Class 11 Geography: Water in the Atmosphere — Chapter Question Set

(d) Oxygen
Reprint 2026-27

FUNDAMENTALS OF PHYSICAL GEOGRAPHY90 — This is the textbook-supported choice for the question.

(c) Evaporation — This is the textbook-supported choice for the question.

(d) Saturated air — This is the textbook-supported choice for the question.

(a) Cirrus — This is the textbook-supported choice for the question.

a) air contains water vapour — The textbook states: WATER IN THE ATMOSPHERE Y ou have already learnt that the air contains water vapour.

d) in the weather phenomena — The textbook states: It varies from zero to four per cent by volume of the atmosphere and plays an important role in the weather phenomena.

c) present in the atmosphere in three forms name — The textbook states: Water is present in the atmosphere in three forms namely – gaseous, liquid and solid.

b) derived from water bodies through evaporation — The textbook states: The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration.

a) a continuous exchange of water between the at — The textbook states: Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation.

d) known as humidity — The textbook states: Water vapour present in the air is known as humidity.

c) known as the absolute humidity — The textbook states: The actual amount of the water vapour present in the atmosphere is known as the absolute humidity.

b) the weight of water vapour per unit volume of — The textbook states: It is the weight of water vapour per unit volume of air and is expressed in terms of grams per cubic metre.

a) entirely on its temperature — The textbook states: The ability of the air to hold water vapour depends entirely on its temperature.

d) surface of the earth — The textbook states: The absolute humidity differs from place to place on the surface of the earth.

c) known as the relative humidity — The textbook states: The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity.

b) also affected — The textbook states: With the change of air temperature, the capacity to retain moisture increases or decreases and the relative humidity is also affected.

a) said to be saturated — The textbook states: The air containing moisture to its full capacity at a given temperature is said to be saturated.

d) incapable of holding any additional amount of — The textbook states: It means that the air at the given temperature is incapable of holding any additional amount of moisture at that stage.

c) known as dew point — The textbook states: The temperature at which saturation occurs in a given sample of air is known as dew point.

b) added or withdrawn due to evaporation and con — The textbook states: EVAPORATION AND CONDENSATION The amount of water vapour in the atmosphere is added or withdrawn due to evaporation and condensation respectively.

a) a process by which water is transformed from — The textbook states: Evaporation is a process by which water is transformed from liquid to gaseous state.

d) the amount of heat energy required to convert — The textbook states: Latent heat of vaporisation is the amount of heat energy required to convert a unit mass of a liquid into vapour without a change in temperature.

c) given parcel of air — The textbook states: Increase in tempe rature increases water absorption and retention capacity of the given parcel of air.

b) low — The textbook states: Similarly, if the moisture content is low, air has a potentiality of absorbing and retaining moisture.

a) with the unsaturated layer — The textbook states: Movement of air replaces the saturated layer with the unsaturated layer.

d) the evaporation — The textbook states: Hence, the greater the movement of air, the greater is the evaporation.

c) called condensation — The textbook states: The transformation of water vapour into water is called condensation.

b) cooled — The textbook states: When moist air is cooled, it may reach a level when its capacity to hold water vapour ceases.

a) condenses into liquid form — The textbook states: Then, the excess water vapour condenses into liquid form.

d) as hygroscopic condensation nuclei — The textbook states: In free air, condensation results from cooling around very small particles termed as hygroscopic condensation nuclei.

c) particularly good nuclei because they absorb — The textbook states: Particles of dust, smoke and salt from the ocean are particularly good nuclei because they absorb water.

b) close to the dew point — The textbook states: Condensation also takes place when the moist air comes in contact with some colder object and it may also take place when the temperature is close to the dew point.

a) humidity of the air — The textbook states: Condensation, therefore, depends upon the amount of cooling and the relative humidity of the air.

d) influenced by the volume of air — The textbook states: Condensation is influenced by the volume of air, temperature, pressure and humidity.

c) CHAPTER WATER IN THE — The textbook states: Condensation takes CHAPTER WATER IN THE ATMOSPHERE 87 place: (i) when the temperature of the air is reduced to dew point with its volume remaining constant; (ii) when both the volume and the temperature are reduced; (iv) when moisture is added to the air through evaporation.

b) the decrease in air temperature — The textbook states: However, the most favourable condition for condensation is the decrease in air temperature.

a) frost, fog and clouds — The textbook states: After condensation the water vapour or the moisture in the atmosphere takes one of the following forms — dew, frost, fog and clouds.

d) of temperature and location — The textbook states: Forms of condensation can be classified on the basis of temperature and location.

c) lower than the freezing point as well as high — The textbook states: Condensation takes place when the dew point is lower than the freezing point as well as higher than the freezing point.

b) deposited in the form of water droplets on co — The textbook states: Dew When the moisture is deposited in the form of water droplets on cooler surfaces of solid objects (rather than nuclei in air above the surface) such as stones, grass blades and plant leaves, it is known as dew.

a) clear sky — The textbook states: The ideal conditions for its formation are clear sky, calm air, high relative humidity, and cold and long nights.

d) necessary that the dew point is above the fre — The textbook states: For the formation of dew, it is necessary that the dew point is above the freezing point.

c) freezing point (00C), i.e — The textbook states: Frost Frost forms on cold surfaces when condensation takes place below freezing point (00C), i.e.

b) deposited in the form of minute ice crystals — The textbook states: The excess moisture is deposited in the form of minute ice crystals instead of water droplets.

a) the same as those for the formation of dew — The textbook states: The ideal conditions for the formation of white frost are the same as those for the formation of dew, except that the air temperature must be at or below the freezing point.

d) Mist When — The textbook states: Fog and Mist When the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, condensation takes place within itself on fine dust particles.

c) 1 km — The textbook states: Fog reduces horizontal visibility on earths’ surface to less than 1 km, while mist limits it to between 1 km and 2 km .

b) of fog and mist — The textbook states: In urban and industrial centres smoke provides plenty of nuclei which help the formation of fog and mist.

a) mixed with smoke — The textbook states: Such a condition when fog is mixed with smoke, is described as smog .

d) that mist contains more moisture than the fog — The textbook states: The only difference between the mist and fog is that mist contains more moisture than the fog.

Water is present in the atmosphere in three forms namely – gaseous, liquid and solid. Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation. Types of Rainfall On the basis of origin, rainfall may be classified into three main types – the convectional, orographic or relief and the cyclonic or frontal.

The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity. With the change of air temperature, the capacity to retain moisture increases or decreases and the relative humidity is also affected. Condensation, therefore, depends upon the amount of cooling and the relative humidity of the air.

WATER IN THE ATMOSPHERE Y ou have already learnt that the air contains water vapour. The actual amount of the water vapour present in the atmosphere is known as the absolute humidity. EVAPORATION AND CONDENSATION The amount of water vapour in the atmosphere is added or withdrawn due to evaporation and condensation respectively.

Clouds Cloud is a mass of minute water droplets or tiny crystals of ice formed by the condensation of the water vapour in free air at considerable elevations. As the clouds are formed at some height over the surface of the earth, they take various shapes. Cirrus Cirrus clouds are formed at high altitudes (8,000 - 12,000m).

WATER IN THE ATMOSPHERE Y ou have already learnt that the air contains water vapour.

It varies from zero to four per cent by volume of the atmosphere and plays an important role in the weather phenomena.

Water is present in the atmosphere in three forms namely – gaseous, liquid and solid.

The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration.

Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation.

Water vapour present in the air is known as humidity.

It is expressed quantitatively in different ways.

The actual amount of the water vapour present in the atmosphere is known as the absolute humidity.

It is the weight of water vapour per unit volume of air and is expressed in terms of grams per cubic metre.

The ability of the air to hold water vapour depends entirely on its temperature.

The absolute humidity differs from place to place on the surface of the earth.

The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity.

With the change of air temperature, the capacity to retain moisture increases or decreases and the relative humidity is also affected.

It is greater over the oceans and least over the continents.

The air containing moisture to its full capacity at a given temperature is said to be saturated.

It means that the air at the given temperature is incapable of holding any additional amount of moisture at that stage.

The temperature at which saturation occurs in a given sample of air is known as dew point.

EVAPORATION AND CONDENSATION The amount of water vapour in the atmosphere is added or withdrawn due to evaporation and condensation respectively.

Evaporation is a process by which water is transformed from liquid to gaseous state.

Latent heat of vaporisation is the amount of heat energy required to convert a unit mass of a liquid into vapour without a change in temperature.

Increase in tempe rature increases water absorption and retention capacity of the given parcel of air.

Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation. Precipitation The process of continuous condensation in free air helps the condensed particles to grow in size. So after the condensation of water vapour , the r elease of moistur e is known as precipitation. The precipitation in the form of water is called rainfall, when the temperature is lower than the 00C, precipitation takes place in the form of fine flakes of snow and is called snowfall. Besides rain and snow, other forms of precipitation are sleet and hail, though the latter are limited in occurrence and are sporadic in both time and space. World Distribution of Rainfall Different places on the earth’s surface receive different amounts of rainfall in a year and that too in different seasons. On the basis of the total amount of annual precipitation, major precipitation regimes of the world are identified as follows.

Condensation also takes place when the moist air comes in contact with some colder object and it may also take place when the temperature is close to the dew point. Condensation takes CHAPTER WATER IN THE ATMOSPHERE 87 place: (i) when the temperature of the air is reduced to dew point with its volume remaining constant; (ii) when both the volume and the temperature are reduced; (iv) when moisture is added to the air through evaporation. After condensation the water vapour or the moisture in the atmosphere takes one of the following forms — dew, frost, fog and clouds. Forms of condensation can be classified on the basis of temperature and location. Condensation takes place when the dew point is lower than the freezing point as well as higher than the freezing point. Frost Frost forms on cold surfaces when condensation takes place below freezing point (00C), i.e. The ideal conditions for the formation of white frost are the same as those for the formation of dew, except that the air temperature must be at or below the freezing point.

WATER IN THE ATMOSPHERE Y ou have already learnt that the air contains water vapour. WATER IN THE ATMOSPHERE Y ou have already learnt that the air contains water vapour. It varies from zero to four per cent by volume of the atmosphere and plays an important role in the weather phenomena. Water is present in the atmosphere in three forms namely – gaseous, liquid and solid.

It varies from zero to four per cent by volume of the atmosphere and plays an important role in the weather phenomena. WATER IN THE ATMOSPHERE Y ou have already learnt that the air contains water vapour. It varies from zero to four per cent by volume of the atmosphere and plays an important role in the weather phenomena. Water is present in the atmosphere in three forms namely – gaseous, liquid and solid. The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration.

Water is present in the atmosphere in three forms namely – gaseous, liquid and solid. It varies from zero to four per cent by volume of the atmosphere and plays an important role in the weather phenomena. Water is present in the atmosphere in three forms namely – gaseous, liquid and solid. The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration. Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation.

The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration. Water is present in the atmosphere in three forms namely – gaseous, liquid and solid. The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration. Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation. Water vapour present in the air is known as humidity.

Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation. The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration. Thus, there is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation. Water vapour present in the air is known as humidity. It is expressed quantitatively in different ways.