Analyzing Heat Engine Efficiency

00:00 5 marks

A heat engine operates in a cyclic process. In one complete cycle, it absorbs heat \(Q_h\) from a high-temperature reservoir and expels heat \(Q_c\) to a low-temperature reservoir.

The engine absorbs \(Q_h = 1500 \text{ J}\) and expels \(Q_c = 600 \text{ J}\) in each cycle.

Part a

4 minutes 3 marks

Question

Calculate the net work output \(W\) per cycle of the heat engine.

Hint Hint

Hint

Apply the first law of thermodynamics to the engine cycle. The net work done by the engine equals the net heat transfer.

Answer Answer
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Complete Answer

900 J

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Part b

4 minutes 2 marks

Question

Calculate the thermal efficiency \(\eta\) of the engine.

Hint Hint

Hint

Efficiency relates the useful work output to the heat energy input from the hot reservoir. Alternatively, it can be calculated directly from the heat transfers.

Answer Answer
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Complete Answer

0.60

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