Venturi meters operate based on what principle?

Venturi meters operate based on the principle of pressure differential. They measure the flow rate of fluids by creating a constriction in the flow path, which accelerates the fluid and results in a drop in pressure at the narrowest point of the meter. According to Bernoulli's principle, as the fluid velocity increases, the pressure decreases.

This pressure drop between the wider sections of the meter and the throat (the narrowest part) allows for the calculation of flow rate. By using the principle of pressure differential, venturi meters can provide accurate flow measurements necessary for various applications in water treatment and distribution systems.

Other principles listed, such as constant flow, kinetic energy, and temperature difference, do not accurately describe the operational mechanism of a venturi meter. These other options do not encompass the fundamental physics that define how the venturi effect allows for the measurement of fluid flow.