The efficiency of anything can be determined by making a comparison between
the input and the output. So it's always output divided by input. The numerical
value thus produced is the efficiency as a decimal. To convert to percent move
the decimal point two to the right and add the % sign. If you happen to make an
error in setting up the formula, you will get an efficiency greater than 100%
which is not accurate. Just flip the numbers to get on the correct formula.
Just to use a few numbers to make the description better, if you put 100
units into something and get 80 units out, then the efficiency of 80 divided by
100 or .8 or 80%.
The units can be any unit of measurement.
In real life a machine or circuit, or pretty much anything can not produce
more than 100%. And no more than 100% can be put in. How basketball players give
110% is not calculable with mathematics.
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