Question

Given below are two statements :
Statement (I) : When two pumps are installed in series, discharge remaining the same, water is lifted to greater height compared to a single pump.
Statement (II) : When two pumps are installed in parallel then not only the discharge increases but water is also lifted to greater height compared to a single pump.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

Remember:
- Series = Increases Head (lifts higher)
- Parallel = Increases Discharge (flows more)

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
To achieve different hydraulic requirements, multiple pumps can be installed in either series or parallel configurations.
Detailed Explanation:
Let us analyze both configurations:
- Series Configuration [Statement (I)]: In a series connection, the discharge from the first pump is piped directly into the suction inlet of the second pump. The total discharge ($Q$) remains constant, but the head ($H$) of each pump adds up: \[ H_{\text{total}} = H_1 + H_2 \] This allows water to be lifted to a much greater height. Thus, Statement (I) is true.
- Parallel Configuration [Statement (II)]: In a parallel connection, multiple pumps draw from a common suction line and discharge into a common manifold. The total discharge adds up: \[ Q_{\text{total}} = Q_1 + Q_2 \] However, the operating head remains equal to that of a single pump ($H_{\text{total}} = H_1 = H_2$). It does not lift water to a greater height. Thus, Statement (II) is false.

Step 2: Final Answer:
Since Statement (I) is true and Statement (II) is false, the correct choice is Option (C).