Question

Match the following statement:

Column 1	Column 2
A device used for recording atmospheric pressure.	Torricellian vacuum
An empty space inside the barometric tube above mercury.	normal pressure
76 cm of the vertical height of mercury at sea level.	mercury
Weather forecast when atmospheric pressure suddenly drops and air is moist.	107.4 m
Weather forecast when atmospheric pressure does not change.	triangulation method
The height of a place when the mercury level falls by 1 cm.	barometer
A method used for measuring very large distances.	rain storm
A liquid commonly used in cistern barometer.	fair weather

Answer 1

Part- A

1. The pressure exerted by air due to its weight on the surface of the earth is called atmospheric pressure.
2. A device used for the measurement of atmospheric pressure is called a barometer.
3. It was firstly designed by an Italian scientist Torricelli.

Thus, (A)- (VI)

Part- B

1. A barometer consists of a narrow glass tube.
2. The tube is filled with pure and dry mercury so that no air bubbles are left in the tube.
3. At the open end, we place our thumb tightly then it is inverted in a bowl containing mercury.
4. The thumb is removed from the open end under the level of mercury in the bowl.
5. It is observed that some mercury moves down thereby creating an empty space.
6. This space is called the Torricellian vacuum.

Thus, (B) - (I)

Part- C

1. At sea level, the atmospheric pressure is 76cm of mercury.
2. This is called the normal atmospheric pressure.

Thus, (C) - (II)

Part- D

1. If the pressure at a place falls suddenly, it could result in a dust storm or rainstorm, depending on how much water vapour is in the air.
2. If the air contains water vapour, it will result in a rainstorm.

Thus, (D) - (VII)

Part- E

1. At a particular place on the surface of the earth, the atmospheric pressure is expected to be constant.
2. But it does not happen in most places on the earth.
3. If the atmospheric pressure of any place does not change it suggests fair weather at that place.

Thus, (E) - (VIII)

Part- F

1. The normal atmospheric pressure is 76 cm of mercury at sea level.
2. It has been found that compared to sea level the atmospheric pressure does not remain constant always.
3. It decreases by 1 cm for a gain of height of 107.36 m (almost 107.4 m).

Thus, (F) - (IV)

Part- G

1. There are various methods used for the measurement of the distance between two points.
2. For measuring large distances, measuring tape is used.
3. For measuring very large distances, the triangulation method is used.

Thus, (G) - (V)

Part- H

1. A barometer is also known as a cistern barometer.
2. It has a narrow glass tube filled with perfectly pure and dry mercury so that no air bubble is left inside the tube.

Thus, (H) - (III)

Therefore, the correct answer is A-VI, B-I, C-II, D-VII, E-VIII, F-IV, G-V and H-III