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Homework Help: Confused on this dielectric capacitance problem

  1. Jun 24, 2004 #1
    The electric field between the plates of a paper-separated (K=3.75) capacitor is 9.41E4 V/m. The plates are 1.75mm apart and the charge on each plate is 0.775E-6C. Determine the capacitance of the capacitor and the area of each plate?

    I got the voltage by V=Ed. and that came out to 164.675

    Where do i go from there because in order to get capacitance you need to know area, and finding the area of each plate is also a question in the problem. I thought about using C=Q/V, but that doesn't apply for dielectrics. Can someone helpme out?
  2. jcsd
  3. Jun 24, 2004 #2
    I think you should be able to use the fact that [itex]E = \frac{Q}{\epsilon_0A}[/itex]. This gives you an equation for the area which you can use to determine the capacitance.
  4. Jun 24, 2004 #3
    I tried that and that did not work out either, do you have anymore suggestions?
  5. Jun 24, 2004 #4

    Doc Al

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    Staff: Mentor

    Who says that C = Q/V doesn't apply for dielectrics? It's the definition of capacitance.
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