Question

State the two forms of the second law of thermodynamics.

Answer 1

1. Kelvin–Planck statement: Heat QH cannot be taken out of a hot reservoir and used in its whole for labour W. It is necessary for QC to exhaust (give away) some of its heat to a cold reservoir. This rules out the development of an ideal heat engine.
2. Clausius statement: Heat cannot transfer from a colder body to a warmer body unless some effort is made to do this. This rules out the creation of the ideal refrigerator.