A portable cooling thermoelectric box is designed to transport biological specimens at remote research stations. Under typical operating conditions, the temperature of the cold side of the thermoelectric element is maintained at 2 ∘C2\ ^\circ\text{C}2 ∘C while the temperature of the hot side is at 42 ∘C42\ ^\circ\text{C}42 ∘C.
Manufacturer data for this element show that at these temperatures:
It is claimed that the coefficient of performance (COP) of a thermoelectric refrigerator is much less than the COP of an ideal refrigerator.
Discuss whether this claim is valid for the thermoelectric refrigerator in this question.
Suggest why a low value of the COP is acceptable for this portable specimen cooler.
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.