The Carnot efficiency is given by the relationship. =1(Tc/TH) where TH and TC represent the temperatures of the hot and cold reservoirs. a) Develop general expressions that one can use to assess the variation of the "efficiency" with TH while holding Tc constant, or with variation of Tc while holding TH constant. b) Represent the outcomes of your answer to part a in a graphical form. c) If you had the choice of changing either the TH or TC by same amount, what would you recommend for increasing the efficiency. Justify your answer. d) Comment on realistic achievability of your recommendation