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Homework Help: Another circuit task, but tricky.

  1. Dec 22, 2011 #1
    1. The problem statement, all variables and given/known data
    A voltaic element with electromotive voltage E=1,1V and with internal resistance r=1ohm, is connected to an external resistor with the resistance R=9ohm. Determine the current I which circulates in the circuit, also the falls of voltage on the external portion of the circuit VR and on the internal portion of the circuit Vr. Also, at what yield the voltaic element works?

    2. Relevant equations


    3. The attempt at a solution

    The first step is easy, I mean calculating the I (I=E/(r+R)=1,1/(1+10)=0,11), but then I have some doubts.. Will it be right to calculate VR as VR=I*R and Vr as Vr=I*r? or maybe I must reduce something because it says: "the falls of voltage" so there should be a higher value and a smaller one.
  2. jcsd
  3. Dec 22, 2011 #2


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    Staff: Mentor

    It looks like you are doing it correctly. You calculated the current correctly, so now you get each individual voltage drop across each resistor by multiplying the current by each individual resistance. You can check your answers, because the sum of the voltage drops across the resistors must equal the value of the voltage source, correct?
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