Tag: air exerts pressure

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Questions Related to air exerts pressure

Multiple choice physics air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure wind and rain uneven heating of earth

The continuous spectrum is obtained when the incandescent substance is?

  1. In state of atomic vapour

  2. In solid state

  3. In state of molecular vapour

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

An incandescent light bulb produces a continuous spectrum because the source of the light is a metal filament (i.e. solid).

Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts the concept of bernoulli's principle air exerts pressure

In normal conditions, atmospheric pressure varies with__________ 

  1. Height

  2. Altitude

  3. Rainfall

  4. Temperature
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

 
  • Both atmospheric pressure and  the density of air decrease with altitude.
  • This is due to the fact that air molecules are constantly being pulled downwards (towards the center of the Earth) by Gravity.
  •  So, air molecules are tightly packed near the surface of the earth, compared to some higher altitude.

Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts the concept of bernoulli's principle air exerts pressure

The doldrums are in the _______________.

  1. Horse latitudes

  2. Sub-polar low pressure belt

  3. Equatorial low pressure belt

  4. Asteroid belt
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Due to the intense heating from sun rays around the equator, the air in this region gets hot and hence ascends upwards, thus creating a low pressure in the region. Hence it is the equatorial low-pressure belt and is also called doldrums as it is the region of extreme calmness, not as much as a breeze.

Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts the concept of bernoulli's principle air exerts pressure

In the Earth's atmosphere, the atmospheric pressure  ________.

  1. remains constant with height

  2. increases with height

  3. decreases with height

  4. first increase and then decrease with height
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As we go up the pressure decreases with altitude.

This is because at higher altitudes number of air molecules present are low when compared to those that are present in the lower atmosphere.

Moreover gravitational pull which is responsible for atmospheric pressure is low on the molecules that are away from its surface than those that are closer to it.

Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts the concept of bernoulli's principle air exerts pressure

A column of air 1 sq. cm. in cross-sectional area extending from sea-level to the top of the atmosphere weights approximately ______.

  1. 933 g wt

  2. 1033 g wt

  3. 1136 g wt

  4. 1360 g wt
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
1033 g wt
Air pressure at sea level is about 101 000 Pa. A Pa (pascal), by definition, is a newton per square meter. 
So the weight, force of that column which is 1 square meter in cross-section area is 101000 newtons. 
There are 10000 cm² per m², so we get 
the weight, force of that column 1 square cm in cross-section area is 10.1 newtons ⬅ 
Using F = ma or Weight = mass x acceleration of gravity, 
10.1 newtons corresponds to a mass of 10.1 N / 9.8 = 1.03 kg ⬅ 

that is approximate and does not account for the weight decreasing as you go up in altitude. But most of the air is at low altitudes, so it's close. 
Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts the concept of bernoulli's principle air exerts pressure

The pressure and wind systems are actually the impact of Lithosphere and Hydrosphere on ______.

  1. Homosphere

  2. Heterosphere

  3. Atmosphere

  4. Troposphere
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Atmosphere,

These spheres are closely connected. For example, many birds (biosphere) fly through the air (atmosphere), while water (hydrosphere) often flows through the soil (lithosphere). Interactions also occur among the spheres; for example, a change in the atmosphere can cause a change in the hydrosphere and vice versa.

Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts the concept of bernoulli's principle air exerts pressure

What is the level of mercury at normal atmospheric pressure?

  1. 64 cm

  2. 70 cm

  3. 76 cm

  4. 80 cm
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$76cm$

Atmospheric pressure is expressed in several different systems of units: millimetres (or inches) of mercury, pounds per square inch (psi), dynes per square centimetre, millibars (mb), standard atmospheres, or kilopascals. Standard sea-level pressure, by definition, equals 760 mm (29.92 inches) of mercury, 14.70 pounds per square inch, 1,013.25 × 103 dynes per square centimetre, 1,013.25 millibars, one standard atmosphere, or 101.325 kilopascals. Variations about these values are quite small; for example, the highest and lowest sea-level pressures ever recorded are 32.01 inches (in the middle of Siberia) and 25.90 inches (in a typhoon in the South Pacific). The small variations in pressure that do exist largely determine the wind and storm patterns of Earth.