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Homework Help: Calculate the equivalent resistance

  1. Feb 1, 2015 #1
    1. The problem statement, all variables and given/known data
    Ignore the internal resistance of the battery and assume it is merely a battery. Calculate the equivalent resistance of the circuit.

    2. Relevant equations
    1/Req = 1/R + 1/R ... (parallel)
    Req = R + R .... (series)

    3. The attempt at a solution
    I know this is fairly simple but I dont understand how you would calculate the equivalent resistance for the three resistors (3.2 ohms, 7.1 ohms, 5.8 ohms). I assumed they were in series and simply added them, and then added 1.0 ohms and 4.5 ohms to get the total resistance. I think this is wrong, can someone explain how you would go about calculating the Req?
  2. jcsd
  3. Feb 1, 2015 #2
    I'm afraid you're wrong. All of them aren't in series. See the figure I've uploaded. What can you infer from that? Always deal with 2 resistances at a time. Don't involve 3 together.

    Attached Files:

  4. Feb 1, 2015 #3
    I see what you are saying, since 7.1 and 5.8 are in series, they must be added together? And then added in parallel to 3.2?
  5. Feb 1, 2015 #4
    You got that right mate!
  6. Feb 1, 2015 #5
  7. Feb 1, 2015 #6
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