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Homework Help: Efficiency of electrical power plant

  1. Aug 4, 2009 #1
    1. The problem statement, all variables and given/known data

    An electrical power plant manages to transfer 88 percent of the heat produced in the burning of fossil fuel to convert water to steam. Of the heat carried by the steam, 40 percent is converted to the mechanical energy of the spinning turbine. Which best describes the overall efficiency of the heat-to-work conversion in the plant?

    --> greater than 88 percent
    --> 88 percent
    --> 40 percent
    --> less than 40 percent

    2. Relevant equations

    eff = 1 - (Qc/Qh)

    3. The attempt at a solution

    Uhh..? No idea lol, I tried using this equation but I got like .54 (when i plugged in .40 for Qc and .88 for Qh)
  2. jcsd
  3. Aug 4, 2009 #2


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    Science Advisor
    Homework Helper

    Re: Efficiency

    Efficiencies multiply, if you have a source that is 50% that drives another stage that is 50% then overall you have 25%
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