Efficiency of Carnot engine, η=40%=0.4 Temperature of source T1=500K Temperature of sin‌k‌T2=T Desired efficiency, η=60%=0.6 Temperature of sink T2=T Temperature of source T1= ? For case 1 Efficiency, η=1−
T2
T1
=1−
T
500
⇒
4
10
=
500−T
500
⇒ 200=500−T ⇒ T=300K For case 2 Efficiency, η2=1−