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Homework Help: Leakage resistance in a capacitor

  1. Jan 15, 2009 #1
    1. The problem statement, all variables and given/known data

    I am trying to find the relevent equation to to solve the following problem,

    RL= leakage resistance measured across the dielectric

    A 100pF parallel-plate capacitor has a mica dielectric of relative permittivity [tex]\epsilon[/r]=12 and a resistivity of \rho=10^14\Omega m.

    I want to calaculate the leakage resistance of this capacitor.

    2. Relevant equations

    3. The attempt at a solution

    The previous question wanted to know the area and distance between the plates of the capacitor, i think that this has something to do with the answer to the question,

    I have solved this!!

    I think i have all the relevent information to have an atempt at the answer but dont know and cant find the equation,

    I am not sure if Resistance R = rhol/A has anything to do with it because it states resistivity is \rho = 10^14 \Omega m

    this has thrown me??

    I cant find anything that points me in the right dierction in my books or course work.
  2. jcsd
  3. Jan 15, 2009 #2


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    Homework Helper

    You're missing a needed formula here which gives you the capacitance of an ideal parallel plate capacitance. Use that and your resistance formula to find R.
  4. Jan 15, 2009 #3
    Hello Defender,

    Thanks for the reply, Im still not sure, i dont realy understand what you are on about? Im all mechanical ad never had to do electrical before.

    Are you on about C= epsilon r epsilon o * A / d

    If so, this is the formula for finding C which is in farads which i have already been given as100pF
  5. Jan 15, 2009 #4


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    Homework Helper

    You can transpose the formula to to obtain an expression to help you calculate resistance from the other formula.
  6. Jan 6, 2010 #5

    Did you ever get the formula as I am stuck on asimilar question
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