Two heat engines are arranged in series

PHYSICS · Subjective · A Level · Physics · Engineering physics · Engineering physics

Problem

Two heat engines are arranged in series. Engine A receives

8.0\times10^3\,\text{J}

of heat from a source at

600\,\text{K}

and has an efficiency of

25\,\%

. All of the heat it rejects is absorbed by Engine B, which finally rejects

3.0\times10^3\,\text{J}

of heat to a sink at

300\,\text{K}

. (a) Calculate the heat rejected by Engine A. (b) Determine the heat absorbed by Engine B. (c) Find the work output of each engine and the total work obtained from the pair. (d) Compute the overall efficiency of the combined system and state, with justification, whether this value is consistent with the Second Law for engines operating between

600\,\text{K}

and

300\,\text{K}

Related theory

Heat Engines
Second law and Carnot cycle
Thermodynamics
Carnot engine

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