Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Current Sheet - Amperes Law

  1. Apr 4, 2008 #1
    1. The problem statement, all variables and given/known data

    Consider an infinite sheet of parallel wires. The sheet lies in the xy
    plane. A current I runs in the y-direction through each wire. there are
    N/a wires per unit length in the x direction. Write an expression for B(d)
    the magnetic field a distance d above the x y plane of the sheet and we
    have to express the magnetic field as a vector.

    2. Relevant equations

    Ampere's Law --> closed integral of (Bdl) = uIencl

    3. The attempt at a solution

    I know that by using the right hand rule, the magnetic field would
    pointing in the negative x direction if i pick a point above the surface.
    Then I tried to figure out what Iencl is and I get I = (N/a)(a)(I) = NI
    Then using ampere's law I get

    B(top integral + bottom integral) = uNI
    B(2a) = uNI
    B= UNI/2a
    and since the magnetic field is heading towards the negative x direction
    I typed in B = -(uNI)/2a x

    Please help! I don't know what I'm doing wrong! Thanks!
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

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