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Carnot Refrigerator coefficient of performance

  1. Nov 28, 2006 #1
    A Carnot refrigerator operating between -10.0 C and 40.0 C extracts heat from the cold reservoir at the rate 300 J/s. What are (a) the coefficient of performance of this refrigerator, (b) the rate at which work is done on the refrigerator and (c) the rate at which heat is exhausted to the hot side?

    A. All right for i got the answer to be 5.26 because
    T_c/(T_h-T_c)=coefficient of performance
    This is correct

    For Part B and C
    I am unsure how to approach this
    please someone help me with an equation....
  2. jcsd
  3. Nov 29, 2006 #2

    Andrew Mason

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    The co-efficient of performance of a refrigerator is the ratio of heat removed from the cold reservoir to the work done:

    [tex]\text{COP} =\frac{Q_c}{W} = \frac{Q_c}{Q_h-Q_c} = \frac{Q_c/Q_h} {1 - Q_c/Q_h} [/tex]

    So W = Qc/COP. Since it is a Carnot cycle: Qc/Qh = Tc/Th

    To find Qh use W = Qh-Qc

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