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Willan's line (steam engine): straight-line relation Willan's line for a steam engine is an approximately straight-line plot between steam consumption per hour and which output measure? Choose the correct option.

Difficulty: Medium

Indicated power
Brake power
Efficiency
Steam pressure

Correct Answer: Indicated power

Explanation:

Concept
For steam engines, Willan's line plots steam consumption rate vs. indicated power; its intercept estimates the no-load steam consumption (friction/standby losses) and the slope gives steam rate per kW indicated. (For IC engines, an analogous Willan's line is often shown for fuel vs. brake power.)

Final Answer
Indicated power

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