Q.
A carnot engine whose efficiency is 40%, receives heat at 500K. If the efficiency is tobe 50%, the source temperature for the same exhaust temperature is
We know that, efficiency of a Carnot engine is given by η=(1−T1T2)
Given, η1=0.4 and T1=500K
(temperature of source)
So, 0.4=1−500T2 ⇒500T2=1−0.4=0.6 ⇒T2=0.6×500=300K
(temperature of sink)
Now, in the second gas, η=0.5 and T2=300K ∴0.5=(1−T1300) ⇒T1300=1−0.5=0.5 ⇒T1=0.5300=600K