Laws of thermodynamics

1. Fundamental laws that helps you to get better understanding with physics concepts Laws of thermodynamics

2. We have four laws of thermodynamics, which define fundamental physical quantities i.e., temperature, energy, and entropy that characterize thermodynamic systems and their behaviour under various circumstances. They are Zeroth law of thermodynamics First law of thermodynamics Second law of thermodynamics Third law of thermodynamics

3. Zeroth law of thermodynamics If two systems are in thermal equilibrium with a third system, they must be in thermal equilibrium with each other. This law describes an empirical parameter, the temperature, as a property of a system such that systems in thermal equilibrium with each other have the same temperature.

4. First law of thermodynamics The increase in internal energy of a closed system is equal to the heat supplied to the system minus work done by it. First law of thermodynamics is also known as the law of conservation of energy. This states that energy can be neither created nor destroyed. However, energy can change forms, and energy can flow from one place to another. The total energy of an isolated system does not change. dU system =Q - W

5. Second law of thermodynamics The entropy of any isolated system almost never decreases. Such systems spontaneously evolve towards thermodynamic equilibrium that is the state of maximum entropy of the system. Equivalently, perpetual motion machines of the second kind are impossible. According to this law, in a reversible heat transfer, an element of heat transferred, δQ , is the product of the temperature (T) and its entropy (S) dQ = TdS

6. Third law of thermodynamics The entropy of a system approaches a constant value as the temperature approaches absolute zero. At zero temperature the system must be in a state with the minimum thermal energy. This statement holds true if the perfect crystal has only one state with minimum energy. Entropy is related to the number of possible microstates according to: S = k B ln Ω Where S is the entropy of the system, k B Boltzmann's constant, and Ω the number of microstates These laws are very helpful to get better understanding with physics Concepts.