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How do you calculate the energy efficiency of a device?

Answer 1

By definition, efficiency of a device or system is the ratio of power output to power input. #eta=(P_(out))/(P_(i n))#.

But since power is the rate of doing work, or the rate of energy transfer, #P=W/t#, and both the output and input systems operate simultaneously for the same duration of time, we may also give the efficiency as the ratio of the energy output to he energy input. #eta=W_(out)/W_(i n)#.

Since in all cases #W_(out)<=W_(i n)#, we ofteh multiply the efficiency #eta# by #100# in order to express it as a percentage

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Answer 2

Jose Arroyo

To calculate the energy efficiency of a device, you can use the formula:

Energy Efficiency (%) = (Useful energy output / Total energy input) x 100

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.