Question

A machine has an efficiency of $25$%. Energy is fed into the machine at the rate of $1kw$. The output power of machine is:-

• A. $40W$
• B. $250W$
• C. $750W$
• D. $25W$

Answer 1

The correct option is B $250W$

25%efficiency means machine gives an output of 25 when input is 100

In given question input is 1kW or 1000w.

Output = 25% of input

So the output= 25% of 1kw

= 250w