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Thermodynamics — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsThermodynamics1 Mark
MCQ
An ideal heat engine working between temperature $T$ and $T$ has an efficiency $\eta$, the new efficiency if both the source and sink temperature are doubled, will be
  • A
    $\frac{\eta}{2}$
  • ✓
    $\eta$
  • C
    $2 \eta$
  • D
    $3 \eta$
✓

Answer

Correct option: B.
$\eta$
(b) In first case $\eta_1=\frac{T_1-T_2}{T_1}$In second case $\eta_2=\frac{2 T_1-2 T_2}{2 T_1}=\frac{T_1-T_2}{T_1}=\eta$

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