The laws of thermodynamics define the fundamental physical quantities like energy, temperature and entropy that characterise thermodynamic systems at thermal equilibrium. The laws represent how these quantities behave under various circumstances.

How many laws of thermodynamics are there?

There are four laws of thermodynamics and are given below:

• Zeroth law of thermodynamics
• First law of thermodynamics
• Second law of thermodynamics
• Third law of thermodynamics