Vidyalelo
Mechanical Engineering · Q474

Hydraulics And Fluid Mechanics

Engineering and GATE · Mechanical Engineering · question 474

Q474

The pressure of the liquid flowing through the divergent portion of a Venturimeter

A.
Remains constant
B.
Increases
Answer
C.
Decreases
D.
Depends upon mass of liquid

Answer: Option B

Solution

Answer: Option B
Solution:
The Venturimeter works on Bernoulli’s principle, which relates pressure, velocity, and elevation in a flowing fluid.

When fluid enters the converging section, the cross-sectional area decreases, causing velocity to increase and pressure to drop until it reaches the throat — the narrowest point.

In the divergent (diffuser) section after the throat, the cross-sectional area increases. This causes the velocity of the fluid to decrease due to continuity of flow.

According to Bernoulli’s principle, when velocity decreases, the static pressure increases — this is known as pressure recovery.

The increase in pressure is not dependent on the mass of the liquid but on the conversion of kinetic energy back into pressure energy as the fluid decelerates.

Therefore, in the divergent portion of a Venturimeter, the pressure increases.