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Homework Help: Calculating power in a circuit with loops

  1. Nov 12, 2009 #1
    1. The problem statement, all variables and given/known data
    http://img33.imageshack.us/img33/1147/question1x.jpg [Broken]

    2. Relevant equations

    V = IR, Sum of currents at junction = 0.

    3. The attempt at a solution

    Just doing some exam revision, and found this one in my notes. I'm not really sure how to go about it. Using Kirchhoffs rules, you obviously end up with three variables, and can't solve the equations:

    10 - 10I(1) - 20I(2) = 0
    15 - 20I(2) - 10I(3) = 0

    So I don't know how to calculate the current for any loop on the circuit, since they all have two components. Anyone got any pointers? Thanks!
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 12, 2009 #2


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    Homework Helper

    Take I(2) = I(1) + I(3) and solve the equations.
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