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Short electricity problem

  1. Feb 20, 2009 #1
    1. The problem statement, all variables and given/known data

    2) 2 resistors, 42 and 64 ohms, are connected in parallel. The current through the 64 resistor is 3A. Determine the current in the other esistor and what is the total power supplied by the two resistors?
    2. Relevant equations



    3. The attempt at a solution


    2) How could i possibly have enough info to do this one?
     
    Last edited: Feb 20, 2009
  2. jcsd
  3. Feb 20, 2009 #2

    mgb_phys

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    1, Whats the overall resistance of 2 resistors in paralel (extend this to 3 resistors)?
     
  4. Feb 20, 2009 #3
    The resistance is not the same if the pieces are connected in parallel.

    Resistors connected in parallel follow the law

    1/(R.total)=1/(R.1)+1/(R.2)+1/(R.3)...

    Where R.total is the total resistanse and R.1 is the resistanse of the first resistor, R.2 is the resistanse of the second resistor etc. etc.
     
  5. Feb 20, 2009 #4
    thanks figured that one out, can you help me with the second one?
     
  6. Feb 20, 2009 #5

    mgb_phys

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    Assume the same voltage across both resistors.
    Then V=IR for the known and I =V/R for the unknown.
    (it should also be obvious how to skip a step)
     
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