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Finding equivalent resistance

  1. Feb 29, 2012 #1
    1. The problem statement, all variables and given/known data
    Trying to find equivalent resistance between points a and b.Dont know whether to include resistances r5 and r6.

    Thanks


    2. Relevant equations



    3. The attempt at a solution
    Im not sure what to do with the resistances r5 and r6in the open circuits are they apart of the calculations? i think they are not because nothing should be flowing threw them.
    without them i got 1.6 ohms for a equivalent resistance
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     

    Attached Files:

  2. jcsd
  3. Feb 29, 2012 #2

    berkeman

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    Staff: Mentor

    Welcome to the PF.

    Imagine connecting a resistance meter (DVM) between points a and b. That will put a voltage across those 2 points, which will cause currents to flow in some of the resistors. If points c and d are floating during this measurement, will there be any currents through R5 and R6?
     
  4. Feb 29, 2012 #3
    i want to say that there is no current through those wires, because their not connected to anything making them open circuits?
     
  5. Feb 29, 2012 #4

    gneill

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    Staff: Mentor

    If no current flows through a component then it will not contribute to the resistance.
     
  6. Feb 29, 2012 #5
    ok, but is there current flowing in r5 and r6
     
  7. Feb 29, 2012 #6

    gneill

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    Staff: Mentor

    Where would it flow to? You need a CIRCUIT (closed path) for current to flow.
     
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