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Homework Help: Area of parallel plat capacitor

  1. Sep 23, 2010 #1
    1. The problem statement, all variables and given/known data
    The plates of a spherical capacitor have radii 31.0 mm and 43.0 mm.
    What must be the plate area of a parallel-plate capacitor with the same plate separation and capacitance of 12.4pF


    2. Relevant equations
    C=(epsilon*A)/d


    3. The attempt at a solution

    12.4*10^-12=(8.85*10^-12*A)/(.012m)

    so A=.0168m^2=1.68cm^2, which is incorrect?
     
  2. jcsd
  3. Sep 23, 2010 #2

    collinsmark

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    Gold Member

    0.0168 m2 ≠ 1.68 cm2.

    1 square meter does not contain 100 square centimeters. Rather it contains (100 [cm]) X (100 [cm]) = 10000 square centimeters.
     
  4. Sep 23, 2010 #3
    Yep lol, thanks, my answer was correct except for the conversion
     
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