What are the Four Laws of Thermodynamics

Zeroth Law of thermodynamics:

When two systems are each in thermal equilibrium with a third system, then the two systems are also in thermal equilibrium with one another.

First law of thermodynamics:

    ➦ The heat and mechanical work are mutually convertible.

∮∂Q =∮∂W

    

➦ The energy can neither be created nor destroyed through it can be transformed from one form to another.

∂Q-∂W=dE

Second law of thermodynamics:

    ➦ Kelvin-Plank Statement: It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy from a single thermal reservoir into an equivalent amount of work.

    ➦ Clausius Statement: It is impossible for a self acting machine working on a cyclic process, to transfer heat from a body at a lower temperature to a body at a higher temperature without the aid of an external agency.

Third law of thermodynamics:

    ➦ The entropy of any pure substance is thermodynamic equilibrium approaches zero as the temperature approaches zero.