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Homework Help: Physics Homework problem: Dielectrics

  1. Mar 17, 2009 #1
    I cannot figure out this problem...can someone help me???

    A 3500 air-gap capacitor is connected to a 32 battery.

    If a piece of mica fills the space between the plates, how much charge will flow from the battery?

    Express your answer using two significant figures.
  2. jcsd
  3. Mar 18, 2009 #2


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    Welcome to PF!

    Hi Jscrub! Welcome to PF! :wink:

    First, how much charge will flow from the battery when the gap is just air?

    Second, what equations do you know about how a dielectric affects a field or a capacitor? :smile:
  4. Mar 18, 2009 #3
    c= KCo


    Q Air = 1.12E-4
  5. Mar 18, 2009 #4
    v= 32 V

    K(mica) = 7

    K (air) = 1.0006

    so, Co= 1.12E-4
  6. Mar 18, 2009 #5


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    What is a 3500 air-gap capacitor?

    Is that a 3500μf capacitor or 3500nf?

    What is the effect of the dielectric on the capacitance?

    I don't follow your conclusion
    Haven't you added a dielectric to your capacitor?
  7. Mar 18, 2009 #6
    The above was not a conclusion..it was just a reply to the previous person...

    Co = 3500E-9...

    But it is fine..I don't need anymore help...I figured it out...

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