• Support PF! Buy your school textbooks, materials and every day products Here!

Magnetic fields etc

  • Thread starter hiljd
  • Start date
  • #1
1
0

Homework Statement



Not too difficult really, but I'm not understanding why two wires with identical currents running through them will move together. The question is, 'what happens when two parallel wires carry identical currents in oppsite directions?' But I dont understand what happens when they carry them in the same direction, so can't atempt this question.


Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
berkeman
Mentor
56,841
6,821
Thread moved from Advanced Physics to Intro Physics.

Start by drawing the magnetic field that circulates around the wire axis for each wire. Now, the electrons that are moving in a nearby wire will be affected by that circulating magnetic field in what way? Remember to use the right-hand rule to figure out the direction of the force on the moving electron charges in the magnetic field.
 
  • #3
JK423
Gold Member
394
7
The following will probably help you:
1)Ampere`s law
2)Laplace force + Right-hand rule
 
  • #4
312
0
http://www.physics4students.com/pages/dataDump/rightHandRule.jpg [Broken]
Take a look at the top picture. The magnetic field at a point to the right of the wire points into the screen. A bar magnet would have its north pole into the screen and its south pole out of the screen. If an identical second wire is placed to the right of that, its field would point into the screen. A bar magnet to the left of the second wire would have its south pole into the screen and its north pole out of the screen. Now we have 2 magnets arranged north-south and south-north, which will attract each other
 
Last edited by a moderator:

Related Threads on Magnetic fields etc

  • Last Post
Replies
7
Views
2K
Replies
4
Views
960
Replies
1
Views
935
Replies
3
Views
5K
Replies
0
Views
6K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
5
Views
2K
Top