Dissipation of watts

Discussion in 'Math' started by tjjam2003, Apr 8, 2006.

  1. tjjam2003

    Thread Starter Member

    Apr 5, 2006
    22
    0
    What voltage is required to cause a dissipation of 10 watts in a resistor when the current through the resistor is 150mA?? The book says 66.67 volts.
    Can you please help the newbie out???
     
  2. rodn.m

    Member

    May 3, 2006
    12
    0
    P=E*I
    where E=66.67 volts
    I=150 mA
    150/1000=.15*66.67=10watts
     
  3. radiosmoke

    Member

    May 30, 2006
    17
    0
    -------------
    The book is asking for you to find out what the voltage is.
    That's why they didn't give you the voltage to start with.

    you need to use the formula below to find out what the voltage should be, when only the power and current are known. If you use voltage to prove your answer, you are going at it backwards from what the book is getting at and that isn't the way to use the formula.
    so use
    V = W ÷ A

    10w/150mA = 66.6volts

    Hope this helps
     
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