First law of thermodynamics

The First Law of Thermodynamics is simply the Law of Conservation of Energy, which states that:

 “Energy can neither be created nor destroyed, although it may be converted from one form to another.”

This law is purely a result of experience. A number of other statements have also been given to the law; the important ones are as follows;

·         The total energy of an isolated system remains constant although it may undergo transformation from one form to another.

·         Whenever certain quantity of some energy disappears, an exactly equivalent amount of some other form of energy must be produced.  

·         It is impossible to construct a perpetual motion machine i.e. machine which would produce work continuously without consuming energy (Helmholtz, 1847).