Thermodynamics Part 3

Given, power consumed by refrigerator $P=35\ \mathrm{W}=35\ \mathrm{Js}^{-1}$ ∴ Energy consumed by refrigerator per second, $W=35\ \mathrm{J}$ Lower temperature limit, $T_{L}=-10^{\circ}\mathrm{C}=263\ \mathrm{K}$ Higher temperature limit, $T_{H}=25^{\circ}\mathrm{C}=298\ \mathrm{K}$ The coefficient of performance of refrigerator is given as $COP=\frac{T_{L}}{T_{H}-T_{L}}=\frac{Q}{W}$ Here, Q is the heat transferred by the refrigerator. Substituting the values, we get $\frac{263}{298-263}=\frac{Q}{35}$ $\Rightarrow Q=\frac{263}{35}\times35=263\ \mathrm{J}/\mathrm{s}$ Thus, the average heat transfer by refrigerator per second is $263\ \mathrm{Js}^{-1}$.