Question

A pump's power is frequently provided as pressure head, the maximum vertical height a column of water is displaced. If water is replaced with mercury, a fluid with a higher density, the pressure head will:

A. increase
B. decrease
C. stay the same
D. impossible to tell from the information provided

Answer 1

If water in a pressure head system is replaced with denser mercury, the pressure head will decrease due to the higher density of mercury requiring less height to exert the same pressure.

Step-by-step explanation:

When a pump's power is provided as pressure head for displacing water, and if water is replaced with mercury, which is a fluid with a higher density, the pressure head will decrease. This is because the pressure head depends on the fluid's density as well as the gravitational force and the height of the column. Since mercury is denser than water, a smaller height of mercury is needed to exert the same pressure as a taller column of water.