Question

A TV takes in 600J of electrical energy and gives out 300J of light, 240J of sound and 60J of heat energy (be careful here!). Calculate the efficiency.

Answer 1

Answer:

90%

Explanation:

The energy efficiency formula runs like efficiency = useful energy output/energy input * 100%.

The energy output here is 600 (300+240) and the input is 600J. However since its heat energy of 60 you won't include that. So you will input the output and the energy input in the formula and you will get 540/600=0.9

So your answer is 90%.

Sorry if its confusing, have a good day! :D