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Homework Help: Inductance: Current in terms of Voltage

  1. Feb 7, 2009 #1
    I'm having a bit of trouble getting the right answer for a problem in my electrical engineering textbook. The question is:

    At t=0, the current flowing in a 0.6H inductance is 8A. What constant voltage must be applied to reduce the current to 0A at t=0.4s.

    I'm using the equation:

    [tex]i(t)=\frac{1}{L}\int\ v(t).dt+i(t_{0})[/tex] with limits 0.4s and 0s

    The answer i'm getting is 12V, and the book says 10V.. which is right??

    I'm using L=0.6H, i(t0)=8A, and i(t)=0A

    Please help!
  2. jcsd
  3. Feb 8, 2009 #2


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    It seems the book answer is wrong. And so is yours. The correct answer would be -12V.
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