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Magnetic field of a current loop

by B4ssHunter
Tags: current, field, loop, magnetic
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mikeph
#19
Sep27-13, 03:18 PM
P: 1,212
Magnets don't produce a magnetic field due to electrons being aligned, it's due to the magnetic dipoles being aligned. Magnetisation is defined as the volume density of magnetic dipoles.
B4ssHunter
#20
Sep27-13, 03:32 PM
P: 178
Quote Quote by Drakkith View Post
Magnetic field lines are not perpendicular to electric field lines, that's the magnetic and electric field vectors in an em wave. I could charge a magnet and have both types of lines come out of it on each end.
yes this has been confusing me , because in real life a magnet can attract an object in a direction parallel to the direction of the magnetic field * if the object is opposite to the north pole for instance , the direction of the magnetic field is so close to being parallel with the direction in which the force is applied to attract the object *
Drakkith
#21
Sep27-13, 06:21 PM
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Quote Quote by B4ssHunter View Post
yes this has been confusing me , because in real life a magnet can attract an object in a direction parallel to the direction of the magnetic field * if the object is opposite to the north pole for instance , the direction of the magnetic field is so close to being parallel with the direction in which the force is applied to attract the object *
What's confusing about it?
B4ssHunter
#22
Sep27-13, 08:48 PM
P: 178
Quote Quote by Drakkith View Post
What's confusing about it?
that attraction is perpendicular to the magnetic field , but as i mentioned before , at some points the attraction force is very close to being parallel to the magnetic force * like at points facing the north , south pole of the magnet * , so it was confusing for me
ehild
#23
Sep27-13, 10:38 PM
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Quote Quote by B4ssHunter View Post
i know that a current loop creates some kind of a short bar magnet ,
but how ?
Ask the opposite: how bar magnets can exist?

The bar magnets are created by atomic current loops. The electrons orbiting around the nuclei are like current loops, so some magnetic momentum can be assigned to the atoms: they behave as small "bar magnets". These interact and align with each other making magnetic domains. These domains can also aligned and you get a piece of magnet.

ehild
mikeph
#24
Sep28-13, 06:53 AM
P: 1,212
Quote Quote by B4ssHunter View Post
that attraction is perpendicular to the magnetic field , but as i mentioned before , at some points the attraction force is very close to being parallel to the magnetic force * like at points facing the north , south pole of the magnet * , so it was confusing for me
The Lorentz force is indeed perpendicular to the magnetic field, but the magnetic field in the proximity of the pole of a permanent magnet is very inhomogeneous, and any current loop by its nature has a finite dimension.

BxI will therefore point slightly towards or away from the centre of the bar magnet (but always perpendicular to B itself), and it is the vector sum of BxI over the loop itself which will point towards or away from the magnet.


Watch for 5 minutes from 11:56:

http://www.youtube.com/watch?v=SNDqAuxYOQ8&t=11m56s
B4ssHunter
#25
Sep28-13, 11:33 AM
P: 178
Quote Quote by mikeph View Post
The Lorentz force is indeed perpendicular to the magnetic field, but the magnetic field in the proximity of the pole of a permanent magnet is very inhomogeneous, and any current loop by its nature has a finite dimension.

BxI will therefore point slightly towards or away from the centre of the bar magnet (but always perpendicular to B itself), and it is the vector sum of BxI over the loop itself which will point towards or away from the magnet.


Watch for 5 minutes from 11:56:

http://www.youtube.com/watch?v=SNDqAuxYOQ8&t=11m56s
wonderful . thanks alot


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