Reduced capacity, accompanied by vibration and noise at the suction of a centrifugal pump, results from cavitation in the fluid being pumped. Cavitation describes the formation of __________.

Correct Answer: Option A — vapor pockets

Cavitation is the rapid formation and subsequent collapse of vapor pockets within the fluid stream. When these bubbles reach higher pressure zones, they implode, causing localized shock waves that result in noise, vibration, and severe pitting of the impeller material, significantly reducing the pump's hydraulic efficiency and structural integrity.