Work, Power and Energy
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Question : 15
Total: 30
A pump on the ground floor of a building can pump up water to fill a tank of volume 30 m3 in 15 min. If the tank is 40 m above the ground, and the efficiency of the pump is 30%, how much electric power is consumed by the pump.
Solution:
As given that
Volume of water= 30 m 3
Time taken by pump to fill tank= 15 min = 15 × 60 = 900 s
The height of tank = 40 m
The efficiency of pump = 30%
Consumption of power by pump = ?
Mass of water pumped = Volume × density= 30 × 10 3 = 10 3 k g ∕ m 3
Output power,P 0 =
=
=
= 13070
P i η =
P i =
=
= 43567 watt
Volume of water
Time taken by pump to fill tank
The height of tank = 40 m
The efficiency of pump = 30%
Consumption of power by pump = ?
Mass of water pumped = Volume × density
Output power,
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