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.
 dUsystem=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 = kBln Ω
Where S is the entropy of the system, kB Boltzmann's
constant, and Ω the number of microstates
These laws are very helpful to get better understanding
with physics Concepts.