Efficiency is the estimation of output power by any machine. A 12% efficient engine has an output provided by the input energy of the engine. Thus, option D is correct.
<h3>What is efficiency?</h3>
Efficiency is defined as the energy given by the machine, engine, or any system by utilizing the input power or energy. It is given as,
η = Output ÷ Input × 100%
It is used to know the ability of the machine to transfer the input energy to an external amount of work. The engine with 12% efficiency is said to have produced energy by utilizing the provided 12% input.
Therefore, option D. the 12% of input power is used by the engine to produce the energy.
Learn more about efficiency here:
brainly.com/question/22739880
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