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A Question about Magnetism

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RogerInHawaii

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All magnets are dipoles, their poles being identified typically as north and south. You can measure the strength of the magnetism with fairly simple devices, and you can even see a representation of the "lines" of magnetism with something as simple as iron filings. But I'm wondering, aside from bringing another magnet near to it, is there any way of determining whether a given magnetic field is a north pole or a south pole? In other words, what it is about a magnetic field that makes it a a north pole or a south pole? It's certainly not the strength of the field. I wouldn't think it's determined by the direction of the field, since both fields seem to "look" the same. What characteristic of a magnetic field gives it its south-ness or north-ness?
 
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neuvik

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RogerInHawaii":2cokzpi8 said:
All magnets are dipoles, their poles being identified typically as north and south. You can measure the strength of the magnetism with fairly simple devices, and you can even see a representation of the "lines" of magnetism with something as simple as iron filings. But I'm wondering, aside from bringing another magnet near to it, is there any way of determining whether a given magnetic field is a north pole or a south pole? In other words, what it is about a magnetic field that makes it a a north pole or a south pole? It's certainly not the strength of the field. I wouldn't think it's determined by the direction of the field, since both fields seem to "look" the same. What characteristic of a magnetic field gives it its south-ness or north-ness?
Assigning the poles are purely a form of convention. There is no way to tell them apart, apart from the convention we assign.
 
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MeteorWayne

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RogerInHawaii":czzk5byz said:
All magnets are dipoles, their poles being identified typically as north and south. You can measure the strength of the magnetism with fairly simple devices, and you can even see a representation of the "lines" of magnetism with something as simple as iron filings. But I'm wondering, aside from bringing another magnet near to it, is there any way of determining whether a given magnetic field is a north pole or a south pole? In other words, what it is about a magnetic field that makes it a a north pole or a south pole? It's certainly not the strength of the field. I wouldn't think it's determined by the direction of the field, since both fields seem to "look" the same. What characteristic of a magnetic field gives it its south-ness or north-ness?
The labels "North" and "South" are based on the alignment of the earth's current magnetic field and what we call them. They could just as easily be called "polka dots" and "unicorns". In any case, there are two different magnetic polarities, whatever they are called.
 
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origin

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RogerInHawaii":3aklty7x said:
But I'm wondering, aside from bringing another magnet near to it, is there any way of determining whether a given magnetic field is a north pole or a south pole? In other words, what it is about a magnetic field that makes it a a north pole or a south pole?
As pointed out this is rather arbitrary. But the field direction, by convention, of a bar magnet is from the south to the north trhough the magnet. Using the interactions of electric currents and magnetism is one way to determine the field direction. You can use the left hand rule - point your left hand like a little gun and your second finger pointing perpendicular to your pointer finger. If current is flowing through a wire in the direction of your second finger and if there is a magnetic field in the direction of your pointer finger there will be a force in the direction of your thumb.
 
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RogerInHawaii

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I do fully understand that the naming conventions for north and south are totally arbitrary. My question concerned the actual physical distinction btween the poles. Since "likes repel : opposites attract" there must be something different about them, something that actually distinguishes the one from the other.

The response from "origin" adressed my question, indicating that it is the field "direction" that distinguishes the two poles. So, thank you to origin.
 
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KhashayarShatti

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RogerInHawaii":13knvaio said:
is there any way of determining whether a given magnetic field is a north pole or a south pole? In other words, what it is about a magnetic field that makes it a a north pole or a south pole?
Yes there is. By electron. Deflection of moving electron in N is opposite to S. Which way, refer to left hand rule.
 
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