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Homework Help: Biot-Savart Law (infinite filament)

  1. Oct 25, 2008 #1
    An infinite current filament carries a current of 3A and lies along the x-axis. Using Biot-Savart Law, find the magnectic field intensity in cartesian coordinates at a point P(-1,3,2).

    dH = I vec{dl} x hat{R} / 4piR^2

    let substitude hat{R} with vec{R} / R

    then dH = I vec{dl} x vec{R} / 4piR^3

    vec{R} = hat{x}(-1-x) + hat{y}3 + hat{z}2 and vec{dl} = hat{x}dx

    vec{dl} x vec{R} =
    |hat{x} hat{y} hat{z}|
    | 1 0 0 |
    | (-1-x) 3 2 |

    =[hat{y}-2 + hat{z}3] dx

    dH = (I)(dx)(hat{y}-2 + hat{z}3) / 4piR^3

    magnitude of R = sqrt [(-1-x)^2 + 3^2 + 2^2]

    dH = (I)(dx)(hat{y}-2 + hat{z}3) / 4pi[(-1-x)^2 + 3^2 + 2^2]^3/2

    how do I solve for the next step? thanks!
     
  2. jcsd
  3. Oct 25, 2008 #2
    You should integrate each component of the field.
     
  4. Oct 26, 2008 #3
    I dont know how to integral since it is very complicated.
     
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