1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Magnetic Fields and total force

  1. Nov 29, 2006 #1
    Help!

    Given that B = (6x, -9y, 3z) find the total force experienced by a rectangular loop in the z = 0 plane:

    Loop defined as...
    1<x<3
    1<y<2

    with 5 Amp current flowing COUNTERclockwise.
     
  2. jcsd
  3. Nov 29, 2006 #2
    1) according to our guidelines, you need to show us what you have done
    2) what is the formula that you would use here ?
    3) are you sure you have all the data that you need ?

    marlon
     
  4. Nov 29, 2006 #3
    1) I guess I got a little anxious with the submit button!

    I'm having problems setting up the equation.

    2) I believe we're to use the equation: F = Int(dl x B) (where "x" indicated a cross product.)

    I know I need to apply superposition to the loop - doing the integral for each of the four sides of the loop.

    My problem comes from finding dl. Maybe I'm approaching the problem from the wrong angle. I initially thought you would use the integral relating B and the length of the loop in differential form.

    3) I've submitted all information given, but I'm unclear if there's an intermediate step to solve extra needed data.
     
    Last edited: Nov 29, 2006
  5. Nov 29, 2006 #4

    OlderDan

    User Avatar
    Science Advisor
    Homework Helper

    Sinde the field is constant, your integral reduces to a sum of four terms for the four sides of the loop, where each term is of the form (Bold is vector)

    F = I L x B
     
  6. Nov 29, 2006 #5
    With that analysis I keep getting the total resultant force as zero. Does this make any sense?
     
  7. Nov 29, 2006 #6

    OlderDan

    User Avatar
    Science Advisor
    Homework Helper

    What happens to the force when you reverse the current in a wire? You have pairs of opposite currents, so it absolutely does make sense. Torque would be a different matter.
     
  8. Nov 29, 2006 #7
    That's right! Thank you so much for the help!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Magnetic Fields and total force
Loading...