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Homework Help: Electric Flux Leaving Surface

  1. Sep 20, 2011 #1
    1. The problem statement, all variables and given/known data
    A point charge of 20 nC is located at (4,-1,-3), and a uniform line charge of -25nC/m lies along the intersection of the planes x=-4 and z=6. (a) Calculate D at (3,1,0). (b) How much electric flux leaves the surface of a sphere of radius 5, centered at the origin? (C) Repeat part b if the radius of the sphere is 10.

    2. Relevant equations
    Q=total flux enclosed


    3. The attempt at a solution
    I've already solved part a without a problem but its b and c that are giving me trouble. I seem to be having problems with Gauss's law. A sphere of radius 5 seems like it would enclose the 20nC point charge so wouldnt electric flux simply equal 20 nC. The answer seems to be 0 though.
     
  2. jcsd
  3. Sep 20, 2011 #2
    You didnt calculate the line charge enclosed by the sphere.....
     
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