Question

A 750W motor drives a pump which lifts 300 litres of water per minute to a height of 6m.
The efficiency of motor is nearly ? (Take acceleration due to gravity be 10 m/s^2)
A) 30 % B) 50% C) 40% D) 20%

Answer 1

The correct option is C) 40%.

Step-by-step explanation:

Consider the provided information.

A 750W motor drives a pump which lifts 300 litres of water per minute to a height of 6m.

The efficiency of motor is: $\eta=\frac{P_{out}}{P_{in}}\times 100\%$

Output power = mgh/t and $P_{in}=750$

Substitute the respective values in the above formula.

$\eta=\frac{mgh/t}{750}\times 100\%$

$\eta=\frac{\frac{300\times 10\times6}{60}}{750}\times 100\%$

$\eta=\frac{300}{750}\times 100\%$

$\eta=40\%$

Hence, the correct option is C) 40%.

https://brainly.in/question/1925954

An engine pumps up 100 kg of water through a height of 10 m in 5 seconds if the efficiency of the engine is 60% calculate the power of the engine in kW

Answer 2

Answer:c-40%

power =750w(input power)

efficiency= output power /input power

output power=F.d=300x10x6/60=300

efficiency=300/750x100=40%