Laws of thermodynamics : Basic definition law of thermodynamics

Laws of thermodynamics : Basic definition law of thermodynamics, interview questions

Laws of Thermodynamics of Mechanical Engineering interview questions

So everyone can learn in engineering of subject like Engineering thermodynamics. Remeber of law of themodymamics is important for interview questions.

Let's start to again learning and improving yourself.

In my case when I am getting a job in mechanical field, When I remember before go to interview questions,and some basic of first law of thermodynamics, themodymamics third law,zeroth law of themodymamics etc. And some important subject like strength of Materials, Design of machine etc. Subject basic questions for interview in job.

So start up again...

First question in mind like that,

1. What are the 1st 2nd and 3rd laws of thermodynamics?
2.  What does the law of thermodynamics state?
3. What are the 4 laws of thermodynamics?
4. What does the 2nd law of thermodynamics state?
5. What is the 3rd law of thermodynamics in simple terms?
6. What are the first three laws of thermodynamics?
   
   

So below are the answers of alll questions of law of thermodynamics,

• What is mean by thermodynamics? application or example of thermodynamics system.

Thermodynamics is the science of energy transfer and its effect on the physical properties of substances. It is based upon observations of common experience which have been formulated into thermodynamic laws. These laws govern the principles of energy conversion. The applications of the thermodynamic laws and principles are found in all fields of energy technology,notably in steam

1. nuclear power plants, 
2. internal combustion engines, 
3. gas turbines,
4. air conditioning, 
5. refrigeration, 
6. gas dynamics, 
7. jet propulsion, 
8. compressors, 
9. chemical process plants,
10. direct energy conversion devices

1. What is first law of thermodynamics? And what also known ?

The first law of thermodynamics, also known as Law of Conservation of Energy, it can be stated that energy cannot be created or destroyed, but only changed from one form into another or transferred from one object to another.

Reference book..of R.k.Rajput 

“When a system undergoes a thermodynamic cycle then the net heat supplied to the system from the surroundings is equal to net work done by the system on its surroundings.

1. What is the 2nd law of thermodynamics?

Ans. In all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state, This is second law of thermodynamics

Or

It can be stated that the entropy of any isolated system always increases.

Or

Kelvin-Planck Statement for 2nd law of thermodynamics..

“It is impossible to construct an engine, which while operating in a cycle produces no other effect except to extract heat from a single reservoir and do equivalent amount of work”.

Or

Clausius Statement for 2nd law of thermodynamics:

“ second law of thermodynamics is  impossible for a self acting machine working in a cyclic process unaided by any external agency, to convey heat from a body at a lower temperature to a body at a higher temperature”.

So next question is 

•  what is 3rd laws of thermodynamics?

Ans.the entropy of a system approaches a constant value as the temperature approaches absolute zero.The entropy of a system at absolute zero is typically zero .

The entropy of a system approaches a constant value as the temperature approaches absolute zero.With the exception of non-crystalline solids (glasses) the entropy of a system at absolute zero is typically close to zero.

so there are we learn threelaws of thermodynamics, which is most important Mechanical engineers.

 

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