Kelvin-Planck
Statement ( Second law of thermodynamics)
It is impossible to devise a
cyclically operating device, which produces no other effect than the extraction
of heat from a single thermalย
reservoirย and delivers an equivalent
amount of work.ย
Heat engine with single thermal reservoir is not possible.
For a 1-T engine the thermal efficiency h=W/Q=1. No heat
engine can have efficiency equalย ย to unity.
Secondย
law not only identifies the direction of process, it also asserts that
energy has qualityย ย as well as quantity.