What are the Kelvin-Planck and Clausius statements?

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Kelvin-Planck and Clausius statements are two fundamental principles of thermodynamics.

Kelvin-Planck statement: It is impossible to construct a device that operates in a cycle and produces no effect other than the extraction of heat from a single reservoir and the performance of an equivalent amount of work.
Clausius statement: It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a colder body to a hotter body without the input of work.
These statements are based on the second law of thermodynamics and are crucial in understanding the limitations of heat engines and refrigerators.
Examples: A refrigerator cannot cool a room without consuming electricity (violating the Kelvin-Planck statement) and a heat pump cannot transfer heat from a cold outdoor environment to a warmer indoor space without the input of work (violating the Clausius statement).

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