Laws of Thermodynamics


Role of Thermodynamics in Daily Life


That energy never perishes, that velocity never stops, neither it could be cut, nor it could be burn; neither it could be diluted, nor it could be dried. It is continuous, omnipresent, static, immovable and always existing.

This shloka clearly indicates about the First Law of Thermodynamics, “i.e., energy can neither be created nor destroyed.” It is conserved.

How 1st law came into existence

Different statements indicate the failure of experiments that could led to creation of energy.

There were attempts to produce energy in any form so that Law of Conservation of Energy could be failed and produced energy could be utilized for welfare of mankind. These attempts failed and the statements describing the failed experiments were called as Laws of Thermodynamics. Those different statements are as follows

  1. It is impossible to construct a machine that can produce more energy than the consumed by it. If such a machine will be possible in future, its motion shall be called the perpetual motion of first kind.
  2. In an open system, if some energy is evolved in one part of the system, the same amount of energy is consumed in another part of same system.
  3. In an isolated system, total energy remains constant but one form of energy can be converted into other form.
  4. In a closed system, the energy supplied (q) is used for increasing the internal energy (dE) and doing useful work (w).

dE = q + w

In the equation, the old sign conventions are to be used. For using new sign conventions, the + sign should be replaced by – sign.

2nd Law of Thermodynamics – Law of Helplessness of Mankind

Ist law failed as it could not tell direction, extent and conditions required in a spontaneous process.

Work – Heat (Spontaneous)

Heat – Work (Non Spontaneous)

Conversion of Heat into work was not possible completely.

Thanks For Reading

Jai Swaminarayan

Gaurav S Kaintura

12 May 2017


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