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Simple circuit, find equivalent resistance seen by the source

  1. Oct 3, 2012 #1
    1. The problem statement, all variables and given/known data
    For the circuit shown in Figure, find the
    equivalent resistance seen by the source. How much
    power is delivered by the source?

    http://sphotos-b.xx.fbcdn.net/hphotos-snc7/304377_496325960386924_988412599_n.jpg [Broken]

    2. Relevant equations
    Req = R1R2 / R1+ R2

    P = V^2 / R

    Thanks you for your time.
    3. The attempt at a solution
    I am not understanding what they meant by "seem by the source"
    so I assume that they want to find R equivalent for the whole thing.

    Start from the right to left
    2Ω + 1Ω = Req1 = 3Ω
    Req1 || 3Ω = Req2 = 1.5Ω
    4Ω + 1.5Ω+5Ω || 6Ω = Req3 = 3.82Ω
    ---->ReqS = 3.82Ω + 7Ω = 10.82Ω
    ---->Ps = Vs2/ ReqS = 18.11 W
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Oct 3, 2012 #2


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    Gold Member


    Yes that is correct.

    Imagine you were physically standing on the symbol for the 14V source voltage. What equivalent resistance do you "see" if looking to the right.

    Your answers for the resistance and power are correct.
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