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How many joules of energy are supplied.

  1. Sep 28, 2011 #1
    1. The problem statement, all variables and given/known data
    How many coulombs of electricity pass through a lamp when a current of 5A flows for 3 minutes. Answer: 900C
    In this time 27,000 joules of electrical energy is converted into heat and light. How many joules of energy are supplied by each coulomb.

    2. Relevant equations

    3. The attempt at a solution
    27000/900 = 30V
    P=30 x 5 = 150W
    E= 150 x 180 = 2700

    Have I done this correctly?
  2. jcsd
  3. Sep 28, 2011 #2
    Your first part is correct, not sure what you're trying to do with all those other equations listed though to calculate how much energy is supplied by each coulomb. It's a lot easier than what you're trying to do.
  4. Sep 28, 2011 #3


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    Staff: Mentor

    one volt is one Joule/coulomb
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