For a wide range of engineering plant like steam turbines, reciprocating engines, turbo-jets, rockets, combustion systems etc., we are concerned with the transfer of heat and work. In many cases the objective is to convert one form of energy to another. Thermodynamics is science of energyandentropy. “Thermodynamics is the science that deals with heatand workand thoseproperties of substances that bear a relation to heat and work.”