The vertical distance between the centre line of a pump and the point of delivery is known as
- Asuction head
- Bdelivery headCorrect
- Cdynamic head
- Dtotal head
Solution
Concept
Delivery head is the vertical height from the pump centre line to the point where the liquid is delivered.
Formula
Hs = hs + hd
Step-by-step solution
1. The suction head (hs) is the vertical height from the sump water level to the pump centre line. 2. The delivery head (hd) is the vertical height from the pump centre line to the point of delivery. 3. So the distance asked in the question is the delivery head.
Explanation
The pump centre line divides the total lift into two parts. The part below the centre line is the suction head. The part above it, up to the outlet, is the delivery head.
Why the other options are wrong
A: Suction head is measured below the pump centre line, down to the sump level. C: Dynamic head also includes friction losses and velocity head, so it is not only a vertical distance. D: Total head is suction head plus delivery head, plus losses.
Shortcut
Above the pump = delivery. Below the pump = suction.
Common mistake
Students mix up delivery head with total (static) head, which is suction head plus delivery head.
Correct answer: B) delivery head