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Circuit with only resistors and multiple batteries

  1. Mar 31, 2009 #1
    in a simple circuit with only resistors and multiple batteries and multiple loops, which side is the positive and negative on the resistors? I am referring to the case of Kirchhoff rule in which I have to come up with equations to solve for current or voltage. But I got confused on voltage drop and gain thing.
  2. jcsd
  3. Mar 31, 2009 #2
    Re: Resistors.

    Do you mean "what side is positive and negative" in the real circuit, or what side should you choose + and - when solving the circuit?

    If the former - you can't tell until you solve the circuit!

    If the later - I always choose a direction for the current in each branch, voltage drops in the direction of the current. I thought of the choice of direction as a guess; if a current turns up negative, it means I guessed wrong.

    Does this help?
  4. Mar 31, 2009 #3
    Re: Resistors.

    yes, thanks alot.
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