Consider the following statements to reply further: 1. Pumps in series operation allow the head to increase. 2. Pumps in series operation increase the flow rate. 3. Pumps in parallel operation increase the flow rate. 4. Pumps in parallel operation allow the head to increase. Which of these statements are incorrect?
- A1 and 3
- B1 and 4
- C2 and 4Correct
- D3 and 4
Solution
Concept
Pump combinations
Step-by-step solution
1. Series: heads add (1 true); discharge is the same (2 false). 2. Parallel: discharges add (3 true); head is the same (4 false). 3. Incorrect statements: 2 and 4.
Explanation
In series the head increases; in parallel the flow rate increases.
Why the other options are wrong
Statements 1 and 3 are correct, so options with them are wrong.
Shortcut
Series: head adds. Parallel: flow adds.
Correct answer: C) 2 and 4