CBSE Class 7 Exploring Society: India and Beyond – Takshila-DPS Pune- Patna-Coimbatore

AUTHOR

Dr. Gauri Kshirsagar

MBBS, DNB (DVL)

Dermatologist, Cosmetologist and Laser Surgeon

Nuleaf Skin Clinic and Hair Transplant Center, Undri, Pune

www.nuleafhair.com

As a mother of twin daughters and a Consultant Dermatologist based in Undri, Pune, life is always a balancing act. Between busy clinic hours, parenting duties, and everyday chaos, I’ve been creating study notes since Class 4 to help my girls understand and revise their lessons better. Over the years, these weekend study sessions turned into a special tradition—discussing topics taught in school and turning them into organized, easy-to-revise notes.

The notes I’m sharing here are from the 2025–26 academic year of DPS Pune – Patna – Coimbatore, and cover Class 7 chapters. They include all the key points that are likely to be asked in exams, compiled from the Class 7 Exploring Society:India and Beyond , school study materials, class notes and school revision sheets.

Each page was made with care, love, and a hope to make learning feel a little easier—especially during exam time. If they help your child too, then this effort finds even more meaning.

If you find these notes useful, I’d love to hear from you in the comments section. And if you’d like me to upload notes on any particular topic from Class 7, feel free to send in your suggestions.
Don’t forget to subscribe to my blog for new updates, notes, and posts.

Wishing you and your child a wonderful academic year ahead!Warmly,
Gauri
Mom to twins

Understanding the Weather

A change in the weather is sufficient to create the world and oneself anew.

– Marcel Proust, French novelist

Layers of the Atmosphere

Atmosphere (Defⁿ): it is the layer of gases that surround some planets — in the case of our Earth, we call these gases ‘air’. 

Structure of the atmosphere: Atmosphere is divided into five distinct layers –

Layer	Height / Extent	Key Features	Temperature/ Pressure
Troposphere	Equator: up to 18 km; Poles: up to 8 km	Lowest & densest layerZone of all weather changesAll land-based plants and animals live and breathe.	Both Pressure and temperature in this layer decreases with increasing altitude.
Stratosphere	Extends up to 50 km	Contains Ozone layerIdeal for jet planes due to calm conditions	The temperature remains constant up to a height of 20 km and then increases with increasing altitude.
Mesosphere	Extends up to 80 km	It is the coldest layer in the atmosphere  (-100°C at 80 km)Meteorites burn up in this layer.	The temperature decreases with height and reaches about -100°C at the height of 80 km.
Thermosphere	Extends between 80Km to 400 km	Reflects radio waves dueto charged particles called ions.   – Contains charged particles (ions) that reflect radio waves- Temperature > 1,500°C	In this layer the temperature increases rapidly with the increasein height. It reaches more than 1,500 ºC.
Exosphere	Beyond 400 km, merges into outer space	Outer layer of the atmosphere which merges with the atmosphere of other planets. The density of air in this layer is very low.	The temperature increases with height and may reach 4,500 ºC.

Q) To what height does the troposphere extend, and how does its thickness vary between the poles and the tropical zone?

Ans) The troposphere extends to a height of 6 to 18 kilometers from the ground; it is less thick at the poles (where the cold air contracts) and thicker in the tropical zone (where the warmer air expands). 

Weather

Definition: Weather refers to the state of the atmosphere at a specific time and place, influenced by temperature, humidity, wind, and more.

The elements of weather are:

1. Temperature: How hot or cold the atmosphere is.
2. Precipitation: Any form of water, such as rain, snow, sleet or hail, that falls from the sky.
3. Atmospheric Pressure: The weight of the air above us, felt on the Earth’s surface.
4. Wind: The movement of air, including its speed and direction.
5. Humidity: The amount of water vapour in the air.

Forecasting Weather

Forecast: To predict or find out in advance (in our case, the weather).

Traditional Weather Forecasting

1. From early times, humans observed Nature’s signals to predict weather.
2. Examples of natural signs:
   1. Birds flying low → sign of rain/storm.
   1. Ants carrying eggs → indicates heavy rain (ants move eggs to higher ground).
   1. Squirrels gathering nuts → sign of seasonal change.
   1. Frogs croaking loudly → expectation of rain (esp. in Western Ghats).
   1. Pine cones opening/closing → controlled by humidity:
      1. Close in humid conditions (protect seeds).
      1. Open in dry conditions (release seeds for spreading, ensuring they spread in favourable weather).

Knowledge Transfer

1. Weather-reading skills were passed from generation to generation.
2. Even today, in many parts of India, people use traditional methods to predict weather, especially monsoon arrival.
3. Examples:
4. Snow melts quickly when it’s warm.
5. Cloudy weather ―it’s getting cold.
6. In winter, coconut oil turns solid.
7. Curd takes longer to set in cold weather.

Measuring Weather

Meteorology (Defⁿ): Meteorology is the systematic scientific study of weather, its evolution, and the physical processes and phenomena taking place in the earth’s atmosphere. It forms the basis of weather forecasting, and meteorologists study the different layers of the atmosphere to understand these changes.

The India Meteorological Department:

1. The India Meteorological Department was set up in 1875.
2. Its motto is ādityāt jāyate vriṣhti, which means, “From the sun arises rain.”
3. The phrase comes from the ancient text Manusmṛiti, and the complete sentence reads, “From the sun arises rain, from rain comes food, and from food, living beings originate.”

Weather Instruments

1. Temperature

1. Temperature (Defⁿ): How hot or cold the atmosphere is.
2. Instrument: Measured using thermometers.
3. Types of thermometers:

3. Some measure only ambient temperature.
4. Some record maximum & minimum temperatures of the day.
5. Working: Many use coloured liquid that expands with heat;  
6. Digital thermometers are preferred as they are more precise, safe and can record more data.
7. Uses: Temperature recordings help calculate:

1. Range of temperature = Maximum – Minimum temperature (over 24 hrs).
2. Mean daily temperature = (Maximum + Minimum temperature) ÷ 2.

2. Precipitation

• Precipitation (Defⁿ): Any form of water, such as rain, snow, sleet or hail, that falls from the sky.Instrument: The amount of rainfall is measured with the help of an instrument called a rain gauge Working: When it rains, the water falls into a funnel and is collected in a cylinder. A scale is attached to the cylinder to measure the depth of rainwater collected.

• Example: If height of collected water = 5 mm, then area received 5 mm rainfall.

3. Atmospheric Pressure

1. Definition: Pressure exerted by the weight of air above and around us.
2. Variation:
   1. Higher near sea coast.
   1. Lower in mountains (air thinner → less oxygen → breathlessness, dizziness, tiredness at high altitudes).
3. Low pressure: Sometimes occurs in plains/coasts → causes ‘depression’ or low-pressure system → may develop into storm or cyclone.
4. Instrument: The instrument used to measure atmospheric pressure is called a barometer. Units: Millibar (mb).
   1. Normal atmospheric pressure at sea level: 1013 mb, below 1000 mb = Depression.
5. Acclimatization: People who journey to places at a high altitude are advised to make pauses on the way to allow the body to acclimatize.
6. Our army personnel serve in high-altitude places like Khardung la in Ladakh, which is over 5600 metres above sea level. It is hard to imagine how they live and work in places where the oxygen level is so low — the atmospheric pressure there is generally about 650 millibars!

Q) Why do some people feel breathless, dizzy or tired at high altitudes?

Ans)

1. The atmospheric pressure is higher near the sea coast and lower at higher altitudes in the mountains.
2. At high altitudes (while climbing a mountain), the air becomes thinner than in the plains below.
3. As a result, the air pressure is lower, and less oxygen is available for the lungs to take in.
4. With less oxygen entering the blood, the body has to work harder to function. Therefore, some people feel breathless, dizzy, or tired at high altitudes.

Q) How does a storm/cyclone form?

Ans)

1. The Atmospheric pressure is not always high in the plains below or on the coast.
2. Sometimes it drops dramatically, resulting in what meteorologists call a ‘depression’ or ‘low-pressure system’, which can sometimes develop into a storm or even a cyclone.
3. Normal atmospheric pressure at sea level: 1013 mb, below 1000 mb = Depression.

4. Wind

1. Definition: Wind is the movement of air from areas of high pressure to areas of low pressure.
2. Important factors: Speed and direction are two important factors when we describe the wind.
3. Uses:
   1. Its direction and speed help in weather forecasting.
   1. Air pilots and sailors need to be aware of wind data, as the wind has a great influence on flying or sailing. 
   1. Farming:
      1. Farmers also use the wind direction to predict where rain might come from.
      1. A greater wind speed will cause the soil to dry faster.
4. Instruments:
   1. Wind vane (weather vane):  
      1. A wind vane (or weather vane) has a rotating arm with a pointer at one end and a tail at the other.
      1. When the wind blows, the tail is pushed, and the pointer turns in the direction of the wind.
      1. It responds even to a light breeze.
   1. Wind sock:
      1. This wind vane on the tarmac is called a ‘wind sock’. It gives pilots an indication of the direction of the wind during take-off and landing.
      1. Similar socks are used in industries that release ash or gases.
   1. Anemometer:
      1. The simplest instrument to measure the wind direction and speed is the anemometer.
      1. It has three or four metal cups that rotate on a vertical shaft when the wind blows — the stronger the wind, the faster the rotation.
      1. A meter attached at the bottom counts how many times the anemometer spins in a certain period of time and calculates the wind speed in kilometres per hour (km/h).

5. Humidity

1. Definition: Amount of water vapour in the air is called humidity
2. Depends on: It also depends on factors like temperature, wind, pressure and location.
3. Measurement: This is done through an instrument called a hygrometer.
   1. Measured as relative humidity:
      1. 0% = completely dry air.
      1. 100% = fully saturated air.

• Ranges:
  • Dry weather: 20–40% relative humidity
  • Humid weather: 60–80% relative humidity
• Important points:
• When water evaporates, it causes a cooling effect.
• If the amount of water in the air is already high (more humidity), water evaporates slowly. That is typically the case on a rainy day.
• Application:
  • The measurement of humidity is of great importance in many industrial processes, such as food processing.
  • Museums also monitor humidity as they need to maintain a dry environment to preserve their exhibit.

Q) Where do you think humidity is likely to be more, Kochi or Jaipur? You might guess that Kochi has higher humidity than Jaipur because it is located near the sea. But how will we know for sure? 

Ans) Kochi has higher humidity because it’s by the sea, and Jaipur has low humidity because it’s far from the sea. To compare two places, measure humidity with a hygrometer at both locations and compare the numbers.

Q) If the humidity in Delhi is at 52% while in Kochi it is 84%, in which of the two places are wet clothes likely to dry faster? And where are you likely to sweat more, assuming the temperature is the same in both places?

Ans)

Where Clothes Dry Faster

• In Delhi, the air is drier (lower humidity), so there’s more room for water vapor from the clothes to escape into the air.
• In Kochi, the air is very humid (high humidity), which means the air is already holding a lot of water vapor and cannot absorb much more, so clothes take longer to dry.

Where Sweating Feels Stronger

• In Kochi, because the air is so humid, sweat doesn’t evaporate easily from the skin, so it feels stickier and sweatier.
• In Delhi, with less humidity, sweat evaporates quickly, making it feel less sweaty even if the temperature is the same.

Weather Stations

Weather Station:  A weather station brings all these instruments together, making it easy to measure and track the weather. Readings of all the measurements are taken at regular intervals, which helps in mapping and forecasting the weather.

Automated Weather Station: An Automated Weather Station (AWS) is a self-operating system that uses various sensors to measure and record weather data, such as temperature, humidity, wind speed and direction, precipitation, and atmospheric pressure.

Uses: Such stations are widely used to provide accurate and timely weather information without the need for human intervention in fields like:

1. Agriculture,
2. Aviation,
3. Navigation,
4. Environmental monitoring, and so on,

In 2023, the National Disaster Management Authority set up an AWS at a glacial lake of Sikkim at an altitude of more than 4800 metres above sea level. The AWS provides early

information about upcoming weather conditions.

Predicting the Weather

1. Traditional Methods

Observing nature (e.g., ants moving eggs = rain coming, pine cones closing = humidity).

• Modern Technology
  • Automated Weather Stations (AWS): Sensors track real-time data (temperature, wind, etc.).
  • Satellites & Radars: Monitor large-scale weather patterns.

Why Predictions Matter:

1. Predictions are very important nowadays, as climate change makes extreme weather, such as droughts, floods, cyclones, etc., more frequent. Accurate predictions help us to be ready for such events.
2. They also enable local governments to mobilize resources and prepare for any disasters.
3. For example, if stormy weather is expected at sea, fishermen are warned about venturing out in their boats, or an entire coastal area might have to be evacuated if a cyclone is expected.

Example: India’s Weather Alerts (May 2024)

Color Codes:

1. Green = Normal
2. Yellow = Watch (Be updated)
3. Orange = Alert (Be prepared)
4. Red = Warning (Take action)

Extreme Weather Examples:

1. Heatwaves (High temperatures)
2. Cyclones (Low pressure + strong winds)
3. Heavy Rain/Snow (Floods or avalanches)

Definitions:

1. Sleet: Frozen or partly frozen rain.
2. Hail: Small, hard balls of ice that fall from the sky like rain.
3. Water vapour: Water vapour is water in gaseous instead of liquid form.
4. Forecast: To predict or find out in advance (in our case, the weather).
5. Ambient: Of the immediate surroundings.
6. Statistics: The technique of gathering and analysing information or data in order to be able to detect patterns, understand events or make predictions.

Key Takeaways

1. Weather is a mix of temperature, wind, rain, pressure, and humidity.
2. Tools like thermometers and barometers help measure it accurately.
3. Predictions save lives by preparing for disasters.
4. Climate change is making extreme weather more common.
5. Temperature, humidity, precipitation, wind and atmospheric pressure together define the weather at a particular place.
6. The condition of these elements is measured using special instruments. Data collected from these help us to monitor and predict the weather.
7. In different times or situations, one of the elements is dominant — for example, rainfall in July, the temperature in May and December, atmospheric pressure when a cyclone is moving, and wind when a loo (strong, hot and dusty winds that blow in north India in summers) is blowing, or forest fires are spreading. Weather is closely linked to climate.

SCM Q & A

MCQs

1. Which layer of the atmosphere is closest to Earth’s surface?

a) Stratosphere

b) Mesosphere

c) Troposphere

d) Thermosphere

2. What instrument measures atmospheric pressure?

a) Hygrometer

b) Barometer

c) Anemometer

d) Thermometer

3. Low atmospheric pressure (below 1000 mb) usually indicates:

a) Clear skies

b) Storms or cyclones

c) Extreme heat

d) Frost

4. Which weather element is measured using an anemometer?

a) Humidity

b) Wind speed and direction

c) Rainfall

d) Temperature

5. Traditional weather prediction methods include observing:

a) Ants moving eggs

b) Solar eclipses

c) Moon phases

d) Ocean tides

6. Ants shifting their eggs to higher ground is a natural behaviour that indicates

(a) extreme heat

(b) expected heavy rain

(c) both a and b are correct

7. ______predict how the weather will behave in a particular region after a few hours or a few days, or even a few weeks.

(a) Geologists

(b) Archaeologists

(c) Meteorologists

8. The amount of rainfall is measured with the help of an instrument called a _______

(a) hygrometer

(b) rain gauge

(c) cylinder

9. The atmospheric pressure is higher__________

a. Near the sea coast

b. Top of the mountains

c. Both b and c

10. The two important factors when we mention the wind are

a. speed and weight

b. speed and direction

c. pressure and direction

Answer the following questions: [2 marks]

1. Draw a neat labeled diagram of the layers of atmosphere.

2. People sometimes feel breathless, dizzy on high altitudes. Give reason.

3. How does wind affect farming?

4. Explain the working of the Automated Weather Station.

5. Draw a neat labeled diagram of the rain gauge. [3 marks]

6. Name and explain all the elements of weather.

7. Explain the working of the rain gauge

8. Explain wind. How do we measure wind?

9. Define humidity. Why do we measure it as relative humidity?

10. Write the importance of weather forecasting.

11. Write the difference between atmospheric pressure and wind.

	Atmospheric Pressure	Wind
Definition	Pressure exerted by the weight of the air above and around the earth.	Movement of air from areas of high pressure to areas of low pressure.
Variation	Higher near the sea coast; lower at high altitudes (mountains).	Depends on speed and direction of air movement.
Instrument	Measured with a barometer.	Measured with wind vane, wind sock, or anemometer.
Unit / Factors	Unit: Millibar (mb). Normal sea-level pressure ≈ 1013 mb; below 1000 mb indicates depression.	Described by speed and direction.
Importance	Sudden fall can cause storms or cyclones.	Important for weather forecasting, pilots, sailors, and farmers.
Effect	Low oxygen at high altitudes → breathlessness, dizziness, tiredness.	High speed winds dry soil faster and influence rainfall.

TEXTBOOK Q & A

1. Match the instrument with the weather element it measures. Instrument used Element of the Weather

Ans)

1. (1) Hygrometer → (d) Humidity
2. (2) Anemometer → (c) Wind direction and speed
3. (3) Barometer → (b) Atmospheric pressure
4. (4) Thermometer → (e) Temperature
5. (5) Rain gauge → (a) Precipitation

2.Jyotsna is deciding what clothes to pack for her school trip to Mumbai in June. She looks at the weather forecast, which predicts 29°C and 84% humidity. What would be your advice to her?

Ans)

1. Carry light cotton clothes (to stay cool in humid weather).
2. Keep a raincoat or umbrella (as June is monsoon season).
3. Comfortable sandals or shoes suitable for rain.
4. Carry a water bottle to stay hydrated.

3. Imagine that a small group of students is setting up a rain gauge.

Here are some options for the site.

1. The school vegetable garden.

2. The terrace of the school building.

3. Open ground with elevated platform.

4. Compound wall of school.

5. Verandah of the school laboratory.

Discuss in your group and finalize the site. Write down the reasons for your decision.

Ans)

1. Open ground ensures the rain gauge is not obstructed by trees, walls, or buildings.
2. Elevated platform prevents splashes of mud or water from entering the gauge.
3. Provides accurate measurement of rainfall without interference.
4. Other sites (terrace, verandah, wall, garden) may have obstructions or water run-off affecting accuracy.

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