7. By steadily circulating a refrigerant at low temperature through passages in the walls of the freezer compartment, a refrigerator maintains the freezer temperature at -4°C when the air surrounding the refrigerator is at 25°C. The rate of heat transfer from the freezer compartment to the refrigerant is 8750 kJ/h and the power

input required to operate the refrigerator is 3500 kJ/h. Determine the coefficient of performance of the refrigerator and compare with the coefficient of performance of a reversible refrigeration cycle operating between reservoirs at the same temperatures. [MO1, MO4, MO5, MO6]