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Homework Help: EM - Capacitor -

  1. Feb 14, 2006 #1
    A circular parallel plate capacitor has plates of radius 0.1m; the plates are separated by 0.10 mm. A current is supplied to charge the capacitor. While charging, the potential difference across the capacitor increases by 10 V/μs.

    What is the magnitude of the rate of change of the electric field between the capacitor plates? Answer= 1 x 10^11 V/m.

    What exactly is the "rate of change of the electric field"? dE/dt? dΦ/dt? Φ?
    I have tried different methods using all three of those and have yet to receive the correct answer.

    I am using: ⌡E.dA = Q/ε for dE/dt
    and Φ= Q/ε for dΦ/dt and Φ
  2. jcsd
  3. Feb 14, 2006 #2


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    Staff: Mentor

    I get the correct answer. What is the equation for electric field, in terms of voltage and distance? You are given dV/dt, and the separation distance....

    Just watch your units and exponents.
  4. Feb 14, 2006 #3
    Wow! Thanks for the quick reply, I'm in urgent need right now.

    Thank you for the information, as it helped me get the right answer.
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