The question asks about the efficiency of a reversible engine, and the correct concept or theorem associated with it. This is a question related to thermodynamics, which is crucial in many fields, including pharmaceutical engineering.
To find the efficiency of a reversible engine, we refer to the Carnot theorem. The Carnot theorem states that no engine operating between two heat reservoirs can be more efficient than a Carnot engine operating between those same reservoirs. The efficiency of a Carnot engine depends solely on the temperatures of the two reservoirs.
The efficiency \( \eta \) of a Carnot engine is given by the formula:
\(\eta = 1 - \frac{T_C}{T_H}\)
where \( T_H \) is the absolute temperature of the hot reservoir, and \( T_C \) is the absolute temperature of the cold reservoir.
Now, let us briefly explore why other options are incorrect:
Thus, the correct answer to the question regarding the efficiency of a reversible engine is attributed to the Carnot theorem.
Choose the correct match of laxative and its Mechanism of Action (MOA):

Match the following:
(P) Schedule H
(Q) Schedule G
(R) Schedule P
(S) Schedule F2
Descriptions:
(I) Life period of drugs
(II) Drugs used under RMP
(III) List of Prescription Drugs
(IV) Standards for surgical dressing