1200K
750K
600K
Efficiency of carnot engine cannot be made larger than 50%
For the 1st case, Efficiency = η = (1 - T1/T2) × 10040 = (1 - T1/500) × 100T1 = 300KFor the 2nd case,η = (1 - T1/T2) × 100 = 60T2 = 750K