b) A frozen food compartment is kept at \( -12^{\circ} \mathrm{C} \) by a refrigerator in a kitchen with ambient temperature of \( 30^{\circ} \mathrm{C} \). The heat released by the food in the compartment is estimated to be \( 3500 \mathrm{~kJ} / \mathrm{h} \) and the heat rejection to the surrounding is \( 4500 \mathrm{~kJ} / \mathrm{h} \). i) Sketch the schematic diagram of the refrigerator and label clearly the properties given. ii) Determine the power input to the compressor, \( \boldsymbol{k W} \). iii) Calculate the coefficient of performance of the refrigerator. iv) If the refrigerator operates as reversible Carnot cycle, determine the power input to the compressor for the same refrigerating effect, \( k W \).