Air motors vs. compressors: A reciprocating air motor runs on the thermodynamic cycle that is the reverse of a reciprocating air compressor, not the same process sequence.

Introduction / Context:Reciprocating air motors and compressors are thermodynamic counterparts. Where a compressor consumes work to raise air pressure, an air motor expands compressed air to produce work.

Given Data / Assumptions:

• Idealized cycles to illustrate the relationship.
• Neglect small losses and throttling for the conceptual comparison.

Concept / Approach:On a p–v diagram, a compressor traces a loop representing intake at low pressure, compression, and discharge at high pressure. An air motor traces a reversed loop: admission at high pressure, expansion delivering work, and exhaust at low pressure. Hence the operation is not “similar” in process direction; it is the reverse.

Step-by-Step Solution:

Verification / Alternative check:Indicator diagrams from lab rigs show the compressor and air motor loops mirrored about an axis, confirming the reversal.

Why Other Options Are Wrong:Any “True/only if” variants misrepresent the fundamental reversal; specific heat transfer modes do not change that.

Common Pitfalls:Equating mechanical construction similarity (cylinders, pistons, valves) with thermodynamic process similarity; the hardware may look alike, but the cycle direction differs.

Final Answer:False