Question

An electric pump rated 1.5 KW lifts 200kg of water through a vertical height of 6m in 10 secs: way is the efficiency of the pump?​

Answer 1

80%

Step-by-step explanation:

Efficiency = Power output / Power input × 100 %

To calculate efficiency we need to find power output of electric pump.

We can use,

Work done = Energy change

Work done per second = Energy change per second

Work done per second = Power

Therefore, Power = Energy change per second

= Change in potential energy of water per second

=mgh / t

= 200× 10×6 / 10

= 1200 W = 1.2 kW

Now use the first equation to find efficiency,

Efficiency =
`(1.2)/(1.5)` × 100%

= 80 %