Laws of Thermodynamics [Zeroth, First, Second & Third]

 Laws of Thermodynamics:

What is heat?

The transfer of energy from a higher temperature object to a lower object is known as heat. The transfer of heat energy is from a higher-temperature substance to a lower-temperature substance.

"उच्च ताप वाली वस्तु से निम्न वस्तु में ऊर्जा के स्थानान्तरण को ऊष्मा कहते हैं। ऊष्मा ऊर्जा का स्थानांतरण उच्च तापमान वाले पदार्थ से निम्न तापमान वाले पदार्थ में होता है।"

The four laws of thermodynamics are as follows.

1. Zeroth Law of Thermodynamics
2. First Law of Thermodynamics
3. Second Law of Thermodynamics
4. Third Law of Thermodynamics

So, let me give you a quick rundown of everything!

Zeroth Law of Thermodynamics:

According to Zeroth's Law of Thermodynamics "if when body 'A' is in thermal equilibrium with body 'B' and separately with body 'C,' then B and C will be in thermal equilibrium with each other".

"थर्मोडायनामिक्स के सुन्याँक  नियम के अनुसार "यदि बॉडी 'A ' बॉडी 'B ' के साथ थर्मल संतुलन में है और अलग-अलग बॉडी 'C ' के साथ है, तो B  और C  एक दूसरे के साथ थर्मल संतुलन में होंगे।"

Zeroth Law

Two systems must be in thermal equilibrium with each other if they are in thermal equilibrium with a third system.

First Law of Thermodynamics:

• The first law of thermodynamics is often known as the law of energy conservation.
• The network transfer equals the net heat transfer during any cyclic process.

" किसी भी चक्रीय प्रक्रिया किया गया कुल कार्य उस चक्रीय प्रक्रिया के दौरान हुई कुल हीट ट्रांसफर के बराबर होता है।"

First Law for Cyclic Process

• When a system goes through a change of state that involves both heat and work transmission, the net energy transfer is stored or accumulated inside the system.
• If, as indicated in the picture, 'Q' is the quantity of heat transmitted to the system and 'W' is the amount of work transferred from the system during the operation.
• The system will store the net Energy Transfer (Q-W). Internal Energy is the name given to the energy in storage that is neither heat nor work.

Q-W= ΔE

Second Law for Non-Cyclic Process

• If the process involves more energy transfer quantities (i.e. Energy transfer and Work transfer), as indicated in the diagram. The following is the equation.                    

   (Q2 +Q3 -Q1)= ΔE +(W2+W3-W1-W4)

Second Law of Thermodynamics:

• The second law of thermodynamics states that the entire heat energy cannot be turned into work and that some of it must be rejected to the environment.
• "ऊष्मप्रवैगिकी का दूसरा नियम कहता है कि संपूर्ण ऊष्मा ऊर्जा को पूरी तरह से  कार्य में नहीं बदला जा सकता है, इसमें से कुछ उष्मा पर्यावरण में चली जाती है ।"
• The diagram below depicts a hypothetical machine in which heat is fed from a hot reservoir, work is performed on the environment, and the remainder is rejected to a cold reservoir (mostly the atmosphere).

Second law of Thermodynamics

• Work is considered high-grade energy, whereas heat is considered low-grade energy. It is impossible to convert all low-grade energy into higher-grade energy in a cycle.
• There another statements of the 2nd Law of Thermodynamics those is:

Classius Statement:

• It is impossible for a self-acting machine working in a cyclic process to transfer heat from a body at a lower temperature to a body at a higher temperature without the assistance of any external factor.
• "चक्रीय प्रक्रिया में काम करने वाली एक self-acting machine के लिए किसी बाहरी कारक की सहायता के बिना कम तापमान की बॉडी से उच्च तापमान वाली बॉडी में उष्मा  स्थानांतरित करना असंभव है।"

Or

• It's impossible to build a refrigerator that's sole goal is to absorb heat from a low-temperature reservoir and transfer it to a high-temperature reservoir without requiring any work.

Third law of Thermodynamics:

• The third law of thermodynamics indicates that at absolute zero, the entropy of a system is a well-defined constant.
• "ऊष्मप्रवैगिकी का तीसरा नियम कहता है कि पूर्ण शून्य ताप  पर, एक सिस्टम की एन्ट्रापी स्थिर रहती है।"
• "The heat absorbed divided by the temperature of the reversible process equals the change in entropy."

ΔS = Q/T

Q= Heat Absorbed

T= Temperature

ΔS= Change in Entropy

The lower the entropy, the less energy is available to conduct work in your system.

"एन्ट्रापी जितनी कम होगी, आपके सिस्टम में काम करने के लिए उतनी ही कम ऊर्जा उपलब्ध होगी।"