Question

If you have a device that has an energy efficiency of 0.4 and you put in 100 units of energy, how many units of useful energy will you get out of it?

Answer 1

Is it 0.4 %?

Answer 2

im not sure thats why i asked):

Answer 3

If it's 0.4%, the answer will be 0.4.. else it will be 40.

Answer 4

I believe the efficiencies are like coefficients, they are ready to multiply as is. I think it's 40.