Solutions-NCERT-Class-7-Social Science-Part : 1-Chapter-2-Understanding the Weather-CBSE

We can measure and monitor the weather using weather instruments and weather stations.

(i) Using Weather Instruments :

Different instruments are used to measure different elements of weather:

• Thermometer → measures temperature
• Rain Gauge → measures rainfall
• Barometer → measures air pressure
• Anemometer → measures wind speed
• Wind Vane → shows wind direction
• Hygrometer → measures humidity

(ii) Using Weather Stations : A weather station has all these instruments in one place. It records weather data regularly.

Weather predictions help us prepare for extreme events by providing early warnings that allow for the mobilization of resources and timely action. These predictions are increasingly vital as climate change makes extreme weather more frequent. Preparation efforts include:

• Storms and Cyclones: Predictions allow local governments to issue warnings to fishermen against going to sea and, if necessary, to evacuate entire coastal areas.
• Heavy Rain and Flooding: Forecasting enables authorities to prepare for potential disasters and manage resources effectively to assist affected populations.
• Heat Waves and Drought: Accurate data helps in monitoring these conditions, allowing for advanced planning in agriculture and environmental management.
• Safety in Travel and Industry: Pilots and sailors rely on wind and pressure data for safe navigation, while industries use wind socks to monitor the spread of released gases or ash

Here are some common Hindi words used to describe weather, similar to English words like hot, cold, pleasant, etc.

If we know the weather a few hours or days in advance, we can make smarter decisions in daily life. Here are some important reasons:

• Planning daily activities : We can decide what to wear (carry an umbrella, wear warm clothes, etc.). Plan outdoor activities like picnics, sports, or trips. Avoid going out during heavy rain or extreme heat
• Helping farmers : Farmers can plan when to sow seeds, water crops, or harvest. They can protect crops from storms, frost, or drought.
• Travel and transport : Helps people plan journeys and avoid delays. Pilots, train drivers, and ship captains rely on weather forecasts for safety
• Safety and disaster preparedness : Early warnings about storms, cyclones, floods, or heat waves help save lives. People can take precautions like staying indoors or moving to safe places
• School and events planning : Schools can plan sports days or outdoor activities. Organizers can manage events like fairs, weddings, or matches

Accurate weather measurement helps us stay prepared, safe, and organized in our daily life.

• Maximum Temperature: The highest temperature recorded during the week was 32°C (on 03.03.2025).
• Minimum Temperature: The lowest temperature recorded during the week was 14°C (on 05.03.2025).
• Range of Temperature: The range is calculated by subtracting the minimum temperature from the maximum temperature.
  • Calculation: 32°C - 14°C = 18°C,.

• Amir would likely feel surprised or amused because 20°C would seem pleasant or even warm to him in Kashmir.
• This shows that the feeling of “cold” is subjective and depends on what a person is used to.
• While someone from a warmer place like Chennai may feel cold at 20°C, a person from a colder region like Kashmir finds it comfortable.
• Using a standard temperature like 20°C helps both understand the weather clearly, even if their experiences are different.

Kochi is likely to have higher humidity than Jaipur because Kochi is a coastal city near the sea, while Jaipur is inland and has a drier climate.

But instead of just guessing, we can know for sure by measuring humidity.

How to compare humidity:

• Use an instrument called a hygrometer (or humidity sensor)
• Measure the relative humidity (%) in both places at the same time
• Compare the readings

Example: If Kochi shows 80% humidity and Jaipur shows 30%, then Kochi is more humid.

Comparing Kochi and Mangaluru:

• Both are coastal cities, so both will have high humidity. To compare:
• Take humidity readings in both cities at the same time and under similar conditions
• The city with the higher percentage value has more humidity

So, accurate measurement using instruments helps us compare humidity instead of just relying on assumptions.

(a) On that day, the IMD is warning people about different severe weather conditions like heavy rain, heat waves, Hot and Humid, thunder and lightning and Strong Surface Winds.

(b) The states which are having warning signs are Kerala, Tamil Nadu, Rajasthan, Punjab Haryana and Delhi and others.

(c) North-East part of India is to be free form serve weather conditions.

(d) The states which are likely to face heat wave conditions are Madhya Pradesh, Rajasthan, Haryana, Punjab, Uttar Pradesh, West Bengal, Tamil Nadu and many more.

(e) Causes for warnings in Tripura and Lakshadweep

• Tripura Thunder and lightning is the cause of concern.
• Lakshadweep Heavy rain, Thunder and Lightning is the cause of concern.

• Krishnan should explain the cold by giving an exact temperature, instead of just saying “it is chilly.”
• For example, he can say: “The temperature here is about 20°C.”
• This way, Amir can clearly understand how cold it is, even if his personal feeling is different. While Krishnan may feel chilly at 20°C, Amir (who lives in a colder place like Kashmir) might find it quite pleasant.
• So, using measured values like temperature helps avoid confusion and gives a clear idea of the weather to everyone.

Measuring atmospheric pressure is important because it helps us understand and predict changes in the weather.

Why it is important :

• Weather forecasting: A drop in pressure often means rain or storms are coming, while high pressure usually means clear weather.
• Early warnings: Helps predict cyclones, storms, and other extreme events in advance
• Understanding climate: Scientists study pressure patterns to understand how the atmosphere behaves

Who uses it :

• Meteorologists (weather scientists) to predict weather
• Pilots and aviation staff to ensure safe flying (air pressure affects altitude)
• Sailors and fishermen to avoid storms at sea
• Mountaineers to understand altitude and oxygen levels
• Farmers to plan farming activities based on weather changes

Yes, many seeds are carried by the wind—like those of cotton, dandelion, or maple. They are light and often have wings or fluffy parts that help them float.

If there were no wind:

• The seeds would fall straight down near the parent plant.
• They would not spread far, so new plants would grow very close together.
• This could lead to overcrowding, with plants competing for sunlight, water, and nutrients.
• As a result, fewer plants might survive.

So, wind helps in seed dispersal, allowing plants to spread to new places and grow better.

Wet clothes will dry faster in Delhi because it has lower humidity than Kochi. In Kochi, the air already has more water vapour, so it is harder for moisture to leave the clothes. You are also likely to sweat more in Kochi because sweat doesn't dry quickly in humid air, making you feel hotter.

1-(d), 2-(c), 3-(b), 4-(e), 5-(a)

Since the forecast for Mumbai is 29°C with 84% humidity, the weather will feel hot and sticky (humid).

Advice for Jyotsna:

• Wear light, loose cotton clothes – they absorb sweat and keep the body cool
• Choose light colours (like white or pastel shades)
• Carry an extra set of clothes because humidity can make you sweaty
• Take a cap/hat and sunglasses for sun protection
• Keep a handkerchief or towel
• Wear comfortable sandals or breathable shoes
• Carry a water bottle to stay hydrated
• Since June may have rain, pack a light raincoat or umbrella

Overall, she should pack clothes that are cool, comfortable, and suitable for humid weather.

• After discussing with the group we have come to conclusion that the best place to set up a rain gauge is the open ground with an elevated platform.
• This is because it is out in the open, away from walls and roofs, so rain can fall into it properly without anything blocking it.

Jammu and Kashmir on February 1, 2024, weather report script:

• "Good evening. Here is your weather update for Jammu and Kashmir. The region experienced very cold conditions today with widespread snowfall.
• Temperatures remained low, with Srinagar at 6.5°C, while Gulmarg stayed below zero at -2.6°C. Heavy snowfall was recorded, with Gulmarg receiving 35 cm, followed by Kukernag and Pahalgam.
• Humidity levels were very high, reaching up to 100%, making the weather extremely cold and damp.
• Residents are advised to stay warm and be careful of icy roads."