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Two-stage reciprocating air compressors: find the incorrect statement (if any). Consider intercooling, minimum work allocation per stage, and the definition of volumetric efficiency. Determine which statement is wrong; if all are correct, select 'none of the above'.

Difficulty: Medium

In a two-stage reciprocating air compressor with complete intercooling, maximum work is saved.
The minimum work required for a two-stage compressor equals twice the work required for each stage.
The ratio of free air delivered per stroke to the piston’s swept volume is called volumetric efficiency.
none of the above

Correct Answer: none of the above

Explanation:

Given facts
Two-stage compression with perfect intercooling (and equal pressure ratios) minimizes total work. For minimum-work allocation, both stages do equal work, so total work = 2 × (work per stage). Volumetric efficiency is defined as (free air delivery per stroke)/(swept volume).

Evaluation
A is correct: perfect intercooling gives the least work.
B is correct: at the minimum-work condition, work is split equally; hence total is twice that per stage.
C is the standard definition of volumetric efficiency.

Conclusion
Since A, B, and C are correct, there is no wrong statement among them.

Two-stage reciprocating air compressors: find the incorrect statement (if any). Consider intercooling, minimum work allocation per stage, and the definition of volumetric efficiency. Determine which statement is wrong; if all are correct, select 'none of the above'.

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