Tag: variations in atmospheric pressure

Questions Related to variations in atmospheric pressure

When a vehicle travels very fast, a region of ______ is created temporarily just behind it.

chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

  1. High pressure

  2. Low pressure

  3. High density

  4. Cyclone

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Correct Option: B
Explanation:
When a vehicle moves very fast, a low pressure is produced temporarily and the wind nearby rushes in to fill its place.

Which of the following principle shows that if you increase air speed its pressure will decrease?

chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

  1. Darwin principle

  2. Einstein principle

  3. Bohr principle

  4. Bernoulli's principle

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Correct Option: D
Explanation:
According to Bernoulli's principle, Fast moving air equals low air pressure while slow moving air equals high air pressure.
 Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure. The same is applicable in case of gases also.

Increase in air speed is associated with ______________ .

chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

  1. increasein air pressure

  2. decrease in air pressure

  3. increase in air temperature

  4. decrease in air temperature

Show answer
Correct Option: B
Explanation:
The increased wind speed is accompanied by a reduced air pressure.

A piece of paper is kept on the table.  You have to lift it from the table by blowing high-speed air over it. In which direction will you blow the air?

chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

  1. Sideways

  2. In the upward direction

  3. In the downward direction

  4. In the upward direction below the table

Show answer
Correct Option: A
Explanation:
In order to lift the paper up from the table we need to blow air in sideways.

Two pieces of papers are held parallel. Air is blown with a high speed in between them. Which of the following phenomena will be observed?

chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

  1. The papers will move away from each other.

  2. The papers will move towards each other.

  3. The papers will stay at their position.

  4. The papers will catch fire due to increase in air temperature.

Show answer
Correct Option: B
Explanation:
It seems amazing that the two sheets of paper move closer together, the pressure is reduced where the air is moving quickly. This is called the Bernoulli principle. 

Doldrums are _________.

geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts

  1. regions of the Atlantic and Pacific oceans

  2. regions of the planets 

  3. regions of the earth

  4. none of the above

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Correct Option: A
Explanation:

Doldrums are regions of the Atlantic and Pacific oceans that have little if any wind. Doldrums are caused by solar radiation from the sun, as sunlight beams down directly on area around the equator. This heating causes the air to warm and rise straight up rather than blow horizontally. The result is little or no wind, sometimes for weeks on end. The Doldrums are located a little north of the equator, but the effects can be felt from 5 degrees north of the equator to 5 degrees south of it. This was a particular problem for sailors in the past when they depended on the winds to propel their ships. It was a problem that could be potentially deadly.

Altimeter is a device to measure  ____________.

geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts

  1. Temperature

  2. Height

  3. Altitude

  4. Rainfall

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Correct Option: B
Explanation:

Altimeter is an instrument that measures the height of the land surface or any object such as an airplane. The most common types of altimeters are barometric. They determine altitude by measuring air pressure. As altitude increases, air pressure decreases. This is because the density of air is lower at high altitudes. Altimeters are important navigation instruments for aircraft and spacecraft pilots who monitor their height above the Earth’s surface. Skydivers and mountaineers also use altimeters to pinpoint their location in the sky or on the ground.

In normal conditions, atmospheric pressure varies with__________ 

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

  1. Height 

  2. Altitude

  3. Rainfall

  4. Temperature

Show answer
Correct Option: A,B
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.

The line joining places of equal atmospheric pressure is called ______________.

geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts

  1. Contour

  2. Isohyet

  3. Isotherm

  4. Isobar

Show answer
Correct Option: D
Explanation:

Isobars are imaginary lines joining the places having equal values of pressure. The horizontal distribution of pressure is shown by isobars. For convenience all the local level pressures are converted to sea level. Closely spaced isobars indicate strong pressure gradient and widely spaced isobars indicate weak pressure gradient.

Which one of the following is used for measuring the speed of wind ?

geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts

  1. Hygrometer

  2. Barometer

  3. Anemometer

  4. Thermometer

Show answer
Correct Option: C
Explanation:

Anemometer is a device which is used for measuring the speed of wind in the atmosphere. It also measures wind pressure. Anemometers are important tools for meteorologists, who study weather patterns. They are also important to the work of physicists, who study the way air moves. Anemometer has three or four cups attached to horizontal arms. The arms are attached to a vertical rod. As the wind blows, the cups rotate, making the rod spin. The stronger the wind blows, the faster the rod spins. The anemometer counts the number of rotations, or turns, which is used to calculate wind speed.