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Electric flux

  1. Mar 11, 2010 #1
    Why the electric flux [tex]\Phi[/tex] is defined as EAcos[tex]\theta[/tex]?

    I don't understand the part about cos[tex]\theta[/tex].....
  2. jcsd
  3. Mar 11, 2010 #2


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  4. Mar 11, 2010 #3


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    Welcome to PF!

    Hi yaik! Welcome to PF! :smile:

    Imagine you want to know the flux of bugs flying horizontally along a road.

    If you count the number that go splat on your windscreen, then you'll collect less (in a given time) if the windscreen is tilted: the number will be greatest at 90º, and zero at 0º: it'll be proportional to cosθ. :smile:

    Mathematically, flux of a field E through a surface with area A is E.(Añ), where ñ is the unit vector normal (perpendicular) to the surface. :wink:
  5. Mar 12, 2010 #4
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