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Thermodynamics — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsThermodynamics1 Mark
MCQ
A scientist says that the efficiency of his heat engine which operates at source temperature $127^{\circ} \mathrm{C}$ and sink temperature $27^{\circ} \mathrm{C}$ is $26 \%$, then
  • ✓
    It is impossible
  • B
    It is possible but less probable
  • C
    It is quite probable
  • D
    Data are incomplete
✓

Answer

Correct option: A.
It is impossible
(a) $\eta_{\max }=1-\frac{T_2}{T_1}=1-\frac{300}{400}=\frac{1}{4}=25 \%$
So $26$efficiency is impossible

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