A cryogenic cooling system operates as an ideal reversed heat engine to maintain a biological specimen storage chamber at a constant temperature of −73 ∘C-73\ ^\circ\text{C}−73 ∘C. The system rejects thermal energy to a liquid-cooled condenser at a temperature of 27 ∘C27\ ^\circ\text{C}27 ∘C.
During continuous operation, the rate of heat transfer to the condenser is 1.35 kW1.35\text{ kW}1.35 kW.
Calculate the minimum electrical input power required to operate this cooling system.
29 exam-style questions on AQA A Level Physics Thermodynamics and engines (A-level only), covering First law of thermodynamics (A-level only), Non-flow processes (A-level only), The $p$ - $V$ diagram (A-level only), Engine cycles (A-level only), Second Law and engines (A-level only), and Reversed heat engines (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.