What are the Terms used in Thermodynamics

following are the terms mostly used in thermodynamics students always neglect these terms which having high demand in Competitive world.

 System:

It is defined as the quantity of matter or region in the space where our attention is focused.

system could be anything like particular quantity of substance or defined space in the flow region considerd in order to study the process.

 surrounding: 

 Every thing external to system is known as surrounding.

 

Boundary:

system is separated from surrounding by its boundary through which energy may enter or leave.

                                

 NOTE:

1.Real boundary does not allow mass transfer through it.

2.Imaginary boundary allows mass transfer through it.

3.To get work from close system minimum one boundary should be moving.

4.Boundary may be adiabatic(no heat transfer) and diathermal (resistance is zero).

 

  Types of system:

There are three types of systems

1.closed system:

In closed system,there is no any mass transfer between system and surrounding.

No mass can enter or leave the system, it means mass of the system is constant and fixed mass known as control mass system.

In closed system,heat interaction or work interaction may take place between system and surrounding.

examples:1.Rigid container

                 2.Piston and cylinder arrangement without valves.

2.open system:

In open system, mass interaction also take place along with energy interaction.

Analysis of open system is based on fixed region in space known as control volume system.

example:1.turbine

               2.compressor

               3.pump

3.Isolated system:

In this, neither mass nor energy may transfer between system and surrounding.

example:1.Perfectly insulated rigid container

               2.The best example for isolated system is universe

Thermodynamics properties:

properties are the characteristics by which system can be identified.

1.intensive properties:

it is defined as the properties independent of mass or size of the system.

examples:pressure,temperature, density, thermal conductivity etc.

note:

1.Ratio of two extensive properties are always intensive.

2.specific properties are intensive properties.

2.extensive proprties:

it is defined as the properties depends on the mass or size of system.

examples:mass,volume, entropy, enthalpy, electrical charge, magnetic field,etc.

Note:

 1.Properties are point or state function.

2. Properties are exact differential.