🔍 Key Concepts

• Volumetric efficiency of a reciprocating air compressor • How leaks, restrictions, and wear each affect delivered air volume over time • Difference between a sudden failure and a gradual loss of capacity

💭 Think About

• For each listed fault, think: would this reduce the amount of air actually delivered per stroke, and would it happen gradually or instantly? • Consider which items would cause leakage, which would cause intake restriction, and which would cause internal clearance or blow‑by. • Ask yourself whether more than one of these conditions could be present at the same time and whether the question is focusing on a single cause or any cause that fits the symptom.

✅ Before You Answer

• For each option, decide: does this fault lower the mass of air taken in or discharged on every stroke over time? • Check which faults are likely to develop slowly with usage (wear, fouling) rather than causing an immediate, total failure. • Verify whether any option listed would not realistically lead to a gradual drop in compressor capacity, and eliminate it if so.