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Solve by superposition method

  1. Jul 12, 2009 #1
    I'm solving by using superposition, I would like to ask that my solution is correct or not.

    By the way, the question is "Find v0"

    http://www.wisheyebio.com/uploads/Picture1.png [Broken]
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jul 12, 2009 #2

    cepheid

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    I don't know about superposition, but if you use KCL at the top node, you have three branches:

    The left branch has the current source and two resistors.

    The right branch has the voltage source and two resistors.

    The middle branch has the remaining resistor.

    KCL says that:

    current going into node = current coming out of node

    which, in this case means:

    current in left branch + current in right branch = current in middle branch.

    I called the current in the right branch i0, which makes v0 = i0R. I get a significantly different answer (-1.00 V), which I confirmed using a circuit-solving program.
     
  4. Jul 16, 2009 #3

    CEL

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    You made two mistakes in the second equation. Since [tex]i_x[/tex] is entering the plus sign of the voltage source, it should enter the equation as +9V, instead of -9V.
    Also, [tex]R + R + \frac{2}{3}R = \frac{8}{3}R[/tex], not [tex]\frac{32}{3}R[/tex]
     
    Last edited by a moderator: May 4, 2017
  5. Jul 16, 2009 #4

    Redbelly98

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    IIRC, when treating the 9V source you would replace the current source with an open circuit, not a short. So the 2/3 R was incorrect to begin with.
     
  6. Jul 16, 2009 #5

    CEL

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    You are right.
     
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