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How to arrange given resistors in a given shape to meet target value?

  1. Sep 7, 2014 #1
    1. The problem statement, all variables and given/known data
    I have available resistors of 5 different values (10kΩ, 22kΩ, 47kΩ, 100kΩ and 220kΩ).
    How can I choose a combination of these resistors that will create a total resistance of 35kΩ in a U shape (using 5 resistors)?
    See attached picture of 'U' to get a clear picture of the shape.

    2. Relevant equations
    Series Resistors
    [R][/eq] = [R][/1]+[R][/2]+[R][/3]+...

    Parallel Resistors
    1/[R][/eq]=1/[R][/1] + 1/[R][/2] + 1/[R][/3] +...

    3. The attempt at a solution
    I really don't know here. They would all be in a series for the 'U' shape, so even if I use 5 of the 10kΩ resistors, I will end up with a total resistance of 50kΩ
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

    • U.PNG
      File size:
      777 bytes
  2. jcsd
  3. Sep 7, 2014 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    It would seem that since a simple series arrangement of the resistors does not give the desired total resistance of 35 k Ohms, you will need to explore an arrangement of resistors in parallel combined with resistors in series to see if a total R = 35 k Ohms can be established.
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