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Homework Help: Help With Circuits

  1. Feb 13, 2010 #1
    1. The problem statement, all variables and given/known data

    http://img130.imageshack.us/img130/2366/capturewvb.jpg" [Broken]

    2. Relevant equations


    3. The attempt at a solution
    Given Information
    V I R
    R1 12 V 2 ohm
    R2 4 ohm
    R3 24 V 4 ohm
    R4 8 ohm

    I can calculate the current of R1
    V = IR
    I = V/R
    I = 12 V/2 = 6 A = I1

    pl if i'm correct sense R1 and R2 are in parrallel and right next to the battery they should share the same voltage?

    R2 = 12 V
    from which I can calculate the current
    V = IR
    I = V/R = 12 V / 4 ohm = 3 A = I2

    now the current for the whole batter should just be I1 + I2? = 6 A + 3 A = 9 A = I battery

    I can fidn the R battery by doing

    (1/R1 + 1/R2)^-1 + (1/R3 + 1/R4)^-1 = (1/2 + 1/4)^-1 + (1/4 + 1/8)^-1 = 4 ohm = R battery

    am i doing this right were do i go from here?
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 13, 2010 #2
    Find the equivalent resistance of both of the two resistors in parallel then you'll have a circuit with two resistors in series and you should be able to find what you need to find.

    The voltage drop across resistors in parallel will be equal but the current will not.
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