(a) Calculate the theoretical efficiency for an Otto-cycle engine...

Question

(a) Calculate the theoretical efficiency for an Otto-cycle engine with g = 1.40 and r = 9.50.

Accepted Answer

Welcome back everybody. We are taking a look at an internal combustion engine and we are told that it has a compression ratio of 12.5 and a heat capacity ratio, which I will just denote by gamma of 1.4. And we are asked to find what the ideal efficiency of this engine is. Well, there's a formula for this. We have that our efficiency is equal to one minus R. To the power of one minus gamma. So let's just go ahead and plug in those values here. This is going to be one minus 12.5 to the power of one minus 1.4. When you plug this into your calculator, you get 0.636. But of course we need to express this as a percentage. So E. is then equal to 63.6%, which corresponds to our answer choice of B. Thank you all so much for watching. Hope this video helped. We will see you all in the next one.

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