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Homework Help: Need help with Parallel circuits

  1. Sep 5, 2010 #1


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    1. The problem statement, all variables and given/known data

    2. Relevant equations

    V=IR and What not

    3. The attempt at a solution

    I have attempted it many different ways
    I need your help, I have preliminary exams coming up, Please do me a favour.

    Regards, FCB
  2. jcsd
  3. Sep 5, 2010 #2


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    Homework Helper

    Show at least one attempt.
  4. Sep 5, 2010 #3


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    ok so we have 5 ohm and 20 ohm , in parallel, which are both in series with 50ohm

    now for equivalent resistance in parallel

    1 / R eq= 1/R1 + 1/R2

    ie R eq= R1 * R2 / ( R1+R2)

    therefore we have ( 4ohm in series with 50 ohm)

    then R eq= 54ohm ( add them when in series )

    then apply v=IR to get total current in circuit

    I= V/R
    = 12 / 54

    now when this current gets to the section where it splits in two, the current is divided and the majority of current goes throguh the least resistance

    current through 5ohm = 20 / ( 25) * 12 / 54
    current through 20ohm = 5 / ( 25) * 12/54
  5. Sep 5, 2010 #4


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    Homework Helper

    Your calculations are correct.
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