Q: An electric pump is used to fill an overhead tank of capacity 9 m3 kept at a height of 10 m above the ground. If the pump takes 5 minutes to fill the tank by consuming 10 kW power, efficiency of the pump should be
(take g = 10 ms–2)
(a) 60 %
(b) 40 %
(c) 20%
(d) 30 %
Ans: (d)