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Dielectric Polarization Components in Ideal RC and C circuits

  1. Sep 2, 2014 #1
    Hi, I would like to know what the theoretical implication is, as it pertains to RC circuits of the following hypothetical situation(s):

    If one were to connected an ideal discharged capacitor in parallel with an ideal voltage source with zero resistance in the loop, the calculated RC time constant would be 0s.

    1.) Does this imply instantaneous charging of the capacitor? If so, does it mean the dielectric also polarizes instantaneously. (discontinuity in the dipoles alignment trajectory)

    2.) One can view the RC time constant as the time required to charge the capacitor, through the resistor, by ≈ 63.2 percent of the difference between the initial value and final value of voltage applied.

    If the resistance were removed, there would still seems to be a "separate" and "independent" dielectric polarization time component that is not due to the restriction imposed by a series resistance. Is there a separate time constant (independent of RC) for the time it takes the dielectric to fully polarize or is there a better way to think about this?

    Note: I tend to think of charging a capacitor as two separate superimposed mechanisms. The first by the charge action on the capacitor due to a restriction by a resistance R and governed by the resulting RC time constant. (Rate at which charge may accumulate)

    The second by the polarization reaction of the E-field "in the dielectric" that opposes the E-field of the charge accumulation on the plates, and causes more charge to accumulate. (Rate at which the dielectric polarizes)

    3.) Is storing charge on a capacitor synonymous with storing energy in the capacitor?

    Please help me clarify any misbeliefs, superstitions, etc.. Thanks!
  2. jcsd
  3. Sep 4, 2014 #2
    Any takers? I haven't got any replies yet, wondering if I am missing any information or if what I have posted is not clear enough or too abstract. Feedback would be appreciated. Thanks again.
  4. Sep 4, 2014 #3


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    This question is related to a thread on the EE forum

    If you are including some characteristic of the dielectric then this is supplying the necessary series R to take the situation away from the ideal 'zero time constant' and the problems associated with that.
    AS for Q3, Charge and energy are not the same things. E = QV. The energy is related to the PD as well as the charge imbalance.
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