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Homework Help: : Delta-Wye transformations

  1. Jan 25, 2013 #1
    URGENT: Delta-Wye transformations

    Hello there. In my electrical fundamentals class (a 201 level class), we just barely started Delta-Wye transformations. However, the homework that is due online tonight uses full transformations...confused, I have just tried to work through this using the book. I have become stuck...

    My homework is due tonight at midnight, so please help asap?

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

    All attached

    2. Relevant equations

    Ohm's law, and...I don't know the other ones

    3. The attempt at a solution

    I have worked through most of the solution in the jpg. However, I am stuck. I know I need to find I, because if I can find I, it would be very simple to use Ohm's law in the original circuit.

    I have tried to add the series and do parallel to leave

    16.87 + 9.62 || 55.5 = Rd

    then Rd || 36

    Then you are left with a simple circuit to determine I, which I calculated to be 4.4A.

    Can someone please help? haha
  2. jcsd
  3. Jan 25, 2013 #2
    Re: URGENT: Delta-Wye transformations

    Sorry, didn't attach the first time

    Attached Files:

    • plz.jpg
      File size:
      15.3 KB
  4. Jan 26, 2013 #3


    User Avatar

    Staff: Mentor

    Re: URGENT: Delta-Wye transformations

    Check the value that you obtained for Ra from the Y-Δ transformation; either it's not correct or something went wrong with combining it with the 29Ω resistor. Then continue to reduce the network until you're left with two resistances forming a voltage divider.


    Attached Files:

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