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Homework Help: Dielecric Thickness

  1. Jan 6, 2010 #1
    1.
    A capacitor is formed by 2 parallel plates seperated by a dielectric of relative permattivity er = 12, the capacitor plates are 5mm x 10mm. Calculate the thickness of the dielectric required to create a capacitor of 100pF




    2. C = eA / d therefore d=eA/C, we have C 100 x 10-9, area of pates 5x10-3 x 10x10-3 = 50x10-3mm2 (0.05m2



    3. C = eA / D = 12 x 0.05 / 100 x 10-9
    = 6000000
    This is a massive figure so I am guessing incorrect any pointers
     
  2. jcsd
  3. Jan 6, 2010 #2

    Should I have used d = Eo x Er x A / C

    12 x 8.85x10-12 x 50 x 10-3 / 100 x 10-9 = 5.31x10-5 = 0.0513mm
     
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