What is the difference between efficiency and gain?
can anyone explain the difference between efficiency and gain with detail?
please give me technical answer ..
Replies
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Ramani Aswath
Input -> System -> Output
Output/Input x 100 = %Efficiency
1 kg diesel put into an engine say gives an output of 4.6 KWHr. ! kg diesel gives 10000 KCal energy. 4.6 KWHr is equal to 4000 KCals.
So, Efficiency = 100x(4000/10000)= 40%
Gain = Input-Output
There is 5 litres water at 50 deg C in an open vessel on a stove. It is losing 5 KCal/min by radiation and evaporation. If 10 KCal/min is given to the vessel by the stove, then the net heat input into the water is 10-5=5KCal/min.
Gain = 10-5 =5 Kcal/min. The water will heat up at the rate of 5 deg C/minute.
These are rather quick and dirty examples.
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Ramani Aswath
Take the water example 10 KCal/ Min was put in. What was the output? Not the 5 Kcal lost by radiation and evaporation but the % KCal gained by the water. So efficiency is 100x(5/10)=50%.
Unfortunately, the loss = gain so the % was the midpoint in this case. The important thing is to know what the actual output is.
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Ramani Aswath
I apologise for an arithmetic error in my first post. 5 Kcal/min added to 5 litres of water will increase the temperature by 5/5=10C/min and not 50C.
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