Question

Capacity of a water tank built at the height of 10 m is 2000 litres . A lift pump of 2kW is used to fill this tank . If the efficiency of the tank is 70 % , calculate the time required to fill the tank .

Answer 1

Answer:

Let's see what's given in the question,

Power of pump= 2KW = 2000 watts

Height= 10 metre

Time=1 minute= 60 seconds

As we know

Power- Work done/ Time

And Work done= mgh

So,

Power= mgh/ Time

Keeping the value, in Sl units

2000 watt = (mx 9.81×10 )/ 60

m= mass of water = 1223.2415 kgs

If you wish to convert it in litres then,

Density= Mass / Volume

Or, Volume= Mass/ Density

Volume=1223.2415/ 1000

Volume = 1.2232415 meter cube

And if you want in litres, then

1 meter cube = 1000 litres

So, Volume=1.2232415 × 1000 litres

= 1223.2415 litres

So your pump is giving out large amount of water in 1 minute, 1223.24 litres, don't waste it.

Answer 2

Answer:

Thus, the efficiency of the pump should be 27.78%.