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Homework Help: Questions about circuits and Resistors

  1. Mar 6, 2010 #1
    1. The problem statement, all variables and given/known data

    http://www.sewanee.edu/physics/PHYSICS102/Ch28.pdf [Broken]
    On this link, can anybody explain to me how to set up problems 1-5?
    The answers are on the page, but I have no idea how to group the resistors together to find their equivalent resistance...
    Please ive been working on this for hours and i cannot figure it out

    2. Relevant equations


    3. The attempt at a solution
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Mar 6, 2010 #2
    resistors in series will be Rtotal = R1+R2+R3...
    resistors in parallel will be 1/Rtotal = 1/R1 + 1/R2 + 1/R3...
    Now look at question one for example, the resistor(2R) diagonally placed is in fact parallel to the 2 resistors with value of R bottom right and bottom, in turn these two resistors are in series.

    and finally the net resistance of this series and parallel combination is in series with the resistor (R) which is at the top.
    Now you can figure out what the net resistance is and you are done =) if you get confused try "redrawing" the circuit in a way you can visualize the series and parallel combinations.
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