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Thermodynamics — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsThermodynamics1 Mark
MCQ
For which combination of working temperatures the efficiency of Carnot's engine is highest
  • A
    $80 K, 60 K$
  • B
    $100 K, 80 K$
  • C
    $60 \mathrm{~K}, 40 \mathrm{~K}$
  • ✓
    $40 K, 20 K$
✓

Answer

Correct option: D.
$40 K, 20 K$
$\eta=1-\frac{T_2}{T_1}$.
for $\eta$ to be max. ratio $\frac{T_2}{T_1}$ should be min.

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