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Homework Help: C.O.P/Refrigerator (Finding Temp)

  1. Oct 6, 2011 #1
    1. The problem statement, all variables and given/known data

    A refrigerator is operating at a C.O.P of 0.98, which is 13% of the max C.O.P theoretically possible. The temperature of the freezer compartment of the refrigerator is -12 Celsius. What is the temperature of the surrounding room (in Celsius)?

    2. Relevant equations

    C.O.P = Qo/W

    3. The attempt at a solution

    Cannot interpret the question correctly
  2. jcsd
  3. Oct 6, 2011 #2

    Andrew Mason

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    Science Advisor
    Homework Helper

    What kind of thermodynamic cycle would be the most efficient (highest COP)? What is the expression for that highest COP in terms of temperature of the hot and cold reservoirs? What is Qo?

  4. Oct 6, 2011 #3
    Assume Qo is energy taken from freezer and Q1 is energy released after each cycle. For Carnot process

    T1/To equals Q1/Qo

    Also W equals Q1 - Qo

    In ideal case cop equals 0.98/.13, because we know in non ideal case cop is .98

    But cop equals Qo/(Q1-Qo) take reciprocal hence get Q1/Qo, from which use relationship with T1 and To to get T1. Remember that To is 261. My answer is around 295K

    Hope I haven't given too much away
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