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Homework Help: What is the charge that can be stored on this capacitor

  1. Jul 17, 2008 #1
    1. The problem statement, all variables and given/known data

    A parallel-plate capacitor has dimensions 3.5cm x 5.2 cm. The plates are separated by a 1.1-mm thickness of paper (dielectric constant k = 3.7). What is the charge that can be stored on this capacitor, when connected to a 1.5-V battery? (E0 = 8.85 x 10^-12 C^2/Nm^2)

    2. Relevant equations

    C=Keo(A/d)
    Qmax=(Cdelta)Vmax

    3. The attempt at a solution


    C=Keo(A/d)
    =3.7(8.85E-12)(18.2E-4/1.1E-3)
    =200E-12 F

    Qmax=C(deltaVmax)
    =(200E-12)(1.5V)
    =300E-12 C

    300E-12 C does not seem like the right answer
     
  2. jcsd
  3. Jul 17, 2008 #2

    alphysicist

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    Homework Helper

    Hi ziplock2k,

    I don't think those numbers give 200e-12 F.
     
  4. Jul 17, 2008 #3
    C=Keo(A/d)
    =3.7(8.85E-12)(18.2E-4/1.1E-3)
    =54.18E-12

    Qmax=C(deltaVmax)
    =(54.18E-12)(1.5V)
    =300E-12 C

    81.27E-12 C

    Is my new calculations right?
     
  5. Jul 17, 2008 #4

    alphysicist

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    Homework Helper

    That last number looks right to me.
     
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