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-   -   Wire does a loop of wire create a norh pole and a south pole (http://www.physicsforums.com/showthread.php?t=246029)

sameeralord Jul21-08 07:11 AM

Wire does a loop of wire create a norh pole and a south pole
 
Hello everyone,

I just read that in a loop of wire if the current is anticlockwise that part is a north pole. I'm just wandering what do they mean by this. I thought only magnets have north poles. Any help would be appreciated. Thanks :smile:

runningman97 Jul21-08 07:29 AM

Re: Wire does a loop of wire create a norh pole and a south pole
 
Sounds like it's talking about an electromagnet, where a coil of current carrying wire creates a magnetic field the same as that of a bar magnet, with a north and south pole. Looking end on to the electromagnet, the north pole will have an anticlockwise current and the south pole will have a clockwise current.

Domenicaccio Jul21-08 08:24 AM

Re: Wire does a loop of wire create a norh pole and a south pole
 
Quote:

Quote by sameeralord (Post 1808480)
Hello everyone,

I just read that in a loop of wire if the current is anticlockwise that part is a north pole. I'm just wandering what do they mean by this. I thought only magnets have north poles. Any help would be appreciated. Thanks :smile:

A loop of wire with current and a magnet are very similar from the point of view of their behaviour in an electric field.

It may help to thinkg of "poles" as just an abstraction and not something as "solidly real" as having shape and extension. In fact, the north and south poles are not localized entitities, but rather just "directions". A magnet has an "up" and a "down", and so does a loopwire with current: "up" or "north" is the side of the wire you're looking at when you see the current going counterclockwise. A magnet also has a current flowing on its side surface, so when you look at it from the "north" side you see the side surface current flowing counterclockwise as well.


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