Question

What is Thermodynamics? Explain.

Answer 1

Thermodynamics

The branch of Physics deal with the study of transformation heat energy into other forms of energy and vice-versa is called thermodynamics.

• Zeroth Law of Thermodynamics: If two bodies are separately in thermal equilibrium with third body, then first two systems will be in thermal equilibrium. 

• First Law of Thermodynamics: The amount of heat given to a system is used up in two ways: first to increase the initial energy and second to do external work. 

\(\Delta Q = \Delta U + \Delta W\)

First law of thermodynamics is direct consequence of law o conservation of energy. 

• Second Law of Thermodynamics: Two statements of this law are as follows 

(i) Kelvin-Planck Statement- It is impossible to construct an engine which will not produce any other effect other than extracting heat from a reservoir and performing an equivalent amount of work.

(ii) Clausius Statement- It is impossible for a self-acting machine, unaided by external agency to transfer heat from/to another a higher temperature.

Answer 2

Thermodynamics" comes from the Greek words "therme" which means heat and "dynamic" which means force, or power.

It is the study of the relations between heat, work, temperature, and energy. The laws of thermodynamics describe how the energy in a system changes.

1st Law of Thermodynamics - Energy cannot be created nor be destroyed. But it can change from one form to another.

2nd Law of Thermodynamics - For a spontaneous process, the entropy of the universe increases.

3rd Law of Thermodynamics - A perfect crystal at zero Kelvin has zero entropy.