Question

What is the term for the pressure that creates water flow between two points. 1) Constant of proportionality 2) flow rate pressure 3) hydraulic head or 4) net positive suction head

Answer 1

The answer to this question is option 3)Hydraulic head.

Hydraulic head is the total energy of the fluid that is flowing,

H P +2+ pg 29

It has three different terms of which the change may be in any of them or in all of the three terms that can cause the liquid to flow between two points.

1. Pressure head

2. Elevation

3. Kinetic Energy

Pressure head :

Difference in pressure at two different points in the fluid system can cause the fluid to flow from high pressure to low pressure even if there is no difference in elevation of the two points and also velocity.

Elevation :

Elevation is also responsible for the flow of liquid as it is nothing but the difference in gravitational potential energy i.e, the liquid flows from higher elevations to lower elevations.

Kinetic Energy :

As obvious as it is, if there is velocity gradient along the fluid, means there is convective acceleration. Any convection arises only when there is flow. Velocity itself means that the liquid is flowing.

The difference in hydraulic head is represented by hydraulic gradient which is responsible for flow.

Option 2 cannot be the answer since there is no such term as "Flow rate pressure"

Option 4) Net positive suction head arises in the case of pumps which is the difference between suction pressure and the vapor pressure. Hence it cannot be the answer either.