Final answer:
The type of pump being described is a centrifugal pump, which uses an impeller and diffuser in combination with a Venturi throat to increase water velocity and pressure.
Option A, Centrifugal pump, is correct
Step-by-step explanation:
The type of pump that uses an impeller-diffuser to push water using a Venturi throat to get velocity is a centrifugal pump. A centrifugal pump works on the principle of converting rotational kinetic energy, typically from an electric motor or an engine, to energy in a moving fluid. A portion of the energy goes into increasing the fluid’s kinetic energy (velocity), and as the fluid exits through the diffuser, its velocity is reduced, which increases pressure, allowing the fluid to be pushed through a pipe system. This contrasts with positive displacement pumps, which work by trapping a fixed amount of fluid and forcing it through the discharge, creating a more steady flow.
The Venturi throat in a centrifugal pump is a narrow passage where the velocity of the fluid increases, causing a decrease in pressure based on Bernoulli's principle. This combination of impeller, diffuser, and Venturi throat allows centrifugal pumps to efficiently move large volumes of fluid at relatively low pressures.
In summary, option (a) centrifugal pump is the correct answer for the type of pump described.