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Homework Help: Finding Resistance

  1. Dec 21, 2012 #1
    1. The problem statement, all variables and given/known data
    I need to find to resistance and am having problem as I do not know KCL's. All I know is the total resistance in series or parallel. I have attached the image. Find resistance b/w the 2 ends.

    2. Relevant equations
    If you have Resnik & Halliday open page 723(Vol2). and see figure 31-41. My question is same with r = 20ohm & R=10ohm.

    3. The attempt at a solution

    Attached Files:

    • 1.png
      File size:
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  2. jcsd
  3. Dec 21, 2012 #2


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    Staff: Mentor

    If you don't know the basic circuit laws it's going to be difficult to proceed; All you can do is try to apply "canned" formulas. Hint: Look up "Y-Delta transformation".
  4. Dec 21, 2012 #3


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    2017 Award

    Staff: Mentor

    One resistor has zero current inside due to symmetry, you can remove it and use your formulas for resistors in series/parallel afterwards.
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