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Homework Help: Voltage in a circuit

  1. Feb 28, 2010 #1
    1. The problem statement, all variables and given/known data

    http://img696.imageshack.us/img696/7609/circuit.jpg [Broken]

    2. Relevant equations



    3. The attempt at a solution

    I know that the answer of the question below is D, but how do I get to that answer?

    My guess would be to use current divider to find the current going through v0 then we can calculate v0 then divide by is.

    When I do that I got a very complicated result...

    My calculations for the current divider is to find the equivalent resistance in the circuit, which is:

    R1R2/R1+R2 || R1R2/R1+R2
    which is R1R2/2R1+2R2

    Then after calculating the v0/is I got R1R2/2(R1+R2). This doesn't seem to match the answers above
    is this approach correct so far?
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 28, 2010 #2

    rl.bhat

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    Homework Helper

    Vo/Is is the resistance. It does not depend on the branch current. The current in the circuit is Is. Vo is the same for R1 and R2.
    So what is Vo across that branch? Convert the equivalent resistance into G to get the required answer.
     
  4. Feb 28, 2010 #3
    the equivalent resistance is this:

    R1R2/2R1+2R2
     
  5. Feb 28, 2010 #4

    rl.bhat

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    Homework Helper

    From where did you get 2?
    The resistance of desired branch is [tex]\frac{1}{G_{}1+G_{}2}[/tex]
     
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