In pump priming, which statement best describes how water enters the pump?

• A. A Atmospheric pressure forces it into the pump
• B. B The pump pulls the water in from the static source
• C. C The rotating motion of the centrifugal pump creates a vacuum
• D. D Of increase in atmospheric pressure in the pump

Answer: (A)

When a pump is primed, the suction side is filled with water and the impeller begins turning, creating a lower pressure inside the pump. The water in the intake source is exposed to atmospheric pressure, and that atmospheric pressure pushes the water into the pump where the internal pressure is lower. That push from above the water surface is what drives water into the pump and starts the flow.

This is why the statement that atmospheric pressure forces water into the pump best describes priming. The pump isn’t pulling water up from a static source on its own; it relies on the atmospheric pressure acting on the water surface to push it into the lower-pressure region inside the pump. The idea of a vacuum is a part of the mechanism, but the primary driving force is the atmospheric pressure on the source water, not an increase of pressure inside the pump.