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Homework Help: Balanced Wheatstone Bridge

  1. Oct 3, 2012 #1
    1. The problem statement, all variables and given/known data
    10icak0.jpg

    Show that the current in the middle is zero if all the resistors are equal


    3. The attempt at a solution

    KVL for left and right:
    V - R*i1 - R*i2 = 0
    V - R*i3 - R*i4 = 0

    i1 + i2 = i3 + i4

    KCL:
    i1 + i3 = i2 + i4
    i1 + iG = i2
    i3 = iG + i4

    I must prove that i1 = i2 or i3 = i4 but all I get is i1 = i4 and i2 = i3 combining KVL and KCL
     
  2. jcsd
  3. Oct 3, 2012 #2
    For the current in the middle to be zero, points A and B are at the same potential.
     
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