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Homework Help: Magnetic Field due to a current loop

  1. Mar 3, 2008 #1
    [SOLVED] Magnetic Field due to a current loop

    1. The problem statement, all variables and given/known data

    A single loop of wire of radius 3 cm carries a current of 2.6 A. What is the magnitude of B on the axis of the loop at 2 cm?


    2. Relevant equations

    B=[tex]\mu[/tex]/(4[tex]\pi[/tex]) * 2[tex]\pi[/tex](R^2)*I/(z^2+R^2)^(3/2)



    3. The attempt at a solution
    I = 2.6 A
    R = .03 m
    z = .02m

    I calculate .000031 T
    It should just be a simple matter of plugging in numbers, but every time I use this equation it ends up being wrong. If anyone could tell me what I might be doing wrong it would be greatly appreciated.
     
  2. jcsd
  3. Mar 3, 2008 #2

    Doc Al

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    Staff: Mentor

    Looks OK to me. Why do you think it's wrong?
     
  4. Mar 3, 2008 #3
    It is computerized homework, so when I put in the answer that I calculated it keeps telling me that it is wrong. I have done the same thing with multiple different distances, and they all come up wrong, so I believe that it is something that I am doing, I am just not sure what
     
  5. Mar 3, 2008 #4

    Doc Al

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    Staff: Mentor

    Those online systems can be flaky. I don't think you're doing anything wrong. Your equation is correct and your answer is correct.

    Things to check: Are you sure they want the answer in Teslas? How many sig figs does the system like?
     
  6. Mar 3, 2008 #5
    I finally figured it out. It turns out that the system decided it wanted it in scientific notation. Thanks for your help!
     
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