Cavitation is the formation of bubbles in a liquid typically caused by the movement of a propeller.

• A. Acceptance Test
• B. Authority Having Jurisdiction
• C. Cavitation
• D. Certification Test

Answer: (C)

Cavitation is the rapid formation of vapor-filled bubbles in a liquid when the local pressure falls below the liquid’s vapor pressure. In propellers, the moving blades create regions of very low pressure on the suction side; if this pressure drops below the liquid’s vapor pressure, bubbles form. As those bubbles move into higher-pressure areas, they collapse violently, which can cause pitting, vibration, and noise. That describes the phenomenon tied to moving propellers, making it the correct concept in the question. The other terms refer to testing or regulatory processes, not to a fluid-dynamic phenomenon, so they don’t describe what cavitation is.