The discharge pressure of a centrifugal pump is influenced by the speed of the impeller.

• A. True
• B. False
• C. Not enough information
• D. Only at high temperature

Answer: (A)

Increasing the impeller speed adds more energy to the fluid, which raises the head the pump can develop. For a centrifugal pump with fixed geometry, the head is proportional to the square of the speed (H ∝ N^2). Since discharge pressure is tied to the head by P_discharge ≈ ρ g H, spinning the impeller faster increases the discharge pressure. The actual pressure at the discharge also depends on the system’s resistance, so the operating point may shift, but the capability to generate higher pressure grows with speed. Temperature isn’t the controlling factor here, and there’s enough information to connect speed to pressure via the head relation.