Question Bank — Atmosphere and Climate

NCERT Class 9 Social Science · Chapter 3 · CBSE Board Pattern

Class 9 Social Science Chapter 3 Question Bank CBSE Board Pattern

QUESTION BANK

Class 09 – Social Science

Chapter: Atmosphere and Climate

Section A — MCQs (1 mark each)

1. Which gas constitutes the largest percentage of the Earth’s atmosphere?
(a) Oxygen (b) Nitrogen (c) Carbon dioxide (d) Argon

2. In which layer of the atmosphere do almost all weather phenomena occur?
(a) Stratosphere (b) Mesosphere (c) Troposphere (d) Thermosphere

3. The ozone layer is found in which layer of the atmosphere?
(a) Troposphere (b) Stratosphere (c) Mesosphere (d) Exosphere

4. The term ‘monsoon’ is derived from the Arabic word:
(a) Mausim (b) Monsoon (c) Nakshatra (d) Ritu

5. Which of the following is not an element of weather and climate?
(a) Temperature (b) Insolation (c) Latitude (d) Humidity

6. Air moves from:
(a) Low-pressure area to high-pressure area (b) High-pressure area to low-pressure area (c) Equator to poles only (d) Land to sea only at night

7. The south-west monsoon brings rainfall to most parts of India during:
(a) October–December (b) June–September (c) March–May (d) January–February

8. Which layer of the atmosphere helps in radio transmission by reflecting radio waves?
(a) Troposphere (b) Stratosphere (c) Ionosphere (part of thermosphere) (d) Exosphere

9. Assertion (A): Temperature decreases with increasing altitude in the troposphere.
Reason (R): The troposphere contains most of the water vapour and dust particles.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both 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.

10. Assertion (A): The north-east monsoon brings rainfall to the eastern coast of India, especially Tamil Nadu.
Reason (R): The north-east monsoon winds pick up moisture while passing over the Bay of Bengal.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both 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.

Section B — Very Short Answer (2 marks each)

1. Define atmosphere. Name the two most abundant gases in it.
2. What is the difference between weather and climate?
3. Define insolation. How does it affect temperature distribution on Earth?
4. What is humidity? Why do we feel uncomfortable on a humid day?
5. Distinguish between land breeze and sea breeze.
6. What is meant by carbon footprint?

Section C — Short Answer (3 marks each)

1. Describe the composition of the atmosphere with the help of a pie diagram description.
2. Explain why aeroplanes prefer to fly in the stratosphere.
3. Differentiate between the south-west monsoon and the north-east monsoon.
4. How do temperature and altitude affect atmospheric pressure? Give reasons.
5. Why is monsoon rainfall important for the Indian economy? Give any three reasons.

Section D — Long Answer (5 marks each)

1. Describe the structure of the atmosphere with the help of a labelled diagram. Explain the importance of any three layers.
2. Explain the mechanism of the south-west monsoon in India. How does it influence agriculture and the daily life of the people?
3. What is climate change? Discuss its causes and consequences. Suggest any three ways to reduce our carbon footprint.

Section E — Source-Based Questions (4 marks each)

Source 1

“The troposphere is the most important layer of the atmosphere, with an average height of about 12 kilometres. In this layer, temperature decreases with increasing altitude. The air we breathe exists here, along with most of the water vapour and clouds. Nearly all the weather phenomena, such as rainfall, fog, and hail, occur in this layer.”

Questions:

(a) Name the layer described in the source. (1)
(b) What happens to temperature with increasing altitude in this layer? (1)
(c) Why is this layer called the most important layer? Give two reasons. (2)
(d) Name the transition zone that separates this layer from the stratosphere. (1)

Source 2

“Monsoon winds are seasonal winds. They can be categorised into the south-west and the north-east monsoon. The south-west monsoon… is mainly caused by the unequal heating of land and the sea. During summer, the landmass of India heats up faster than the surrounding oceans. This creates a low-pressure area over the Indian subcontinent…”

Questions:

(a) What causes the reversal of monsoon winds? (1)
(b) Why does a low-pressure area develop over India in summer? (1)
(c) Which monsoon is also called the summer monsoon and why? (1)
(d) Mention one region that receives rainfall from the north-east monsoon. (1)

▶ Answer Key Attempt all questions first,
then tap to reveal

Section A

  1. (b) 2. (c) 3. (b) 4. (a) 5. (c) 6. (b) 7. (b) 8. (c)
  2. (b) 10. (a)

Section B

  1. Blanket of air surrounding the Earth (1); Nitrogen (78%) and Oxygen (21%) (1)
  2. Weather: hour-to-hour/day-to-day conditions (1); Climate: average weather over 30+ years (1)
  3. Incoming solar energy intercepted by Earth (1); decreases from equator to poles (1)
  4. Presence of water vapour in air (1); sweat evaporates slowly (1)
  5. Land breeze: night, land to sea (1); Sea breeze: day, sea to land (1)
  6. Total greenhouse gases released due to human activities (2)

Section C

  1. Nitrogen 78%, Oxygen 21%, Argon 0.93%, CO₂ 0.04%, others (any three points, 1 mark each)
  2. Free of weather disturbances/clouds; suitable for flying (any three points)
  3. Any three valid differences (direction, season, moisture)
  4. Pressure falls with altitude; high temperature → low pressure; low temperature → high pressure (any three)
  5. Agriculture depends on it; water supply; affects employment/festivals (any three)

Section D

  1. Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere with characteristics (any three layers with importance)
  2. Unequal heating → low pressure over land → moist winds from ocean (mechanism + impact on agriculture & life)
  3. Human activities (fossil fuels, deforestation) → greenhouse gases → global warming, floods, droughts + three reduction measures

Section E

Source 1

(a) Troposphere (supported by first line)
(b) Decreases with altitude (supported by second sentence)
(c) Contains air we breathe; most water vapour & clouds; all weather phenomena (any two)
(d) Tropopause

Source 2

(a) Unequal heating of land and sea (supported by source)
(b) Land heats faster than ocean in summer (supported by source)
(c) South-west monsoon (June–September)
(d) Tamil Nadu / Andhra Pradesh / parts of Karnataka (any one)

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All questions are answerable from the NCERT chapter text. Reviewed by GFIS faculty.