Q. An engine has an efficiency of 1/6. When the temperature of sink is reduced by 62°C, its efficiency is doubled. Temperature of the source is
A) 37°C
B) 62°C
C) 99°C
D) 124°C
Explanation
[Solution from source] 1/6 = 1 − T₂/T₁ and 1/3 = 1 − (T₂ − 62)/T₁. Subtracting, 62/T₁ = 1/6, so T₁ = 372 K = 99°C. 62°C confuses the temperature drop with the source temperature. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.