The temperature of source and sink of a heat engine are 127^ C and 27^ C , respectively. An inventor claims its efficiency to be 26 \% , then

Correct answer: A. it is impossible Efficiency of heat engine is =1-(T_2)/(T_1) or =(T_1-T_2)/(T_1) Here, T_1=273+127=400 K aligned & T_2=273+27=300 K & =(400-300)/(400)=(100)/(400)=0.25=25 \% aligned Hence, 26 \% efficiency is impossible for a given heat engine.

JIPMER 2017

Exam: JIPMER
Year: 2017
Subject: Physics
Chapter: Thermodynamics

JIPMER 2017 · Physics · Thermodynamics

The temperature of source and sink of a heat engine are 127^ C and...

The temperature of source and sink of a heat engine are

127^{\circ} \mathrm{C}

and

27^{\circ} \mathrm{C}

, respectively. An inventor claims its efficiency to be

26 \%

, then

Options

Ait is impossible
Bit is possible with high probability
Cit is possible with low probability
DData are insufficient

Correct answer

A. it is impossible

Step-by-step solution

Efficiency of heat engine is

\eta=1-\frac{T_2}{T_1} \text{

} \eta=\frac{T_1-T_2}{T_1}

Here,

T_1=273+127=400 \mathrm{ K}

\begin{aligned} & T_2=273+27=300 \mathrm{ K} \\ & \therefore \eta=\frac{400-300}{400}=\frac{100}{400}=0.25=25 \% \end{aligned}

Hence,

26 \%$ efficiency is impossible for a given heat engine.

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