A positive displacement pump is characterized by what operation?

A positive displacement pump is characterized by its ability to discharge an equal amount of fluid with each cycle of operation. This pumping mechanism works by trapping a fixed volume of fluid and then forcing it into the discharge pipe, resulting in a consistent and predictable flow rate. This characteristic makes positive displacement pumps ideal for applications where accurate and steady flow is crucial, regardless of the discharge pressure.

In contrast to other types of pumps, positive displacement pumps do not adjust the amount of fluid based on operating conditions such as pressure or speed; rather, they maintain consistent output regardless of the system's resistance. This reliability in delivering the same volume each cycle is why option B accurately describes the operation of a positive displacement pump.