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Homework Help: Thermodynamics Problem Solved!

  1. Jun 11, 2007 #1
    1. The problem statement, all variables and given/known data

    Show that no refrigerator operating between two reservoirs at a given temperature can have higher co-efficient of performance than a Carnot refrigerator operating between the same two reservoirs.

    2. Relevant equations
    3. The attempt at a solution

    Please check if I am correct

    A perfect refrigerator is one in which no work is required to take heat from the low temperature region to the high temp. region.
    This is not possible according to the second law of Thermodynamics
    The coefficient of performance of a refrigerator
    COP = QL / W
    where W = work done
    from the first law of thermodynamics we can write
    COPideal = QL / ( QH - QL )
    = TL / ( TH - TL )
    = ( TL / TH) / [ 1 - ( TL / TH) ]
    = ( TL / TH) / eideal
    = analagous to an ideal Carnot refrigerator
    Last edited: Jun 11, 2007
  2. jcsd
  3. Jun 11, 2007 #2


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    Homework Helper
    Gold Member

    I'd prove this by contradiction.
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