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Homework Help: Y/Delta Circuit Problem

  1. Sep 7, 2010 #1
    1. The problem statement, all variables and given/known data
    [PLAIN]http://img38.imageshack.us/img38/1620/halpwd.jpg [Broken]

    2. Relevant equations
    I've been simplifying the circuit but with no real objective or guidance. I just don't know how to even begin to show that R and RL are equal. Can someone please help me?

    3. The attempt at a solution
    This is my work so far. I've just tried simplifying it, but like I said I have no real idea what to do next.
    http://img706.imageshack.us/img706/6398/imggc.jpg [Broken]
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 7, 2010 #2


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    Homework Helper

    You have already converted Y to Δ.

    After simplification, new Δ consists of 3R, 3R/4 and 3R.

    Again convert Δ to Y. Three sections contain R/3, R/3 and 4R/3.

    So Rab = RL = R/3 + [4R/3*(R/3+RL)]/(R/3 + 4R/3 + RL)

    Simplify the equation.
  4. Sep 7, 2010 #3
    Wow, thanks a lot!
  5. Sep 8, 2010 #4
    Does anyone know how I can get part B?
  6. Sep 8, 2010 #5


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    Homework Helper

    Total current I = vi/R.

    Current through c-d branch is

    T2 = I*(4R/3)/2*4R/3 = I/2

    vo = R*I/2 = vi/2
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