Tag: pressure belts

Questions Related to pressure belts

The weight of humid air is _______ to than dry air.

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

  1. more

  2. less

  3. equal

  4. equivalent

Show answer
Correct Option: B
Explanation:

The weight of humid air is less to than dry air.


Our air is primarily composed of nitrogen and oxygen, but it always has some water molecules.

The weight of an individual atom is represented by its atomic weight. The (rounded) atomic weight of hydrogen (H) is 1, oxygen (O) is 16, nitrogen (N) is 14, and carbon (C) is 12.

The weight of a molecule is determined by summing the atomic weights of its atoms. A water molecule (H2O) has a molecular weight of 18 (1 + 1 + 16). Free nitrogen (N2) has a molecular weight of 28, and an oxygen molecule (O2) has an atomic weight of 32. Therefore, a water molecule is lighter than either a nitrogen or an oxygen molecule.

Any fixed volume of a gas at constant pressure and temperature has the same number of molecules. It does not matter what the gas is — the same number of molecules will exist in that volume.

To make a given volume of air moister, we need to add water vapor molecules to the volume. To add water molecules to the volume, we must remove other molecules to conserve the total number of molecules in the volume.

Dry air consists mostly of nitrogen and oxygen molecules, which weigh more than water molecules. This means that when a given volume of air is made more moist by adding water molecules, heavier molecules are replaced with lighter molecules. Therefore, moist air is lighter than dry air if both are at the same temperature and pressure

The speed and the direction of wind are based on which of the following? 

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

  1. Pressure gradient force

  2. Coriolis force

  3. Friction

  4. All of the above

Show answer
Correct Option: D
Explanation:

Pressure gradient force,

winds balanced by the Coriolis and Pressure Gradient forces. An air parcel initially at rest will move from high pressure to low pressure because of the pressure gradient force (PGF). ... As the wind gains speed, the deflection increases until the Coriolis force equals the pressure gradient force.
Coriolis force,
The Coriolis effect influences wind by deflecting its path to the right in the Northern Hemisphere. The sequence of weather satellite images shows that the actual wind direction is from the southwest. The satellite images show atmospheric motion over the northern Pacific Ocean for a 36-hour period.
Friction,
 Winds affected by friction. Geostrophic wind blows parallel to the isobars because the Coriolis force and pressure gradient force are in balance. ... As we move higher, surface features affect the wind less until the wind is indeed geostrophic.

The atmospheric pressure decreases at the rate of ______________.

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. 1 millibar/altitude of 10 meters

  2. 1 millibar/altitude of 15 meters

  3. 1 millibar/altitude of 18 meters

  4. 1 millibar/altitude of 20 meters

Show answer
Correct Option: A
Explanation:

Near Earth's surface the pressure decreases with height at a rate of about 1 millibars for every 10 metres. However, over cold air the decrease in pressure can be much steeper because its density is greater than warmer air.

When the temperature increases atmospheric pressure _________.

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. increases

  2. decreases

  3. remains same

  4. became zero

Show answer
Correct Option: B
Explanation:

There exists a negative relation between pressure and temperature. When temperature increases pressure will fall and vice versa. That is why, pressure increases from equatorial region towards the polar region.

Assertion (A) : Westerlies are stronger in the northen Hemisphere than in the southern Hemisphere
Reason (R) : The nothern Hemisphere has more land area than the southern Hemisphere.

geography atmosphere and climate pressure belts elements of weather and climate :rainfall and air pressure monsoon phenomena and its mechanism

  1. Both 'A' and 'R' are true and 'R' is the correct explanation of 'A'.

  2. Both 'A' and 'R' are true and 'R' is not the correct explanation of 'A'.

  3. 'A' is true but 'R'n is false.

  4. 'A' is false but 'R' is true

Show answer
Correct Option: D
Explanation:

The westerlies are the prevailing winds in the middle latitudes between $35^{\circ}$ and $65^{\circ}$ latitude blowing from the west to east. The westerlies are strong especially in the southern hemisphere where there is less land in middle latitudes to cause flow pattern to amplify. The strongest westerly winds southern hemisphere is Roaring Forties which blows between $40^{\circ}$ and $50^{\circ}$ latitudes.

The horizontal movement of air is called ________.

geography winds pressure belts elements of weather and climate :rainfall and air pressure monsoon phenomena and its mechanism

  1. Wind

  2. Storm

  3. Cyclone

  4. Both A and C

Show answer
Correct Option: A
Explanation:

Wind is defined as the perceptible natural movement of the air, especially in the form of a current of air blowing from a particular direction whereas breeze is the gentle wind.

Why do coastal areas experience less contrasts in temparature conditions?

geography winds pressure belts elements of weather and climate :rainfall and air pressure monsoon phenomena and its mechanism

  1. Due to moderating effect of the seas

  2. Due to land mass

  3. Due to heat conditions

  4. Due to rotation of the earth

Show answer
Correct Option: A
Explanation:

Coastal areas experience less contrasts in temperature conditions due to moderating effect of the seas.  The large water bodies helps in moderating temperature. Water has a higher heat capacity than soil and rock, so the ocean takes much longer to heat and to cool than the land.

Tropical cyclones cause rains on the _______.

geography atmosphere and climate pressure belts elements of weather and climate :rainfall and air pressure monsoon phenomena and its mechanism

  1. Malabar coast

  2. Coromandel coast

  3. Konkan coast

  4. Saurashtra coast

Show answer
Correct Option: B
Explanation:

Tropical cyclones causes rains on the Coromandel coast. Devastating cyclones originate in the Indian ocean especially in the Bay of  Bengal. The highest frequency of the cyclones is in the month of October and the first half of November. These cyclones are accompanied by strong winds, dense cloud, thundering and heavy rain. 

An instrument which measures the force and velocity of winds is called ______________.

geography winds pressure belts elements of weather and climate :rainfall and air pressure monsoon phenomena and its mechanism

  1. Barometer

  2. Anemometer

  3. Thermometer

  4. Hygrometer

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Correct Option: D

The instrument used for measuring air pressure is called __________________.

geography atmosphere and climate pressure belts elements of weather and climate :rainfall and air pressure monsoon phenomena and its mechanism

  1. Hydrometer

  2. Anemometer

  3. Barometer

  4. Thermometer

Show answer
Correct Option: C
Explanation:
  • The barometer is used for measuring atmospheric pressure, hence option C is correct.
  • Thermometer, is used to measure the temperature of human body.
  • Anemometer is used to measure wind speed and direction.
  • A hydrometer is used to measure the relative density of liquids.