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A group of students is planning a trekking trip to the Himalayas. They are concerned about the varying temperatures and air pressure at different altitudes. Considering the structure of the atmosphere, which layer would they experience the most significant changes in temperature and air density during their ascent?(a) Stratosphere(b) Troposphere(c) Mesosphere(d) Thermosphere1mark
2
A pilot is planning a long-haul flight. To ensure a smooth journey and minimize turbulence, in which layer of the atmosphere would they ideally fly the aircraft and why?(a) Troposphere, because it's closest to Earth and has the clearest air.(b) Stratosphere, because it is relatively calm and free of weather disturbances.(c) Mesosphere, because it offers less resistance to aircraft.(d) Exosphere, because it has the thinnest air.2marks
3
A meteorologist observes that the atmospheric pressure at a coastal city has dropped significantly, and the sky is becoming cloudy with a chance of rain. Based on this information and the concept of atmospheric pressure, what type of weather can be predicted?(a) Clear and sunny skies due to high pressure.(b) Strong winds blowing from land to sea.(c) Cloudy skies and potential rainfall associated with low pressure.(d) Very cold temperatures.2marks
4
Assertion: The Earth's atmosphere is crucial for life.Reason: It protects us from harmful solar radiation and regulates temperature.(a) Both assertion and reason are true, and the reason is the correct explanation of the assertion.(b) Both assertion and reason are true, but the reason is not the correct explanation of the assertion.(c) Assertion is true, but the reason is false.(d) Assertion is false, but the reason is true.1mark
5
Case Study: A documentary filmmaker is shooting a segment on the Aurora Borealis. They are currently in the Arctic region and are witnessing a spectacular display of coloured lights in the night sky.(a) In which layer of the atmosphere does the Aurora Borealis phenomenon occur?(b) What causes these colourful lights?(c) Explain the origin of the word "aurora".3marks
6
Identify the process where water vapour in the atmosphere condenses and falls to the Earth as rain, snow, sleet, or hail.(a) Evaporation(b) Transpiration(c) Precipitation(d) Condensation1mark
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Application: Imagine you are designing a weather forecast system. You need to predict the likelihood of rainfall. What atmospheric element, besides temperature, would be most critical to monitor for this prediction?(a) Wind speed(b) Water vapour content (humidity)(c) Atmospheric pressure(d) All of the above2marks
8
A scientist is studying the climate of a region and observes that the average temperature, humidity, and wind patterns over the last 30 years show a consistent trend. What term is used to describe this long-term pattern?(a) Weather(b) Climate(c) Atmosphere(d) Precipitation1mark
9
Assertion: India's climate is best described as tropical monsoon.Reason: This is primarily due to the influence of the south-west and north-east monsoon winds.(a) Both assertion and reason are true, and the reason is the correct explanation of the assertion.(b) Both assertion and reason are true, but the reason is not the correct explanation of the assertion.(c) Assertion is true, but the reason is false.(d) Assertion is false, but the reason is true.1mark
10
Data Interpretation: A student analyzes the table of average monthly temperatures and rainfall for different Indian cities. They notice that Delhi has much lower rainfall in January compared to July, while Thiruvananthapuram shows relatively consistent rainfall throughout the year, with peaks during certain months.(a) What is the most likely reason for the significant difference in rainfall between January and July in Delhi?(b) What term describes the climate of Thiruvananthapuram, based on its temperature pattern?3marks
11
During summer in India, the landmass heats up faster than the surrounding oceans. This creates a low-pressure area over the Indian subcontinent. What type of winds will blow and from where, leading to rainfall?(a) Cold, dry winds from land to sea.(b) Moist winds from the ocean towards the land.(c) Cold, moist winds from the Himalayas.(d) Hot, dry winds from the desert regions.2marks
12
Situational Analysis: A farmer in Rajasthan is concerned about their crops due to a prolonged dry spell. The local weather forecast indicates a weak monsoon. What are the potential consequences of a weak monsoon for the region?(a) Excessive rainfall leading to floods.(b) Sufficient water supply for crops and increased agricultural yield.(c) Drought conditions and reduced agricultural yield.(d) Moderate temperatures and pleasant weather.2marks
13
Scenario: A new residential colony is being developed near a riverbank. Environmental experts are advising the developers on potential risks. Considering the information on floods in Punjab (2025), what human-made factor could aggravate flood damage in this new colony?(a) Heavy monsoon rains.(b) Weak and old river embankments.(c) Building houses and farms too close to the river.(d) Silt accumulation in the river.2marks
14
The term 'mausim', from which the word 'monsoon' is derived, literally means:(a) Season(b) Wind(c) Rain(d) Storm1mark
15
Application: A country is experiencing rising global temperatures, melting glaciers, and sea-level rise. These are identified as consequences of human activities. What is the overarching term for these long-term changes in weather patterns?(a) Seasonal variation(b) Climate change(c) Weather fluctuations(d) Atmospheric disturbance1mark
16
Source-Based: According to the passage, which two gases are the primary and most abundant gases in the Earth's atmosphere and are essential for life?(a) Carbon dioxide and Argon(b) Nitrogen and Oxygen(c) Helium and Neon(d) Ozone and Hydrogen1mark
17
Assertion: Reducing our carbon footprint is crucial for mitigating climate change.Reason: Human activities like burning fossil fuels increase greenhouse gases, trapping heat and raising global temperatures.(a) Both assertion and reason are true, and the reason is the correct explanation of the assertion.(b) Both assertion and reason are true, but the reason is not the correct explanation of the assertion.(c) Assertion is true, but the reason is false.(d) Assertion is false, but the reason is true.1mark
18
Case Study: A student is filling out a questionnaire to calculate their carbon footprint. Under the 'Transport' section, they tick 'I use public transport/carpool.' Under 'Electricity Use', they tick 'I always switch off electrical appliances when not in use.' And for 'Waste and Plastics', they tick 'I reuse, recycle, and avoid single-use plastics.'(a) What is the likely impact level (Low, Medium, High, Very High) associated with each of their choices?(b) What would be their total score if 'Medium impact' choices are worth 2 points?3marks
19
Explain why the density of air is highest near the Earth's surface and decreases with altitude. 3marks
20
Distinguish between the characteristics of the south-west monsoon and the north-east monsoon in India. 3marks
Answers
1
(b) Troposphere. The troposphere is the lowest layer, where most of the weather phenomena occur, and temperature and density change significantly with altitude.1mark
2
(b) Stratosphere, because it is relatively calm and free of weather disturbances. The stratosphere is known for its stability and lack of turbulence, making it ideal for aviation.2marks
3
(c) Cloudy skies and potential rainfall associated with low pressure. Low atmospheric pressure is generally associated with unstable weather conditions, including cloud formation and precipitation.2marks
4
(a) Both assertion and reason are true, and the reason is the correct explanation of the assertion. The atmosphere's protective and regulatory functions are vital for life on Earth.1mark
5.
(a) The Aurora Borealis phenomenon occurs in the Thermosphere.
(b) The colourful lights are caused by charged particles from the solar wind interacting with different atmospheric gases in the thermosphere.
(c) The word 'aurora' originates from Latin, meaning 'dawn' or 'morning light', named after the Roman goddess of dawn.
[3 marks]
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(c) Precipitation. Precipitation is the collective term for water falling from the atmosphere to the Earth's surface.1mark
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(d) All of the above. Temperature, humidity, wind speed, and atmospheric pressure all play roles in weather patterns and influence the likelihood of rain.2marks
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(b) Climate. Climate refers to the average weather conditions over a long period in a specific region.1mark
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(a) Both assertion and reason are true, and the reason is the correct explanation of the assertion. The monsoon winds are the dominant factor shaping India's tropical monsoon climate.1mark
10.
(a) The significant difference in rainfall between January and July in Delhi is due to the seasonal reversal of monsoon winds. Delhi experiences monsoon rains primarily during the summer months (July-September) brought by the south-west monsoon. January is part of the dry winter season.
(b) The climate of Thiruvananthapuram, with its relatively consistent temperature throughout the year and noticeable rainfall peaks, can be described as equable or tropical.
[3 marks]
11
(b) Moist winds from the ocean towards the land. The temperature difference between the heated land (low pressure) and cooler oceans (high pressure) causes moist winds to blow from the sea to the land.2marks
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(c) Drought conditions and reduced agricultural yield. A weak monsoon means less rainfall, leading to water scarcity, impacting crop growth and potentially causing drought.2marks
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(c) Building houses and farms too close to the river. This reduces the natural space for floodwaters to spread, increasing the risk of damage to infrastructure and property when floods occur.2marks
14
(a) Season. The Arabic word 'mausim' translates to season, from which 'monsoon' is derived, signifying the seasonal reversal of winds.1mark
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(b) Climate change. Climate change encompasses long-term shifts in temperature and weather patterns, largely driven by human activities.1mark
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(b) Nitrogen and Oxygen. These are the two most abundant gases in the atmosphere and are essential for supporting life.1mark
17
(a) Both assertion and reason are true, and the reason is the correct explanation of the assertion. The increase in greenhouse gases due to human activities directly causes global warming and climate change.1mark
18.
(a)
Transport: 'I use public transport/carpool.' - Medium impact (2 points)
Electricity Use: 'I always switch off electrical appliances when not in use.' - Low impact (1 point)
Waste and Plastics: 'I reuse, recycle, and avoid single-use plastics.' - Low impact (1 point)
(b) Total score = 2 (Transport) + 1 (Electricity) + 1 (Waste) = 4 points.
[3 marks]
19
The density of air is highest near the Earth's surface because the weight of the entire column of air above it exerts pressure, compressing the air molecules closer together. As altitude increases, the weight of the overlying air column decreases, resulting in less compression and therefore lower air density.3marks
20.
South-West Monsoon:
- Blows from sea to land.
- Occurs between June and September.
- Characterised by moist winds bringing most of the rainfall to India.
- Caused by the unequal heating of land and sea, creating low pressure over India.
North-East Monsoon:
- Blows from land to sea.
- Occurs between October and February.
- Generally cold and dry winds, bringing little rainfall to most of India.
- Causes rainfall in the eastern coast (Tamil Nadu, Andhra Pradesh, parts of Karnataka) when passing over the Bay of Bengal.
- Caused by the cooling of the Indian landmass, creating high pressure over land.
[3 marks]
