hope u can read this,,, well 5 years is not that LONG..
i was searching for concepts about the truth in the motion of compass along a wire with current. well, not expecting to be here but can't help to give my idea..
i think there is no S or N on the wire.....!!
to simply say,,, there is a LITTLE formation of this S and N on the wire....
know why,, well, because of the what they so called atoms....
the formation of this poles (S and N) is because of the motion of these electrical charges (nucleus and electrons). the movements produce the mag field around the wire. then, the field is affected by the current flowing through the wire resulting to changes in energy, so, the current's mag field is produce.... there is it... if you put the compass near the wire with current flowing through it, the compass is not pointing to the north, the compass needle points toward the direction of the current's mag field. well, if the wire really has a S and N ,try to stop the current from flowing through the wire, know what happens? the compass needle will not be pointing towards the current's mag field because there is no mag field anymore...... the time the current stops flowing, the mag field dies..... hehe, so i think there's no S and N on the wire.. it is formed!

wat do u think? hope this is right! hehe..
but, i am really puzzled in this phenomenon...

 

Hello clayandclay,

If the wire was made from soft iron you could probably magnetise it - though whether the current flowing in the wire would leave a residual magnetism is probably worth some speculation.....?

 

hi t_n_k

well yes, depends upon the property of the wire.......
coz i think there are things that are easy to be magnetized but there are not,, almost impossible...

 

This is a topic hijack, so I have moved it to its own thread.

Link to the original - http://forum.allaboutcircuits.com/showthread.php?t=744.

This probably properly belongs in the Physics section, so I will move it there.

Michael Faraday's experiments involving magnets and conductors would be pertinent to the subject above.

 

The wire by itself does not have an N or S pole - the field encircles the wire. Bend the wire into a loop to create N and S poles.

 

...making the field perpendicular to the axis of the wire.

 

Interestingly, a plasma can show some residual magnetism for a while. Some structures in the ionosphere are remarkably stable, considering they're less tangible than a gas!

eric