Question

If the flow rate of a 5 hp water pump is 250 l/min with a total head of 25 m, then the energy/electricity consumption of the pump will be

• A. 3.73 kWh
• B. 5 kWh
• C. 3.73 Wh
• D. 5 Wh

Hint:

1 hp = 746 W = 0.746 kW.
Energy (kWh) = Power (kW) × Time (hours).
Pump efficiency affects actual power consumption.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This question tests the calculation of energy consumption of a pump.

Step 2: Key Formula or Approach:
Hydraulic power = \(\rho \times g \times Q \times H\)
Pump power (electrical) = Hydraulic power Pump efficiency
Energy consumption = Power \(\times\) Time

Step 3: Detailed Explanation:
Given:
Pump power rating = 5 hp
1 hp = 746 W
So, input power = \(5 \times 746 = 3730 \text{ W} = 3.73 \text{ kW}\)
For 1 hour of operation, energy consumption = \(3.73 \text{ kW} \times 1 \text{ hour} = 3.73 \text{ kWh}\)
The flow rate and head are not needed since the pump rating is already given.
Thus, the energy consumption is 3.73 kWh.

Step 4: Final Answer:
Thus, the energy/electricity consumption is 3.73 kWh.
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