Q. Choose the incorrect statement from the following S1 : The efficiency of a heat engine can be 1, but the coefficient of performance of a refrigerator can never be infinity S2 : The first law of thermodynamics is basically the principle of conservation of energy S3 : The second law of thermodynamics does not allow several phenomena consistent with the first law S4 : A process, whose sole result is the transfer of heat from a colder object to a hotter object is impossible
A) S1
B) S3
C) S2
D) S4
Explanation
(a) Efficiency of a heat engine, $\eta = 1 - \frac{T_{2}}{T_{1}}$
For $\eta = 1(i.e.,\ 100\%)$ either $T_{1} = \infty$ or $T_{2} = 0\ K$
As source at infinite temperature or sink at $0\ K$ are not attainable, therefore heat engine cannot have efficiency 1
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.