How does the head vary according to the pump affinity laws?

The pump affinity laws describe how changes in the speed of a pump affect its performance characteristics, specifically flow rate, head, and power consumption. According to these laws, the head developed by a centrifugal pump varies with the square of the speed. This means that if the speed of the pump is doubled, the hydraulic head produced by the pump increases by a factor of four (2 squared).

This relationship is critical for understanding pump performance in different operational scenarios, allowing engineers to predict how changes in speed can impact the system designed for effective fluid movement. It highlights the nonlinear response of head to speed changes, emphasizing the importance of precise speed adjustment in pump applications to achieve desired operational outcomes without oversizing or overburdening the pump.

The other choices illustrate different relationships that are not consistent with the affinity laws. While speed indeed affects flow rate and power, the specific relationship of head dependence on speed is uniquely quadratic, making this understanding essential for effective plumbing system design and operation.