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 only result is to transfer heat from a colder to a hotter object, is impossible.

Question

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 only result is to transfer heat from a colder to a hotter object, is impossible.

Medium

Download our app for free and get started

Solution

Efficiency of heat engine, $\eta=1-\frac{\mathrm{T}_{2}}{\mathrm{T}_{1}}$

For $\eta=1 \text { (i.e. } 100 \%)$ either, $\mathrm{T}_{1}=\infty$ or $\mathrm{T}_{2}=0 \mathrm{K}$

As source at infinite temperature or sink at $0\, \mathrm{K}$ are not attainable.

Therefore heat engine cannot have efficiency $1$

Download our app
and get started for free