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Homework Help: Flux problem

  1. Jun 4, 2010 #1
    PREVIOUS POST ----https://www.physicsforums.com/showthread.php?t=165844
    THIS POST HELP ME OUT TO SOME EXTENT BUT I AM STILL MESSED UP.........

    I am messed up with the concept of projection of area of different surfaces and flux through different surfaces................

    Please someone explain it with some examples such as -

    1. Hemisphere (I AM GETTING --- FLUX = E pi r^2 ) PLEASE CONFIRM
    2. Frustum (not getting)
    3. Cone (not getting)

    we have to find flux through all these surfaces (The field E is uniform)
     
  2. jcsd
  3. Jun 4, 2010 #2
    sorry about my English ...
    - What came in must come out ....
    3.
    this is your Diagram:
    (N.B. the dots in the cone are just to give it shape)

    E
    -->.../.\
    -->../...\
    -->./.....\ <---- cone
    -->/____\___________ <- table

    ....
    E
    -->.../!
    -->../.!
    -->./..! <---- half cone
    -->/__! ___________ <- table
    you have a triangle so the flux is :(surface of triangle) * (E) = ....
    you can work out the same with othe problems .
     
  4. Jun 4, 2010 #3
    thanks for ur reply

    but can u please explain it for frustum and hemisphere

    not getting the answer in case of frustum

    and please confirm hemisphere one

    thanks
     
  5. Jun 5, 2010 #4
    What is the orientation of the hemisphere ?
    attachment.php?attachmentid=26240&d=1275727066.jpg
    case 1 :
    flux = (surface of semi Circle )*E
    or
    case 2 :
    flux = (surface of a Circle )*E
     

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    Last edited: Jun 5, 2010
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