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Thermodynamics FAQ

The efficiency of a heat engine is maximised by:

Operating between the widest possible temperature range. Carnot efficiency η = 1 − T_cold/T_hot; efficiency is maximised by maximising T_hot and minimising T_cold.

Short Answer

Operating between the widest possible temperature range is the best answer.

Thermodynamics questions usually test sign conventions, state variables, or what is being held constant. Before calculating, decide whether the system is exchanging heat, doing work, or both.

Carnot efficiency η = 1 − T_cold/T_hot; efficiency is maximised by maximising T_hot and minimising T_cold.

Why This Answer Is Correct

This is a Easy-level question in Thermodynamics. The prompt is really testing whether you can connect the concept to its defining physical relationship instead of picking a nearby-but-wrong term.

Write the system boundary first. Many thermodynamics mistakes disappear once you know what counts as heat, work, and internal-energy change.

Choices At A Glance

  • A. Maximising friction
  • B. Operating between the widest possible temperature range
  • C. Using more fuel
  • D. Increasing pressure only

When similar options appear on an exam, eliminate the ones that break the core law, use the wrong units, or confuse a definition with a consequence.

Topic Snapshot

Topic: Thermodynamics

Difficulty: Easy

Best next move: Re-state the governing law in your own words, then solve one more example from the same topic before moving on.