A venturi meter measures quantity of fluid by

A venturi meter measures quantity of fluid by

• A. difference in pressure between a constricted and full-size portion
• B. electronic measurement
• C. velocity of the fluid past a given point
• D. weight of the fluid

Answer: (A)

A venturi meter determines flow rate from the pressure difference that develops as fluid speeds up through a constricted throat. As the fluid enters the narrow section, it must accelerate to conserve mass, so its velocity increases and its pressure drops (Bernoulli’s principle). The pressure is higher in the wider section than at the throat, and the measured pressure difference between these two points is directly related to the velocity in the throat. By applying the continuity equation (A1 v1 = A2 v2) and Bernoulli, you can solve for the throat velocity and then multiply by the throat area to obtain the volumetric flow rate. In short, the meter measures how much pressure drops between the full-size portion and the constricted portion to infer the flow rate. It does not directly measure velocity at a point, nor weight of the fluid, nor rely on an electronic measurement alone.

A venturi meter determines flow rate from the pressure difference that develops as fluid speeds up through a constricted throat. As the fluid enters the narrow section, it must accelerate to conserve mass, so its velocity increases and its pressure drops (Bernoulli’s principle). The pressure is higher in the wider section than at the throat, and the measured pressure difference between these two points is directly related to the velocity in the throat. By applying the continuity equation (A1 v1 = A2 v2) and Bernoulli, you can solve for the throat velocity and then multiply by the throat area to obtain the volumetric flow rate. In short, the meter measures how much pressure drops between the full-size portion and the constricted portion to infer the flow rate. It does not directly measure velocity at a point, nor weight of the fluid, nor rely on an electronic measurement alone.