Law of thermodynamics

February 12, 2021

Law of Thermodynamics

Thermodynamics - thermodynamics is a branch of science which deals with the energy transfer or heat converted into work.

There are four basic law of thermodynamics -

1) first law of thermodynamics

2) second law of thermodynamics

3) third low af thermodynamics

4) zeroth law of thermodynamics

1) first law of thermodynamics - According to first law of thermodynamics the energy can nither be created nor be destroyed but it converted from one form of energy to other form of energy

Q = delta U + W

Q = total heat

Delta U = total internal energy change

W = weak output

Second law of thermodynamics - the second law of thermodynamics is comprises two statement -

1) Kelvin - Plank statement

2) Clousious statement

Kalvin - plank statement - According to Kelvin plank statement it is impossible to construct engine which give 100% efficiency, there are no other effect expect work.

Ex - engine, boiling, water, etc

Clousious statement - it is impossible to construct a device which operate on cycle and produce an other effect them the transfer of heat from a colder body to hoter body.

According to this law heat engine can have 100% efficiency weakly impossible to achieved.

3) third law of thermodynamics - for third low of thermodynamics these are three point which are necessary for better understanding of third low of thermodynamics.

* Entrophy - majar of disorder or degree of randomness .

ds = dQ/T

* Absolute zero - Colder possible temperature zero Kalvin or (-273.15 degree Celsius) or (-459.66 degree F )

* Perfect Crystal - A perfect crystal is a crystal that contains no point, line, or planar defects. There are a wide variety of crystallographic defects. The hypothetical concept of a perfect crystal is important in the basic formulation of the third law of thermodynamics.

**) Combind statement - according to third low of thermodynamics the Entrophy of crystalline substance is zero at absolute zero temperature.

T = -273.15 degree Celsius

= 0 Kalvin

The third law of thermodynamics also called "Nernst low "

4) Zeroth law of thermodynamics - if two system are in equilibrium with a third system, they must be in thermal equilibrium in each other

According to zeroth law of thermodynamics if body A is in thermal equilibrium with C and B is in thermal equilibrium with C then body A and B are also in thermal equilibrium separately.