Electromagnets and pole shifting

[Mr_Bojingles]

I read a couple of tutorials on electromagnetism and solenoids but there's a good few questions left unanswered.

1.) What determines the poles of a solenoid electromagnet? Let's say I have direct current flowing from the left end of the coil to the right. Will the north pole automatically be on the left end of the solenoid or the other way around?

If I turn the battery around will that reverse the poles?

2.) Say I have a long circuit with the wires places side by side so the two wires run parallel. Let's say there's a heavy current running through the circuit.

Battery================Resistor

Since there's a small magnetic field surrounding the wire through the whole circuit and the wires are close enough that their magnetic fields overlap. Would it create 2 poles one at the battery end and one at the resistor end?

 

[Danger]

This site might cover everything that you want to know. I didn't check it all out, but the beginning is good. Your 2-wire problem, as far as I know, isn't a problem at all. If they are following the same path, they essentially act as one larger wire. That's how stranded cables work.
http://library.thinkquest.org/13526/c3c.htm"

 

[NoTime]

1) Depends on which way the coil is wound.
Look up the right hand rule.

1A) Yes.

2) What does the field look like around a single wire?
Using the right rule, what is different about the field on wire A and the field on wire B.
What do you think happens when you overlap the two fields?

 

[NoTime]

Your 2-wire problem, as far as I know, isn't a problem at all. If they are following the same path, they essentially act as one larger wire. That's how stranded cables work.
http://library.thinkquest.org/13526/c3c.htm"

The current will be going in one direction in one wire and the reverse direction in the other wire.
If the current was going the same direction in both wires then you would be correct.

 

[Danger]

Ooops! Sorry, I misunderstood the question. I didn't realize that he meant that the second wire was the return path.