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Homework Help: Thevenin AC circuit

  1. May 25, 2014 #1


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    1. The problem statement, all variables and given/known data

    Image Attached

    2. Relevant equations

    Thevenin, Series, Parallel

    3. The attempt at a solution

    j10(12-j34) / (j10+12-j34) = (340 + 120j) / (12/j24)

    1.67 + j13.3 or 13.44∠82.4°

    Now why can't I just use this equivalent resistance and multiply by the current source (22∠30°) to find the Thevenin Voltage? The result of doing this is 295.68∠112.8°V. Instead, the book uses Nodal Analysis to find VTH, which results in 295.3∠115.889°V.
    Why do the voltages roughly match, but the phase angles do not? Do you think book made mistake?

    Attached Files:

  2. jcsd
  3. May 26, 2014 #2


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    Staff: Mentor

    Your analysis looks okay. It's quite possible for a text to have a typo or mistake. If the book presents all the steps of their solution, perhaps you can spot where their error has occurred.
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