The Dynamic Atmosphere and Changing Climate CLASS 9 SST MCQS, SHORT TYPE, LONG TYPE AND ASSERTION REASON BASED QUESTION AND ANSWER NCERT NEW SYLLABUS 2026-27

 

The Dynamic Atmosphere and Changing Climate

A. MCQs

1. Which layer of the atmosphere contains almost all weather phenomena like rain and storms?

(a) Stratosphere

(b) Troposphere

(c) Mesosphere

(d) Ionosphere

2. The 'Lapse Rate' means the temperature decreases by $1^{\circ}$C for every ___ meters of altitude in the troposphere.

(a) 100 m

(b) 165 m

(c) 500 m

(d) 1000 m

3. Which gas is the most abundant in the Earth's atmosphere?

(a) Oxygen

(b) Nitrogen

(c) Carbon Dioxide

(d) Argon

4. The ozone layer, which protects us from harmful UV radiation, is found in which layer?

(a) Troposphere

(b) Stratosphere

(c) Exosphere

(d) Mesosphere

5. Which instrument is used to measure atmospheric pressure?

(a) Thermometer

(b) Hygrometer

(c) Barometer

(d) Anemometer

6. Meteorites burn up due to friction in which atmospheric layer?

(a) Troposphere

(b) Mesosphere

(c) Ionosphere

(d) Stratosphere

7. What is the primary cause of the 'Greenhouse Effect'?

(a) Nitrogen gas

(b) Ozone depletion

(c) Trapping of solar heat by gases

(d) High wind speeds

8. The average weather condition over a long period (30 years or more) is called:

(a) Weather

(b) Climate

(c) Season

(d) Meteorology

9. Which region in India receives vital rainfall from 'Western Disturbances' during winter?

(a) Southern Peninsula

(b) North and Northwestern Plains

(c) Eastern Coast

(d) Northeastern States

10. 'Mango Showers' are pre-monsoon rains most common in which states?

(a) Punjab and Haryana

(b) Kerala and Karnataka

(c) Odisha and West Bengal

(d) Rajasthan and Gujarat

11. Which greenhouse gas is primarily released by burning fossil fuels?

(a) Oxygen

(b) Carbon Dioxide

(c) Nitrogen

(d) Argon

12. The boundary between the Troposphere and the Stratosphere is called:

(a) Stratopause

(b) Tropopause

(c) Mesopause

(d) Ionopause

13. Which element of weather describes the amount of water vapor present in the air?

(a) Precipitation

(b) Humidity

(c) Pressure

(d) Wind

14. The Himalayas act as a barrier and stop which winds from entering the Indian subcontinent?

(a) Tropical cyclones

(b) Cold Central Asian winds

(c) Southwest monsoon winds

(d) Trade winds

15. What is the 'Loo'?

(a) A cold winter breeze

(b) A seasonal monsoon wind

(c) A strong, hot, and dry summer wind

(d) A cyclonic storm

16. The 'Advancing Monsoon' season in India generally lasts from:

(a) March to May

(b) June to September

(c) October to November

(d) December to February

17. Which city is likely to have a moderate (equable) climate due to the influence of the sea?

(a) Delhi

(b) Mumbai

(c) Jodhpur

(d) Lucknow

18. A carbon footprint is usually measured in units of:

(a) Kilograms of oxygen

(b) Tonnes of $CO_2$ equivalent

(c) Millibars of pressure

(d) Degrees of temperature

19. Which layer of the atmosphere is essential for reflecting radio waves back to Earth?

(a) Troposphere

(b) Ionosphere

(c) Stratosphere

(d) Mesosphere

20. A violent, sudden splash of water caused by dam bursts or thunderstorms is called a:

(a) Tidal wave

(b) Flash Flood

(c) Tsunami

(d) Cyclone

21. Which gas makes up approximately 21% of the atmosphere and supports life?

(a) Nitrogen

(b) Oxygen

(c) Carbon Dioxide

(d) Hydrogen

22. The interval between heavy rainfall and the peak discharge of a flood is known as:

(a) Probability period

(b) Lag-time

(c) Onset type

(d) Catchment period

23. Why is the Stratosphere preferred by pilots for flying commercial jets?

(a) High oxygen levels

(b) Absence of clouds and turbulence

(c) High air pressure

(d) Presence of meteors

24. Which of the following is an example of an 'Indirect Carbon Footprint'?

(a) Driving a car

(b) Emissions from producing your smartphone

(c) Burning wood

(d) Using a gas stove

25. Which Indian organization is responsible for flood forecasting and warnings?

(a) Ministry of Defense

(b) Central Water Commission (CWC)

(c) Indian Railways

(d) ISRO

26. In which atmospheric layer does the temperature increase with height?

(a) Troposphere

(b) Stratosphere

(c) Mesosphere

(d) Exosphere

27. What is the role of dust particles in the atmosphere?

(a) To decrease temperature

(b) To act as nuclei for condensation

(c) To provide oxygen

(d) To block all sunlight

28. The phenomenon of 'October Heat' is a characteristic of which season?

(a) Hot weather season

(b) Retreating Monsoon

(c) Cold weather season

(d) Advancing Monsoon

29. Which of the following is a 'Structural' strategy for flood management?

(a) Mapping flood zones

(b) Constructing Dikes and Levees

(c) Issuing TV warnings

(d) Land-use control

30. Which instrument is used to measure the speed of the wind?

(a) Barometer

(b) Anemometer

(c) Rain Gauge

(d) Hygrometer

31. Methane and Nitrous Oxide are powerful heat-trapping gases produced mainly by:

(a) Solar panels

(b) Agriculture and Livestock

(c) Nuclear plants

(d) Planting forests

32. Which of these cities would experience an 'Extreme' (Continental) climate?

(a) Delhi

(b) Chennai

(c) Kolkata

(d) Kochi

33. A significant and rapid drop in atmospheric pressure usually indicates:

(a) Clear sunny weather

(b) An approaching storm or cyclone

(c) No wind

(d) High humidity

34. The outermost layer of the atmosphere that merges with outer space is the:

(a) Mesosphere

(b) Exosphere

(c) Stratosphere

(d) Troposphere

35. Why is it difficult to breathe on top of high mountains?

(a) Air is too hot

(b) Air is thin and pressure is low

(c) There is too much CO2

(d) Wind is too strong

36. Which of the following is NOT a natural cause of floods?

(a) Heavy rainfall

(b) Deforestation

(c) Cloudburst

(d) Melting glaciers

37. The total area drained by a river and its tributaries is called a:

(a) Catchment area

(b) Drainage Basin

(c) Flood plain

(d) Water divide

38. What is the main human activity responsible for global warming?

(a) Burning fossil fuels

(b) Using solar energy

(c) Organic farming

(d) Recycling waste

39. Which of the following is a 'Non-Structural' flood mitigation method?

(a) Building a dam

(b) Flood Zoning and Mapping

(c) Straightening river channels

(d) Constructing platforms

40. Which layer of the atmosphere is the coldest?

(a) Troposphere

(b) Stratosphere

(c) Mesosphere

(d) Ionosphere

 

B. 3 Marks Questions

1. Why is the Troposphere considered the most important layer of the atmosphere?

• It is the layer closest to Earth where all life forms exist and breathe.
• Nearly 75% to 80% of the atmosphere's total mass is concentrated here.
• All weather phenomena, such as rainfall, clouds, and storms, occur in this layer.
• It contains the water vapor and dust particles necessary for the water cycle.

2. Explain the role of the Stratosphere in protecting life on Earth.

• This layer houses the Ozone Layer, which acts as a shield for the planet.
• It absorbs harmful Ultra-Violet (UV) radiation from the sun.
• Without this layer, UV rays would cause skin cancer and damage plant life.
• The air is thin and stable with no weather disturbances, making it ideal for jet aircraft.

3. Distinguish between Weather and Climate.

• Weather refers to the short-term state of the atmosphere (day-to-day or hour-to-hour).
• Climate is the average of weather conditions over a long period, typically 30 years.
• Weather changes very frequently, while climate remains stable for decades.
• Examples: A "sunny day" describes weather; a "tropical region" describes climate.

4. How does altitude affect the temperature of a place?

• As we move from the surface to higher altitudes, the air becomes less dense.
• Temperature decreases with increasing height at the Normal Lapse Rate (1°C for every 165m).
• This is why mountains like Mussoorie are cooler than plains like Delhi, even in summer.
• Higher altitudes have lower pressure, leading to a drop in the heat-retaining capacity of the air.

5. Describe the importance of Nitrogen in our atmosphere.

• It is the most abundant gas, making up 78% of the atmosphere.
• It is essential for the growth of plants as they require nitrogen to produce proteins.
• It acts as a dilutant for oxygen, preventing rapid and uncontrolled combustion (fires).
• It is indirectly used by humans through the consumption of plants and nitrogen-fixing bacteria.

6. Mention any three features of the Advancing Monsoon (Southwest Monsoon).

• It lasts from June to September and provides the bulk of India's rainfall.
• The winds blow from the high-pressure area of the Indian Ocean toward the low-pressure area of the mainland.
• It is divided into two branches: the Arabian Sea branch and the Bay of Bengal branch.
• It is known for its "breaks," where rain occurs for a few days followed by dry spells.

7. Why does the Tamil Nadu coast receive rainfall in winter?

• During winter, the winds move from the land toward the sea, known as the Retreating Monsoon.
• As these winds cross the Bay of Bengal, they pick up moisture.
• When they reach the Tamil Nadu coast, they cause significant rainfall in October and November.
• This region remains dry during the summer monsoon as it lies in the rain shadow of the Western Ghats.

8. Explain the phenomenon of "October Heat."

• It occurs during the transition period between the rainy season and winter.
• The skies become clear, but the land remains very moist and damp.
• High temperatures combined with high humidity make the weather very oppressive and uncomfortable.
• This condition of daytime heat and stickiness is specifically called "October Heat."

9. Why is the Monsoon called the "Lifeline of India"?

• Indian agriculture is heavily dependent on monsoon rains for irrigation.
• It recharges groundwater levels and fills up rivers and reservoirs used for drinking and electricity.
• A good monsoon leads to a prosperous economy and food security for the country.
• Many Indian festivals and cultural practices are timed around the arrival of the monsoon.

10. What are Western Disturbances and how do they benefit India?

• These are low-pressure systems originating in the Mediterranean Sea.
• They enter India from the northwest during the winter months (December–February).
• They cause much-needed rainfall in the plains and snowfall in the Himalayan region.
• This moisture is extremely beneficial for the growth of Rabi crops, especially wheat.

11. Define "Carbon Footprint" and mention its two types.

• A carbon footprint is the total amount of greenhouse gases (mainly $CO_2$) released due to human activities.
• Direct Footprint: Emissions from activities you control, like driving a car or using a gas stove.
• Indirect Footprint: Emissions related to the life cycle of products you buy, like the energy used to manufacture your clothes.
• It is measured in tonnes of $CO_2$ equivalent.

12. Suggest three ways individuals can reduce their carbon footprint.

• Energy Efficiency: Switch to LED bulbs and energy-star rated appliances to save electricity.
• Sustainable Transport: Use public transport, carpool, or cycle instead of using private petrol vehicles.
• Waste Management: Follow the 3Rs—Reduce, Reuse, and Recycle—to decrease the energy needed for new products.

13. What is Global Warming and mention two of its impacts?

• It is the gradual increase in the Earth's average surface temperature due to the Greenhouse Effect.
• Impact 1: Melting of polar ice caps and glaciers, leading to a rise in sea levels.
• Impact 2: Increased frequency of extreme weather events like heatwaves, cyclones, and floods.

14. How does deforestation contribute to Climate Change?

• Trees absorb $CO_2$ for photosynthesis; cutting them down leaves more $CO_2$ in the atmosphere.
• Burning trees releases the carbon stored within them back into the air.
• Deforestation reduces the "carbon sinks" that naturally balance the Earth’s temperature.

15. Explain the "Greenhouse Effect."

• Greenhouse gases like $CO_2$ and methane act like a glass roof of a greenhouse.
• They allow solar radiation to enter but trap the heat (infrared radiation) from escaping back into space.
• This process keeps the Earth warm enough to support life.
• However, excessive trapping of heat due to pollution leads to global warming.

 

16. Distinguish between Structural and Non-Structural flood mitigation.

• Structural: Involves physical construction like dams, dikes, and embankments to divert water.
• Non-Structural: Involves planning and management, such as flood-plain zoning and mapping.
• Structural methods are often expensive, while non-structural methods focus on reducing risk through policy.

17. Why do urban areas experience frequent flooding?

• Natural soil is replaced by impermeable surfaces like concrete and asphalt.
• Rainwater cannot seep into the ground, leading to massive surface runoff.
• Urban drainage systems are often outdated or blocked by plastic waste and silt.
• Construction on natural floodplains prevents rivers from carrying away excess water.

18. Describe the importance of "Flood Forecasting."

• It provides advance warning to people living in low-lying areas to evacuate.
• It helps authorities manage dam gates and reservoir levels to prevent sudden overflows.
• Early warnings significantly reduce the loss of life and valuable livestock.

19. How does planting trees (Afforestation) help in flood control?

• Tree roots hold the soil firmly, preventing erosion that clogs riverbeds.
• The canopy of trees breaks the force of falling rain, allowing water to drip slowly.
• Trees increase the soil's capacity to absorb water, reducing the volume of surface runoff.

20. Mention the three major causes of floods in India.

• Heavy Rainfall: Intense rain over a short period (Cloudbursts) causes rivers to overflow.
• Cyclones: Strong winds push seawater into coastal areas, causing "Storm Surges."
• Human Factors: Deforestation and unplanned construction near riverbanks block the natural flow of water.

I have compiled the complete set of 20 five-mark questions here. Each answer follows the 5 to 7 point format with the most critical part of each sentence bolded for quick revision.

 

B. 5 Marks Questions

1. Describe the structure of the atmosphere and its significance.

• Troposphere: The lowest layer where all weather phenomena occur and life exists.
• Stratosphere: Contains the Ozone Layer which protects us by absorbing harmful UV radiation.
• Mesosphere: The coldest layer where meteorites burn up due to friction with the air.
• Ionosphere: Part of the thermosphere that reflects radio waves back to Earth for global communication.
• Exosphere: The outermost zone where the air is extremely thin and merges with outer space.
• Atmospheric Filter: Together, these layers maintain a habitable temperature and protect Earth from space debris.

2. Explain the composition of the atmosphere and why it is vital.

• Nitrogen (78%): Essential for plant proteins and prevents uncontrolled combustion (fires).
• Oxygen (21%): Necessary for the respiration of all living organisms.
• Argon (0.9%): An inert gas used in various industrial and lighting applications.
• Carbon Dioxide (0.04%): Vital for photosynthesis and maintaining heat through the greenhouse effect.
• Water Vapor: Acts as a giant blanket to regulate temperature and is the source of all rain.
• Dust Particles: Serve as hygroscopic nuclei around which water vapor condenses to form clouds.

3. Analyze the factors influencing the temperature of a place.

• Latitude: Regions near the equator receive direct sun and are warmer than the poles.
• Altitude: Temperature decreases as height increases at the Normal Lapse Rate ($1^{\circ}$C per 165m).
• Distance from Sea: Coastal areas have a moderate climate, while inland areas have an extreme climate.
• Prevailing Winds: Winds from warm or cold regions can significantly change local land temperatures.
• Ocean Currents: Passing warm or cold currents affect the climate of coastal lands.
• Aspect of Slope: In mountains, slopes facing the sun are warmer than those in the shade.

4. Explain the role of the Ozone Layer and consequences of its depletion.

• Sun Shield: It filters out 99% of the Sun's harmful ultraviolet (UV) radiation.
• Chemical Cause: Depletion is primarily caused by man-made Chlorofluorocarbons (CFCs) from ACs and fridges.
• Human Health: Thinner ozone leads to a rise in skin cancer, cataracts, and weakened immune systems.
• Marine Life: High UV levels damage phytoplankton, which is the base of the ocean food chain.
• Agriculture: It causes reduced crop yields and disrupts the natural growth cycle of plants.

5. Explain the mechanism of the Southwest Monsoon.

• Differential Heating: The Indian landmass heats up faster than the surrounding oceans during summer.
• Low-Pressure Zone: Intense heat creates a strong low-pressure area over North-West India.
• Wind Reversal: Moisture-laden winds from the Southern Indian Ocean rush toward the land.
• Coriolis Force: Winds crossing the equator deflect to the right and enter India as the monsoon.
• Bifurcation: The winds split into the Arabian Sea branch and the Bay of Bengal branch.
• Orography: Barriers like the Western Ghats and Himalayas force winds to rise and cause heavy rain.

6. Compare the Advancing Monsoon and the Retreating Monsoon.

• Direction: Advancing winds blow Sea to Land; Retreating winds blow Land to Sea.
• Timing: Advancing lasts June to September; Retreating occurs in October and November.
• Moisture: Advancing winds are heavy with moisture; Retreating winds are mostly dry.
• Weather: Advancing brings heavy rain; Retreating brings clear skies and "October Heat".
• Regional Focus: Advancing covers all of India; Retreating brings rain only to the Tamil Nadu coast.

7. "The Monsoon is the backbone of the Indian Economy." Justify.

• Irrigation: Over 60% of Indian agriculture depends directly on monsoon rainfall.
• GDP Impact: A strong monsoon results in higher crop yields, boosting the national economy.
• Water Security: It is the primary source for recharging groundwater and filling rivers.
• Power Generation: Reservoirs filled by rain are essential for producing hydroelectricity.
• Price Stability: Good harvests prevent food inflation and ensure food security for the poor.

8. Discuss regional variations in the Indian climate with examples.

• Temperature Range: Rajasthan can reach 50°C in summer, while Dras (Ladakh) drops to -45°C in winter.
• Precipitation: Mawsynram gets 1100 cm of rain, while parts of Rajasthan get less than 12 cm.
• Coastal vs. Interior: Mumbai has a moderate climate, while Delhi experiences extreme heat and cold.
• Seasonal Rain: Most of India gets rain in summer, but Tamil Nadu receives it in winter.
• Himalayan Effect: High altitudes experience an alpine climate with snow, unlike the tropical south.

9. Describe the features of the Cold Weather Season (Winter) in India.

• Duration: Lasts from December to February across most of the country.
• Pressure: A high-pressure area develops over the north, causing winds to blow outward.
• Western Disturbances: These storms from the Mediterranean bring vital winter rain to the plains.
• Rabi Crops: Winter rainfall is extremely beneficial for the growth of wheat.
• Sky Condition: Generally marked by clear skies, low humidity, and pleasant days.
• Frost: Common in the northern plains, while the south remains mild due to the sea.

10. Define Global Warming and explain its major causes.

• Fossil Fuels: The primary cause is the burning of coal and oil, releasing $CO_{2}$.
• Deforestation: Cutting forests reduces the planet's ability to absorb carbon dioxide.
• Methane: Livestock and rice farming release methane, a powerful greenhouse gas.
• Industrialization: Factories emit Nitrous Oxide and other heat-trapping pollutants.
• Waste: Decomposition in landfills produces harmful gases that warm the atmosphere.

11. What are the consequences of Climate Change on a global scale?

• Rising Sea Levels: Melting of polar ice caps threatens to submerge coastal cities.
• Extreme Weather: Increased frequency of super-cyclones, droughts, and floods.
• Ecological Shift: Many animal and plant species face extinction as habitats change.
• Food Crisis: Disrupted weather patterns lead to crop failure and global food shortages.
• Health Hazards: Rise in heatwaves and the spread of tropical diseases like malaria.

12. Explain "Carbon Footprint" and how to reduce it nationally.

• Definition: The total greenhouse gas emissions caused by an individual or nation.
• Renewable Energy: Shifting from coal-fired plants to solar and wind power.
• Public Transit: Investing in electric buses and metros to reduce car emissions.
• Afforestation: Creating large-scale carbon sinks by planting millions of trees.
• Green Building: Using energy-efficient designs and materials in urban construction.

13. How does deforestation contribute to Climate Change?

• Carbon Sink Loss: Trees are natural filters that absorb $CO_{2}$; losing them increases pollution.
• Storage Release: When trees are burned or rot, they release stored carbon back into the air.
• Albedo Effect: Changes in land cover alter how the Earth reflects sunlight, affecting heat.
• Water Cycle: Fewer trees reduce evapotranspiration, leading to local climate drying.
• Soil Carbon: Clearing forests exposes soil, leading to the release of carbon stored in the ground.

14. Analyze the major causes of floods in India.

• Cloudbursts: Intense heavy rainfall in a very short time causes flash floods.
• Siltation: Accumulation of silt on riverbeds reduces the water-carrying capacity.
• Deforestation: Lack of vegetation leads to increased surface runoff and soil erosion.
• Urbanization: Impermeable concrete surfaces prevent rainwater from soaking into the soil.
• Encroachment: Building on natural floodplains blocks the path of water.
• Cyclones: Strong winds push seawater into coastal lands, causing storm surges.

15. Suggest effective measures for flood mitigation.

• Structural: Building dams, dikes, and embankments to physically hold back water.
• Forecasting: Using satellites for early warnings to evacuate people in time.
• Afforestation: Planting trees on slopes and riverbanks to slow down the water flow.
• Zoning: Regulating construction in flood-prone areas through land-use planning.
• Desilting: Regular cleaning of riverbeds to maintain their depth and capacity.

16. Impact of floods on the life and economy of a region.

• Fatalities: Direct loss of life and deaths from water-borne diseases later.
• Infrastructure: Destroys roads, bridges, and power lines, cutting off the region.
• Agriculture: Standing crops are ruined and fertile topsoil is washed away.
• Relief Costs: Huge amounts of money are diverted from development to disaster relief.
• Supply Chain: Floods stop the transport of essential goods, causing price hikes.

17. Why do urban areas experience frequent flooding?

• Concrete Cover: Impermeable surfaces like roads increase water runoff by 90%.
• Drainage: Most city drains are outdated or blocked by plastic waste.
• Lost Wetlands: Ponds and marshes that absorb excess water have been built over.
• Population Density: More people living in low-lying areas increases the disaster risk.
• Industrial Waste: Dumping waste in natural channels blocks the exit of rainwater.

18. Describe the "Normal Lapse Rate" and its significance.

• Definition: The drop in temperature of $1^{\circ}$C for every 165 meters of altitude.
• Reason: The atmosphere is heated from the surface upward, and air is thinner at heights.
• Significance: It explains why hill stations are cool while plains are hot in summer.
• Precipitation: It determines whether a region gets rain or snow at higher altitudes.
• Ecosystems: It creates different vegetation zones on mountains based on temperature.

19. Explain "El Niño" and its impact on the Indian Monsoon.

• Definition: The periodic warming of ocean waters in the eastern Pacific.
• Global Link: It shifts pressure belts across the entire planet's atmosphere.
• Monsoon Weakness: El Niño is strongly linked to monsoon failure or droughts in India.
• Economic Risk: Weak rain leads to crop failure and water shortages for millions.
• Agriculture: It forces farmers to change cropping patterns to avoid total loss.

20. Discuss the relationship between Carbon Footprint and Sustainable Development.

• Sustainability Goal: Developing the world without destroying the environment for children.
• Metric: The carbon footprint is the best way to measure the environmental impact of growth.
• Resource Management: Lowering footprints means using fewer fossil fuels and more green energy.
• Interdependence: Reducing emissions protects the climate stability needed for future food.
• Future Planning: Sustainable cities prioritize low-carbon infrastructure and lifestyles.

 

D. Assertion & Reason Question Bank

Options for all questions:

• (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.

1. Atmosphere Layers

• Assertion (A): The Troposphere is the most important layer of the atmosphere for living organisms.
• Reason (R): It contains the air we breathe and all weather phenomena occur in this layer.
• Answer: (a) Both A and R are true, and R explains why it is most important.

2. Ozone Layer

• Assertion (A): The Ozone layer is found in the Mesosphere.
• Reason (R): Ozone protects the Earth from harmful ultraviolet (UV) radiation from the Sun.
• Answer: (d) A is false (Ozone is in the Stratosphere), but R is a true statement about its function.

3. Indian Monsoon

• Assertion (A): The Southwest Monsoon winds blow from the sea to the land.
• Reason (R): During summer, a low-pressure area develops over the Indian landmass.
• Answer: (a) Both are true; the low pressure on land attracts the moisture-laden winds from the sea.

4. Distance from the Sea

• Assertion (A): Delhi experiences an extreme climate with very hot summers and very cold winters.
• Reason (R): Delhi is located far away from the moderating influence of the sea.
• Answer: (a) This correctly explains the "Continental" type of climate.

5. Western Disturbances

• Assertion (A): Western Disturbances are important for the growth of Rabi crops in North India.
• Reason (R): They bring much-needed rainfall during the winter months of December and January.
• Answer: (a) True; the winter rain from the Mediterranean is vital for crops like wheat.

6. Global Warming

• Assertion (A): Planting more trees (Afforestation) helps in reducing global warming.
• Reason (R): Trees release carbon dioxide into the atmosphere during photosynthesis.
• Answer: (c) A is true, but R is false (Trees absorb carbon dioxide).

7. Altitude and Temperature

• Assertion (A): People prefer to go to hill stations like Shimla and Ooty during the summer.
• Reason (R): Temperature decreases with an increase in altitude at the Normal Lapse Rate.
• Answer: (a) Correct; the height makes these places cooler than the plains.

8. Flood Management

• Assertion (A): Constructing dams and embankments is considered a structural mitigation for floods.
• Reason (R): These methods involve physical engineering to control or divert water flow.
• Answer: (a) True; "Structural" refers to physical building projects.

9. Carbon Footprint

• Assertion (A): An individual's carbon footprint can never be zero.
• Reason (R): Even the production of food and basic clothing involves some level of greenhouse gas emissions.
• Answer: (a) Both are true; since we live in a global economy, almost every activity has an indirect footprint.

10. October Heat

• Assertion (A): The month of October is often uncomfortable in many parts of India.
• Reason (R): High temperature combined with high humidity during the retreating monsoon creates oppressive conditions.
• Answer: (a) This correctly describes the "October Heat" phenomenon.

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