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Homework Help: Find the flux passing through the plane

  1. Mar 5, 2007 #1
    1. The problem statement, all variables and given/known data
    A linear charge pl=2.0microC/m lies on the y-z plane.from[0 -1 1] to [0 1 1]. Find the flux passing through the plane extending from 0 to 1.0m in the x-dir and -infinity to +infinity in the y direction.
    ***i wrote this in matlab and got 0.5micro as answer***

    2. Relevant equations
    Q = gauss law.
    where D = pl/(2*pi*rho) , rho (distance from line to sheet).

    3. The attempt at a solution
    I found D = 0.32 micro C/m^2. But how do i consider the area so that i can multiply with D to get the flux ( i am assuming no integration required in this case becase the flux is perpendicular to the sheet..
    Any help would be appreciated...
     
  2. jcsd
  3. Mar 5, 2007 #2

    Meir Achuz

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    This is a harder problem than you think.
    The D field from a finite length wilre has to be used,
    not the formula you have for D.
    You can't use Gauss.
     
  4. Mar 5, 2007 #3
    i thought i need to use Gauss' Law[(integral)D.ds] to find the flux through the entire surface.Then for finding the D for the finite wire what do i do? i am confused..
     
  5. Mar 5, 2007 #4
    I saw in the text book the charge on the line can be also calculated as pL*L which gives me 4 micro C.But i don't if i use this inorder to solve the problem or not..
     
  6. Mar 5, 2007 #5

    Meir Achuz

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    You have to integrate Coulomb's law for a finite length.
    It is like the integral for an infinite length, but with finite limits.
     
    Last edited: Mar 5, 2007
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