much more complicated, and as mentioned in #7, you need to use quantum mechanics in this case.
 
  • #12
PlanTer254
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The magnetic material is a solid consisting of domains. You don't need to understand the Quantum Mechanics to appreciate the structure
Quantum mechanics is interesting,but one of those topics which require dedication to grasp...
 

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