Four engines are working between Which one has maximum efficiency ?

1.	Four engines are working between Which one has maximum efficiency ?
Answer» 100 K and 80 K 40 K and 20 K 60 K and 40 K 120 K and 100 K Solution :EFFICIENCY, `ETA = 1 - (T_(2))/(T_(1)) = (T_(1) - T_(2))/(T_(1))` In all the given four cases, `T_(1) - T_(2) = 20 K` `:. eta` is highest when `T_(1)` is LOWEST. `:.` At option (b), 40 K and 20 K, has maximum efficiency.

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