Important Questions and Answers for Class 11 Geography Chapter 10 Water in the Atmosphere 2025-26

Q1. Which of the following processes is responsible for transforming liquid water into vapour in the atmosphere?

• (a) Condensation
• (b) Transpiration
• (c) Evaporation
• (d) Precipitation

Answer: (c) Evaporation. 

It is the conversion of liquid water to vapour by heat, adding moisture to the atmosphere.

Q2. Which type of cloud is found at the highest altitude in the sky?

• (a) Cirrus
• (b) Stratus
• (c) Nimbus
• (d) Cumulus

Answer: (a) Cirrus. 

Cirrus clouds form at 8,000–12,000m and are the highest in the sky.

Q3. The term used for the temperature at which air becomes saturated and condensation begins is:

• (a) Dew point
• (b) Frost point
• (c) Boiling point
• (d) Freezing point

Answer: (a) Dew point. 

Dew point is the temperature at which air is fully saturated with moisture and condensation occurs.

Q4. Sleet is best described as:

• (a) Water drops
• (b) Snowflakes
• (c) Frozen raindrops or refrozen melted snow-water
• (d) Dust particles

Answer: (c) Frozen raindrops or refrozen melted snow-water. 

Sleet forms when rain encounters cold air and solidifies.

2. Very Short Answer (VSA).

Q1. Define humidity in the context of the atmosphere.

Answer: Humidity is the amount of water vapour present in the air. It is an important factor affecting weather and can be measured as absolute or relative humidity.

Q2. What is meant by the 'dew point'?

Answer: Dew point is the temperature at which air becomes fully saturated with moisture, causing water vapour to start condensing into liquid.

Q3. State one major difference between fog and mist.

Answer: Mist contains more moisture than fog; mist droplets are larger and form a thicker layer, reducing visibility less than fog.

Q4. Name any two forms of condensation found close to the ground.

Answer: Dew and frost are two forms of condensation commonly occurring close to the ground on cool surfaces.

3. Short Answer Questions.

Q1. Explain relative humidity and its significance.

Answer: Relative humidity is the percentage of moisture present in the air compared to its maximum capacity at a specific temperature. It indicates how close the air is to being saturated and helps predict the likelihood of rainfall or dew formation.

Q2. Describe how orographic (relief) rainfall occurs.

Answer: Orographic rainfall happens when moist air is forced to ascend over a mountain barrier. As the air rises, it cools and condenses to form clouds, causing heavy rainfall on the windward side and drier conditions on the leeward side, known as the rain-shadow area.

Q3. Briefly explain the process of condensation in the atmosphere.

Answer: Condensation occurs when air cools and can't hold all its moisture, causing excess water vapour to turn into liquid. This typically happens around dust or smoke particles that act as condensation nuclei, leading to dew, fog, or cloud formation.

Q4. What are the main characteristics of nimbus clouds?

Answer: Nimbus clouds are dense, dark gray, and often shapeless. They form at low to middle altitudes, are thick enough to block sunlight, and are mainly associated with continuous rain or precipitation.

4. Long Answer Questions.

Q1. Discuss the major features of the world distribution of rainfall.

Answer: The world distribution of rainfall is uneven, influenced by latitude, proximity to oceans, winds, and topography. Rainfall decreases from the equator to the poles. Coastal and mountain windward areas get heavy rainfall, while interiors and rain-shadow regions are drier. Seasonal patterns vary greatly, and some regions receive rain throughout the year, while others have dry or wet seasons.

1. Equatorial and coastal areas get >200 cm annually.
2. Interiors and rain-shadow zones receive <50 cm yearly.
3. Distribution is affected by mountains and wind patterns.

Q2. Explain various forms of condensation and describe the process for dew and frost formation.

Answer: Condensation can occur as dew, frost, fog, or clouds, depending on temperature and surface conditions. Dew forms as water droplets on cool surfaces when air temperature drops to the dew point above freezing. Frost forms when condensation occurs below freezing, creating fine ice crystals on surfaces. Both processes require clear skies, calm air, and high humidity.

1. Dew: Air cools, dew point above 0°C, drops form on cool surfaces.
2. Frost: Dew point at or below 0°C, water vapour freezes as crystals.

Q3. Analyse how temperature influences the capacity of air to hold water vapour.

Answer: Temperature directly affects the air's ability to hold water vapour. As temperature rises, air can contain more vapour; when it cools, capacity falls, leading to condensation if full saturation is reached. Thus, sudden temperature changes play a key role in humidity, rainfall, and condensation phenomena.

5. Assertion–Reason type questions.

Assertion (A): Orographic rainfall occurs mainly on the windward side of mountains.
Reason (R): The air on the leeward side of mountains loses moisture and becomes dry.

• (a) A and R are true, and R is the correct explanation of A
• (b) A and R are true, but R is not the correct explanation of A
• (c) A is true, but R is false
• (d) A is false, but R is true

Answer: (a) A and R are true, and R correctly explains that air gets dry after losing moisture on the windward side.

Assertion (A): Condensation is more likely to occur during clear, calm nights.
Reason (R): Clear, calm nights reduce heat loss from the Earth's surface.

• (a) A and R are true, and R is the correct explanation of A
• (b) A and R are true, but R is not the correct explanation of A
• (c) A is true, but R is false
• (d) A is false, but R is true

Answer: (c) A is true, but R is false. In fact, clear, calm nights enhance heat loss, promoting condensation.

3. Fill in the Blanks Questions.

Q1. The process where water vapour changes directly into ice crystals without becoming liquid first is called ______.

Answer: Sublimation. 

This process typically contributes to the formation of frost on very cold surfaces, where water vapour turns into solid ice directly.

Q2. The capacity of air to hold water vapour depends entirely on its ______.

Answer: Temperature. 

Warmer air can hold more water vapour; as temperature increases, the air’s moisture-holding ability also increases, influencing weather outcomes.

Q3. The area on the leeward side of a mountain receiving less rainfall is called the ______.

Answer: Rain-shadow area. This dry zone occurs because air, after releasing moisture on the windward side, descends and warms, reducing chances for rain.

Benefits of Understanding Water in the Atmosphere for Students

Learning about class 11 geography chapter 10 important questions Water in the Atmosphere helps students recognize key weather patterns. Grasping processes like humidity, precipitation and cloud types builds a strong base for further studies in world geography and climate.

Reviewing these important NCERT topics prepares you for MCQs and long answers on geography chapter 11 Water in the Atmosphere. You’ll develop clarity on rainfall types, condensation forms, and seasonal rainfall patterns relevant for both school and higher level studies.