Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question about Dielectrics

  1. Feb 6, 2010 #1
    I'm reading my physics textbook right now and it states that when you add a dielectric between two capacitors you are:
    1. Increasing the potential difference between the two plates.
    2. Increasing capacitance by decreasing V (Q/V=C)

    Isn't this contradictory? I thought that V in the equation (Q/V=C) was the potential difference between the capacitor plates. Therefore, if you decrease V, you woul be lowering the potential difference between the plates, not increasing it. Can someone explain this to me? Thank you.
     
  2. jcsd
  3. Feb 6, 2010 #2
    It is contradictory.
    The effect of inserting a dielectric material between the plates of a charged capacitor, is to reduce the pd between those plates. (Charge stays constant)
    This has the effect of increasing the capacitance.
    C=Q/V so if you decrease V you increase C.
    It must be a misprint.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook