Q. A Carnot's engine works between a source at a temperature of $27℃$ and a sink at $- 123℃$. Its efficiency is
A) 0.5
B) 0.25
C) 0.75
D) 0.4
Explanation
(a) $T_{1} = 27℃ = (27 + 273)K = 300\ K$
$T_{2} = - 123 + 273 = 150\ K$
$\eta = 1 - \frac{T_{2}}{T_{1}} = 1 - \frac{150}{300} = 0.5$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.