Thermodynamics & thermodynamic systems

In this post we are going to discuss some important questions from the topic ” Thermodynamics & thermodynamic systems ” which will cover the complete topic.

1. What is thermodynamics ?

“Thermodynamics is that branch of physics which is mainly concerned with the transformation of heat into mechanical work”

Or

“The branch of physics devoted to study of heat & related phenomenon”

Or

“Thermodynamics is a branch of science concerned with heat and temperature and their relation to energy and work”

Thermodynamics constitutes a very subtle study in physics, chemistry and engineering and has innumerable applications.It is based upon two general laws of nature which governs the conversion of heat into work & vice versa.
The first law represent connection between heat and mechanical work. On the other hand the second law depicts the manner in which these energy change take place.Thermodynamics deals with macroscopic (large scale) properties and do not go into the detailed structure.

3. Thermodynamics Systems

(i) What is System ?

“A definite quantity of matter bounded by some closed surface is known as system”.

(ii) What is surrounding ?

“Anything outside the system which can exchange energy with the system & has direct bearing on the behavior of system is called surrounding”.

(iii) What do you mean by state of a system ?

“It is defined by an ascribing value to a sufficient number of variables”.

In thermodynamics, state of system can be represented by specifying it’s pressure (P) , Volume (V) and temperature (T) provided the system in equilibrium.

(iv) What are thermodynamic parameters ?

“Those parameters describing the state of a system are called thermodynamic parameters or thermodynamic variables or thermodynamic coordinates.These are pressure (P) , Volume (V) , temperature (T) “

(v) Discuss the types of thermodynamics systems.

General thermodynamic systems are gases, vapour steam, solid, liquid, surface films, stretched wires, thermocouples, magnetic materials, electric cells,etc.

Systems are of three kind :

Open System :- “Systems which can exchange both matter & energy with surrounding are known as open systems” e.g. tea in a cup

Closed System:- “System which can exchange only energy (not matter) with surrounding are known as closed system” e.g. tea in a cup covered with lid.

Isolated System:- “If a system is not influenced in any way by it’s surrounding, it is said to be isolated”. An isolated system exchanges neither matter nor energy with its surrounding. e.g. tea in a thermoflask.
Some other related topics are :

• First Law of Thermodynamics & Its limitations

• Heat Engine & It’s Components

In this article we have discussed Thermodynamics & thermodynamic systems. We will be back with more articles.