1. Limited time only! Sign up for a free 30min personal 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!

Finding the Force between a Straight Wire and a Triangular Current Loop

  1. Mar 25, 2012 #1
    1. The problem statement, all variables and given/known data
    A triangular loop of side length a carries a current I. If this loop is placed a distance d away from a very long straight wire carrying a current I', determine the force on the loop. See attachment for diagram.


    2. Relevant equations
    F=([itex]\mu[/itex]II'/2[itex]\pi[/itex]r)L
    F=I'LB
    B=[itex]\mu[/itex]I/2[itex]\pi[/itex]r
    3. The attempt at a solution
    I broke the calculation into three pieces. Force on the horizontal portion of the triangle, and the force on each of the two diagonal pieces.

    The force of the horizontal portion is just F=[itex]\mu[/itex]II'*L/2[itex]\pi[/itex]r

    dB=[itex]\mu[/itex]I dr/2[itex]\pi[/itex]r
    B=[itex]\mu[/itex]I/2[itex]\pi[/itex] [itex]\int[/itex]dr/r
    The distance from the wire carrying I' ranges from d to d+a/[itex]\sqrt{3}[/itex]. Thus, I set these as the limits of integration. Integrating I dr/r I get ln(r). Plugging this in with the appropriate limits, I get:
    B=([itex]\mu[/itex]I/2[itex]\pi[/itex])*(ln(1+a/d[itex]\sqrt{3}[/itex])

    Because both horizontal elements are equal, I will use the total length = a and combine these two forces:
    Diagonal Force=([itex]\mu[/itex]II'/2[itex]\pi[/itex])*(ln(1+a/d[itex]\sqrt{3}[/itex])

    Total force on the current element is the difference b/w the two forces:
    Total Force=([itex]\mu[/itex]II'/2[itex]\pi[/itex])*(a/d-(ln(1+a/d[itex]\sqrt{3}[/itex]))
    ??? Not sure what is wrong??? Please help and thank you!
     

    Attached Files:

  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: Finding the Force between a Straight Wire and a Triangular Current Loop
Loading...