### Entropy

Entropy is an important thermodynamic property of a working substance, which increases with the addition of heat; and decreases with its removal. As a matter of fact, it is tedious to the term Entropy. But it is comparatively easy to define change of entropy of a working substance. Over small range of temperature, the increase or decrease of entropy, when multiplied by the absolute temperature, gives the heat absorbed or rejected by the working substance. Mathematically, heat absorbed or rejected by the working substance,

δQ = T dS

where

T = Absolute temperature, and
dS = Increase or decrease in entropy.

Theoretically, the entropy of a substance is zero at absolute zero temperature. Hence, in entropy calculations, some convenient datum should be selected from which measurement may be made.

It may be noted that water at 0° C is assumed to have zero entropy, and changes in its entropy are reckoned from this temperature.

1. What is the entropy of universe then..?explain

1. entropy of universe is increasing day by day

2. Same of my note book cope ,so thankful to you

3. Same of my note book copy, so thankful to you

4. global warming

### Are Engineers Favourite Among Girls?

What do girls think about men who are engineers and what type of engineers are most favourite among girls? A survey was conducted by a team of aboutmech with members chosen from different countries. Each team member carried out a neutral survey in his/ her country to evaluate what females think about most of the engineers from different engineering branches. An overview of different questions asked in survey is given below: Question: Which male engineers do you find more attractive as a husband? Almost 50% women voted for mechanical engineers to be the most attractive husbands among other engineers. So mechanical engineers are most favourite among girls as a husband. They find them more trustworthy, intelligent, and creative. A married women from California said, “If your husband is a mechanical engineer, he will help you in everyday tasks. Because mechanical engineers are good team players and they have creative ideas about everything.” Which male engineers do you find more