NCERT Solutions Exploring Society: India and Beyond Chapter 2 –42The chapter in four points — Before we move on ...

Book page 41 Updated on2026-09-05

Q1.

Temperature, humidity, precipitation, wind and atmospheric pressure together define the weather at a particular place.

Answer

These five are the elements of weather. No single one of them is the weather — the weather is the combination of all five at one place at one moment.

Element	What it is
Temperature	How hot or cold the atmosphere is
Precipitation	Any form of water — rain, snow, sleet or hail — that falls from the sky
Atmospheric pressure	The weight of the air above us, felt on the Earth's surface
Wind	The movement of air, including its speed and direction
Humidity	The amount of water vapour in the air

Why all five are needed: 29°C tells you almost nothing on its own. Add 84% humidity and you know it will feel sticky and oppressive; add a falling barometer and you know a storm may be building; add a strong wind and you know the washing will still dry. Weather is a description of the atmosphere, and it takes all five numbers to make that description complete.

Q2.

The condition of these elements is measured using special instruments. Data collected from these help us to monitor and predict the weather.

Answer

Each element has its instrument, and the instruments are brought together at a weather station:

Thermometer → temperature (°C)
Rain gauge → precipitation (mm)
Barometer → atmospheric pressure (mb)
Wind vane and anemometer → wind direction and speed (km/h)
Hygrometer → humidity (% relative humidity)

Readings are taken at regular intervals, which is what makes mapping and forecasting possible. An Automated Weather Station (AWS) does the same job with sensors alone, and is used in agriculture, aviation, navigation and environmental monitoring, providing accurate and timely information without human intervention.

Why the record matters more than any one reading: A single reading describes a moment. Only a long series of readings, studied with scientific methods, reveals the patterns from which meteorologists can predict what the weather will do next.

Q3.

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.

Answer

All five elements are always present, but at any given moment one of them decides everything — and that is the one the forecast leads with.

Situation	Dominant element	Why it takes over
July, in most of India	Precipitation	The monsoon is in full swing; the day's news is how much rain fell and where
May, and again in December	Temperature	Peak summer heat and peak winter cold — heat waves and cold waves
A cyclone moving in	Atmospheric pressure	A deep fall in pressure is what makes and steers the cyclone
A loo blowing in north India	Wind	Strong, hot and dusty winds make even the shade unbearable
A forest fire spreading	Wind	Wind speed and direction decide how fast and where the fire runs

Tip: The loo is a good example to remember, because it is both a wind and a heat event — it is dangerous precisely because hot air is being moved fast over your skin, so sweating no longer cools you.

Q4.

Weather is closely linked to climate. We will discuss this in the next chapter.

Answer

The link is time. Weather is the state of the atmosphere now, at one place. Climate is the pattern that the weather of a place shows when it is averaged over many years.

	Weather	Climate
Period	A moment, a day, a week	Decades — usually 30 years or more
Changes	Can change within hours	Changes very slowly
Example	“It is 32°C and raining in Kochi this afternoon.”	“Kochi is hot and humid, with heavy rain from June to September.”
How we know it	Today's instrument readings	Years of stored readings, averaged

Why the chapters are in this order: Climate is built out of weather records. You cannot describe the climate of a place until someone has measured its weather, day after day, for many years — which is exactly what this chapter has been about.

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