In which example does entropy increase?
i. a piece of fruit freezes in liquid nitrogen.
ii. librarians put library books back onto shelves at the end of the day.
iii. liquid nitrogen boils in a beaker at room temperature.
iv. dry ice sublimes.
v. a balloon collapses as its contents cool in liquid nitrogen.

Explanation:

Entropy -

In a system, the randomness is measured by the term entropy .

Randomness basically refers as a form of energy that can not be used for any work.

The change in entropy is given by amount heat per change in temperature.

entropy increases as the randomness increase ,

and ,

entropy decrease as the randomness decreases .

I. A piece of fruit freezes in liquid nitrogen.

randomness decreases , and so entropy decrease .

II. Librarians put library books back onto shelves at the end of the day.

randomness decreases , and so entropy decrease .

III. Liquid nitrogen boils in a beaker at room temperature.

change in state from less random liquid to gas , randomness increases , hence entropy increases

IV. Dry ice sublimes .

change in state from less random solid to gas , randomness increases , hence entropy increases .

V. A balloon collapses as its contents cool in liquid nitrogen .

cooling process , reduces the randomness , hence , entropy decreases .

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

it's c (engineer's do their work with mechanical stuff not on any living being)