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))`

Explanation

Here, volume of water `=30m^(3),t=15min. =15xx60=900s.`
Height, `h=40m, ` efficiency, `eta=30%.`
As density of water `=rho=10^(3)kg//m^(3),:.` Mass of water pumped , `m=` volume `xx` density`=30xx10^(3)kg`
Actual power consumed or output power `P_(0)=(W)/(t)=(mgh)/(t)=(30xx10^(3)xx9.8xx40)/(900)=13070wat t`
If `p_(i)` is input poewr (required ), then as `eta=(P_(0))/(P_(i)):. (P_(0))/(eta)=(13070)/(30//100)=43567W=43.567kW`