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Jump In The Capacitor Voltage?

  1. Oct 11, 2008 #1
    I know that voltage of a capacitor is continuous. However, I want to learn that; can it be a jump in the capacitor voltage? Also, if it is, how it can be happened?
  2. jcsd
  3. Oct 11, 2008 #2


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    Classically, to charge a capacitor requires current. To charge a capacitor in zero time requires infinite current, which is not possible. I could imagine that if the charging were very fast, it might be reasonable to approximate it as an instantaneous jump in voltage.

    But charge is quantized. I wonder what happens in the quantum mechanical case. :confused:
  4. Oct 12, 2008 #3
    charge on a capacitor is given by q = CV....there is superficially no time here ....BUT

    atyy's explanation is a good one: charge is the result of the flow of electrons which have have finite, not instantaneous speed....in fact charge in coulombs is given by q=it...amps times time....so in this formulation you can see...charging takes some "t".....

    in fact a step function (square wave) voltage will charge it really,really,fast.....but not instantaneously...

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