Finding north and south poles of an electromagnet

[Teachme]

So I have a question about an electromagnet. I understand the right hand rule, and how the magnetic field wraps around the wire, but I don't understand the location of the north and south poles. How do you determine where the north and south poles are since the magnetic field is a circle around the wire? Thanks

 

[Andrew Mason]

So I have a question about an electromagnet. I understand the right hand rule, and how the magnetic field wraps around the wire, but I don't understand the location of the north and south poles. How do you determine where the north and south poles are since the magnetic field is a circle around the wire? Thanks

Since the wire has to form a continuous loop you are only looking at only part of the magnetic field. The entire loop of wire will have a magnetic dipole moment that depends on the geometry of the loop. Not every magnetic field will resemble the field of a bar magnet, but every magnetic field will have a dipole moment. See: http://en.wikipedia.org/wiki/Magnetic_moment

AM

 

[Teachme]

Thanks!