Lecture 38 : Second Law: Illustrative Problems

"1. Minimum work input to a heat pump
2. Maximum work output from a heat engine"

[@abdullahialkafi6248]

22:16 how does the line A'=AKTh^4 come?

[@alphaace-pubgmobile9917]

29:45 can someone explain why maximum work is dw/dh=0

[@blackheart6897]

In the question it was asked to find TH such that W is max

[@Gasturbine]

22:16 not getting

[@dhruvsaxena9740]

Simply differentiate the function of A w.r.t. TL and put it equal to zero. You will get it.🙃🙃

[@Gasturbine]

@@dhruvsaxena9740 well mathematically U r correct but mechanically u r not as sir did derivatives w.r.t(Th/TL) not only w.r.t TL. By the way thanks for your reply.

[@dhruvsaxena9740]

@@Gasturbine use Tl(as x) as variable not Th/Tl, that will make it easy

[@Gasturbine]

@@dhruvsaxena9740 yes I got Ur point..and I did it in Ur way...but This is not correct approach...I think.

[@pranavkulkarni150]

@@Gasturbine well you can assume any variable for differentiation, provided the limits are changed accordingly