The piezometric head in a fluid flow system represents the sum of which two energy components?
- AKinetic head and Datum head.
- BPressure head and Datum head.Correct
- CPressure head and Kinetic head.
- DTotal energy head and Friction loss.
Solution
Concept
Components of piezometric head and hydraulic grade line
Formula
hpiezo = p / (ρ × g) + z
Step-by-step solution
1. Total energy head in Bernoulli's equation consists of pressure head, velocity head, and datum head. 2. Piezometric head represents the sum of the static pressure head (p / (ρ × g)) and elevation head (z). 3. It indicates the total potential energy per unit weight of fluid and defines the Hydraulic Grade Line (HGL). 4. Therefore, piezometric head comprises pressure head and datum head. Answer: B
Explanation
The piezometric head in fluid mechanics represents the sum of the static pressure head (p / γ) and the elevation or datum head (z). It indicates the height to which a liquid column rises in an open piezometer tube and defines the elevation of the Hydraulic Grade Line (HGL) relative to a datum.
Why the other options are wrong
A) Kinetic head and datum head do not correspond to any standard hydraulic head combination. C) Pressure head plus kinetic head represents dynamic/stagnation head, not piezometric head. D) Total energy head minus friction loss yields available head, not piezometric head.
Shortcut
Piezometric head = Pressure Head (p/γ) + Datum Head (z) = Hydraulic Grade Line (HGL).
Common mistake
Confusing piezometric head with stagnation head (pressure head + kinetic head).
Correct answer: B) Pressure head and Datum head.