\textbf{197-} A Carnot refrigerator operates between temperatures $27^\circ\text{C}$ and $127^\circ\text{C}$ and does $127\,\text{J}$ of work. What is its coefficient of performance?
(1) $\dfrac{4}{3}$ \hfill (2) $\dfrac{5}{3}$ \hfill (3) $3$ \hfill (4) $4$
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