CHAPTER 3: ATMOSPHERE AND CLIMATE
50 MULTIPLE CHOICE QUESTIONS (MCQs)
Q1. What is the atmosphere?
(A) A layer of solid rocks surrounding Earth
(B) A blanket of air surrounding Earth
(C) A layer of water surrounding Earth
(D) A layer of soil covering Earth
Answer: (B) A blanket of air surrounding Earth
Q2. Which force holds the atmosphere around the Earth?
(A) Magnetic force
(B) Frictional force
(C) Gravity
(D) Muscular force
Answer: (C) Gravity
Q3. Which two gases are the most abundant in the Earth’s atmosphere?
(A) Nitrogen and oxygen
(B) Oxygen and carbon dioxide
(C) Nitrogen and hydrogen
(D) Argon and helium
Answer: (A) Nitrogen and oxygen
Q4. Approximately what percentage of the atmosphere is nitrogen?
(A) 21%
(B) 0.04%
(C) 0.93%
(D) 78%
Answer: (D) 78%
Q5. Approximately what percentage of the atmosphere is oxygen?
(A) 78%
(B) 21%
(C) 0.93%
(D) 0.04%
Answer: (B) 21%
Q6. What is the approximate percentage of carbon dioxide in the atmosphere, according to the textbook diagram?
(A) 21%
(B) 0.93%
(C) 0.04%
(D) 78%
Answer: (C) 0.04%
Q7. Which atmospheric component plays an important role in cloud formation and precipitation?
(A) Water vapour
(B) Nitrogen
(C) Argon
(D) Helium
Answer: (A) Water vapour
Q8. On what basis are the major layers of the atmosphere defined?
(A) Soil composition and rainfall
(B) Ocean currents and tides
(C) Distance from the equator only
(D) Changes in temperature and density with altitude
Answer: (D) Changes in temperature and density with altitude
Q9. Which is the lowest layer of the atmosphere?
(A) Stratosphere
(B) Troposphere
(C) Mesosphere
(D) Thermosphere
Answer: (B) Troposphere
Q10. What is the approximate average height of the troposphere?
(A) 50 kilometres
(B) 80 kilometres
(C) 12 kilometres
(D) 700 kilometres
Answer: (C) 12 kilometres
Q11. In which layer do almost all weather phenomena, such as rainfall, fog and hail, occur?
(A) Troposphere
(B) Mesosphere
(C) Exosphere
(D) Thermosphere
Answer: (A) Troposphere
Q12. Which layer of the atmosphere contains the ozone layer?
(A) Troposphere
(B) Mesosphere
(C) Exosphere
(D) Stratosphere
Answer: (D) Stratosphere
Q13. Up to approximately what height does the stratosphere extend?
(A) 12 kilometres
(B) 50 kilometres
(C) 80 kilometres
(D) 700 kilometres
Answer: (B) 50 kilometres
Q14. Why is the stratosphere suitable for flying aeroplanes?
(A) It contains the highest amount of water vapour.
(B) It is the layer where most rainfall occurs.
(C) It is relatively free from clouds and weather disturbances.
(D) It is the lowest layer of the atmosphere.
Answer: (C) It is relatively free from clouds and weather disturbances.
Q15. In which atmospheric layer do most meteorites entering from space burn up?
(A) Mesosphere
(B) Troposphere
(C) Stratosphere
(D) Exosphere
Answer: (A) Mesosphere
Q16. Up to approximately what height does the mesosphere extend?
(A) 12 kilometres
(B) 50 kilometres
(C) 700 kilometres
(D) 80 kilometres
Answer: (D) 80 kilometres
Q17. In which layer does temperature rise rapidly with increasing altitude because gases absorb X-rays and short-wave ultraviolet radiation?
(A) Troposphere
(B) Thermosphere
(C) Mesosphere
(D) Stratosphere
Answer: (B) Thermosphere
Q18. The ionosphere is a part of which atmospheric layer?
(A) Troposphere
(B) Stratosphere
(C) Thermosphere
(D) Exosphere
Answer: (C) Thermosphere
Q19. In which atmospheric layer do auroras occur?
(A) Thermosphere
(B) Troposphere
(C) Stratosphere
(D) Mesosphere
Answer: (A) Thermosphere
Q20. Which is the uppermost layer of the atmosphere?
(A) Mesosphere
(B) Troposphere
(C) Thermosphere
(D) Exosphere
Answer: (D) Exosphere
Q21. What is meant by weather?
(A) Average atmospheric conditions over thirty years
(B) Hour-to-hour and day-to-day atmospheric conditions
(C) The movement of tectonic plates
(D) The permanent condition of the Earth’s surface
Answer: (B) Hour-to-hour and day-to-day atmospheric conditions
Q22. What does climate refer to?
(A) Weather conditions lasting only a few hours
(B) Temperature recorded on a single day
(C) Average weather conditions over a long period, usually thirty years or more
(D) The direction of wind on a particular afternoon
Answer: (C) Average weather conditions over a long period, usually thirty years or more
Q23. Which of the following is an element of weather and climate?
(A) Atmospheric pressure
(B) Soil texture
(C) Rock structure
(D) Plate movement
Answer: (A) Atmospheric pressure
Q24. What is insolation?
(A) The pressure exerted by air
(B) The movement of air from high to low pressure
(C) The amount of water vapour in the air
(D) Incoming solar energy intercepted by the Earth
Answer: (D) Incoming solar energy intercepted by the Earth
Q25. How does temperature generally change from the equator towards the poles?
(A) It increases continuously.
(B) It generally decreases.
(C) It remains exactly the same.
(D) It becomes unrelated to sunlight.
Answer: (B) It generally decreases.
Q26. What is humidity?
(A) The amount of dust on the Earth’s surface
(B) The force exerted by the atmosphere
(C) The presence of water vapour in the air
(D) The movement of air towards the sea
Answer: (C) The presence of water vapour in the air
Q27. Which of the following is a form of precipitation?
(A) Hail
(B) Dust
(C) Smoke
(D) Oxygen
Answer: (A) Hail
Q28. What is atmospheric pressure?
(A) The pressure exerted by ocean waves
(B) The force exerted by sunlight alone
(C) The pressure exerted by rocks underground
(D) The pressure exerted by the weight of air on the Earth’s surface
Answer: (D) The pressure exerted by the weight of air on the Earth’s surface
Q29. How does atmospheric pressure change with increasing altitude?
(A) It always increases.
(B) It decreases.
(C) It remains constant.
(D) It becomes equal to ocean pressure.
Answer: (B) It decreases.
Q30. In which direction does air generally move due to differences in atmospheric pressure?
(A) From low pressure to high pressure
(B) Only from north to south
(C) From high pressure to low pressure
(D) Only from land to sea
Answer: (C) From high pressure to low pressure
Q31. What is wind?
(A) The movement of air from a high-pressure area to a low-pressure area
(B) The movement of ocean water towards the coast
(C) The downward movement of rainwater
(D) The rising of temperature near the equator
Answer: (A) The movement of air from a high-pressure area to a low-pressure area
Q32. What is a wind blowing from the west called?
(A) Easterly
(B) Northerly
(C) Southerly
(D) Westerly
Answer: (D) Westerly
Q33. When does a sea breeze generally blow?
(A) From land to sea during the day
(B) From sea to land during the day
(C) From land to sea throughout the year only
(D) From sea to land only during winter nights
Answer: (B) From sea to land during the day
Q34. Why does a sea breeze develop during the day?
(A) The sea heats faster than the land.
(B) The land and sea always have equal temperatures.
(C) The land heats faster than the sea, creating relatively low pressure over land.
(D) Atmospheric pressure becomes equal everywhere.
Answer: (C) The land heats faster than the sea, creating relatively low pressure over land.
Q35. In which direction does a land breeze generally blow at night?
(A) From land to sea
(B) From sea to land
(C) From the equator to the poles only
(D) From mountains towards the equator only
Answer: (A) From land to sea
Q36. Which organisation recognises four distinct main seasons in India in the textbook?
(A) World Health Organization
(B) United Nations Environment Programme
(C) Geological Survey of India
(D) India Meteorological Department
Answer: (D) India Meteorological Department
Q37. Which of the following is NOT one of the four main seasons recognised by the IMD in India?
(A) Winter
(B) Spring
(C) Monsoon
(D) Post-monsoon
Answer: (B) Spring
Q38. Which months generally cover the summer or pre-monsoon season in India?
(A) October to December
(B) December to early April
(C) April to June, or up to July in north-western India
(D) June to September only
Answer: (C) April to June, or up to July in north-western India
Q39. During which period does the monsoon or rainy season generally occur in India?
(A) June to September
(B) December to February
(C) January to March
(D) October to December only
Answer: (A) June to September
Q40. What does the term “monsoon” refer to?
(A) A permanent wind blowing in one direction
(B) A sudden fall in atmospheric pressure
(C) A type of precipitation made only of snow
(D) The seasonal reversal in wind direction during a year
Answer: (D) The seasonal reversal in wind direction during a year
Q41. Which word is the origin of the term “monsoon” according to the textbook?
(A) Sanskrit word meaning rain
(B) Arabic word “mausim”, meaning season
(C) Latin word meaning wind
(D) Greek word meaning cloud
Answer: (B) Arabic word “mausim”, meaning season
Q42. What is the main cause of the south-west monsoon?
(A) Equal heating of land and sea
(B) The Earth’s rotation alone
(C) Unequal heating of land and sea
(D) The absence of atmospheric pressure
Answer: (C) Unequal heating of land and sea
Q43. During the south-west monsoon, which condition develops over the Indian subcontinent in summer?
(A) A low-pressure area
(B) A permanent high-pressure area
(C) No atmospheric pressure
(D) Equal pressure everywhere
Answer: (A) A low-pressure area
Q44. From which direction do the south-west monsoon winds bring moist air towards India?
(A) From the Himalayas towards the Indian Ocean
(B) From the land towards the sea
(C) From the north-east towards the land only
(D) From the surrounding seas and oceans towards the land
Answer: (D) From the surrounding seas and oceans towards the land
Q45. Which region of India receives important rainfall from the north-east monsoon?
(A) The north-western desert region only
(B) The south-eastern region, including Tamil Nadu
(C) The entire Himalayan region only
(D) The Thar Desert alone
Answer: (B) The south-eastern region, including Tamil Nadu
Q46. Which of the following is a major human cause of climate change mentioned in the textbook?
(A) The formation of clouds
(B) The natural movement of ocean waves
(C) Burning fossil fuels and deforestation
(D) The daily rising and setting of the Sun
Answer: (C) Burning fossil fuels and deforestation
Q47. Which of the following is a greenhouse gas mentioned in the climate change section?
(A) Methane
(B) Neon only
(C) Argon only
(D) Helium only
Answer: (A) Methane
Q48. What is a carbon footprint?
(A) The amount of carbon stored only in rocks
(B) The weight of soil beneath a tree
(C) The quantity of oxygen produced by a forest
(D) The total amount of greenhouse gases released as a result of human activities
Answer: (D) The total amount of greenhouse gases released as a result of human activities
Q49. Which of the following can help reduce our carbon footprint?
(A) Leaving electrical appliances switched on when not in use
(B) Saving energy and using renewable energy sources
(C) Increasing the use of single-use plastics
(D) Wasting water regularly
Answer: (B) Saving energy and using renewable energy sources
Q50. Which combination of factors contributed to the severe Punjab floods discussed in the textbook’s 2025 case study?
(A) Very low rainfall and falling river levels
(B) Only a shortage of groundwater
(C) Heavy monsoon rainfall, swollen rivers and human-made factors such as weak embankments
(D) Only snowfall in the Himalayan region
Answer: (C) Heavy monsoon rainfall, swollen rivers and human-made factors such as weak embankments
Class 9 Social Science MCQ Chapter 3
CHAPTER 3: ATMOSPHERE AND CLIMATE
ASSERTION–REASON QUESTIONS
Directions: Choose the correct option for each question.
(A) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.
Q1. Assertion (A): Nitrogen and oxygen are the two most abundant gases in the Earth’s atmosphere.
Reason (R): Nitrogen makes up approximately 78% and oxygen approximately 21% of the atmosphere.
Answer: (A)
Q2. Assertion (A): Almost all weather phenomena occur in the stratosphere.
Reason (R): The troposphere contains most of the water vapour and clouds.
Answer: (D)
Q3. Assertion (A): The ozone layer is an important feature of the stratosphere.
Reason (R): The ozone layer filters harmful solar radiation, including ultraviolet radiation.
Answer: (A)
Q4. Assertion (A): Most meteorites entering from space burn up in the mesosphere.
Reason (R): The mesosphere extends up to approximately 80 kilometres above the Earth’s surface.
Answer: (B)
Q5. Assertion (A): Atmospheric pressure decreases with increasing altitude.
Reason (R): Atmospheric pressure is highest at sea level.
Answer: (B)
Q6. Assertion (A): Wind generally moves from low-pressure areas to high-pressure areas.
Reason (R): Air moves from high-pressure areas to low-pressure areas.
Answer: (D)
Q7. Assertion (A): Temperature generally decreases from the equator towards the poles.
Reason (R): Insolation decreases from the equator towards the poles.
Answer: (A)
Q8. Assertion (A): Humidity refers to the presence of water vapour in the air.
Reason (R): Water vapour plays an important role in cloud formation and precipitation.
Answer: (B)
Q9. Assertion (A): A sea breeze generally blows from the sea towards the land during the day.
Reason (R): During the day, land heats faster than the sea, creating relatively low pressure over the land.
Answer: (A)
Q10. Assertion (A): A land breeze generally blows from the sea towards the land at night.
Reason (R): Land cools faster than the sea at night.
Answer: (D)
Q11. Assertion (A): Weather and climate mean exactly the same thing.
Reason (R): Climate refers to average weather conditions over a long period, usually thirty years or more.
Answer: (D)
Q12. Assertion (A): The Indian climate is strongly influenced by monsoon winds.
Reason (R): Monsoon winds show a seasonal reversal in direction during the year.
Answer: (A)
Q13. Assertion (A): The south-west monsoon generally occurs from June to September.
Reason (R): The south-west monsoon is also known as the summer monsoon.
Answer: (B)
Q14. Assertion (A): The south-west monsoon brings moist winds from the sea towards the land.
Reason (R): During summer, the Indian landmass heats faster than the surrounding oceans, creating relatively low pressure over the land.
Answer: (A)
Q15. Assertion (A): The north-east monsoon is important for rainfall in south-eastern India.
Reason (R): The north-east monsoon winds can pick up moisture while passing over the Bay of Bengal.
Answer: (A)
Q16. Assertion (A): The monsoon has little influence on agriculture in India.
Reason (R): Most of India’s agriculture depends on monsoon rainfall.
Answer: (D)
Q17. Assertion (A): Climate change can cause rising sea levels and the melting of glaciers.
Reason (R): Increased greenhouse gases trap heat and raise global temperatures.
Answer: (A)
Q18. Assertion (A): Deforestation can contribute to climate change.
Reason (R): Deforestation is one of the human activities associated with climate change.
Answer: (A)
Q19. Assertion (A): Walking, cycling and using public transport can help reduce one’s carbon footprint.
Reason (R): A carbon footprint measures the total greenhouse gases released as a result of human activities.
Answer: (B)
Q20. Assertion (A): Heavy monsoon rainfall was one of the natural causes of the Punjab floods discussed in the chapter.
Reason (R): Weak river embankments and construction close to rivers aggravated the damage caused by the floods.
Answer: (B)
