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InterviewSolution
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A pump on the ground floor of a building can pump of water to fill a tank of volume `30 ms^(3)` in `15 min`. If the tank is `40m` above the ground and the efficiency of the pump is `30 %` , how much electric power is consumed by the pump? `("Take" g = 10 ms^(2))` |
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Answer» Here, volume of water = `30ms^(3)`, t=15min = `15 xx 60=90s` h=40m, n=`30%` As the density of water = p = `10^(3) kg m^(-3)` Mass of water pumped, m = volume xx density = `30 xx 10^(3)` kg Actual power consumed or output `p_(0) = W//t = mgh//t` `rArr p_(0)(30 xx 10^(3) xx 9.8 xx 40)//900 = 13070 watt` If pi is input power (required), then as `eta = p_(0)//p_(i)rArr p_(i)=p_(0)//eta` = `13070(30//100) = 43567 W = 43.56` KW |
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