CBSE Class 8 Answered

Hi Adwait,

Zeroth law of thermodynamics: When the thermodynamic systems A and B are separately in thermal equilibrium with a third thermodynamic system C, then the systems A and B are in thermal equilibrium with each other also.

First Law of thermodynamics: Whenever heat is added to a system, it transforms to an equal amount of some other forms of energy.

dQ = dU + dW

Second law of thermodynamics: 

Kelvin Planck statement: It is impossible to construct a heat engine which would absorb heat from a reservoir and convert 100% of the heat absorbed into work.

Clausius statement: It is impossible to design a self acting machine unaided by external agency which would transfer heat from a body at a lower temperature to another body at a higher temperature.