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Understanding the Weather – Class 7 Social Science notes, important questions and MCQs

NCERT Class 7 Social Science, chapter 2. Notes, key terms, important questions with answers and MCQs.

Chapter overview

Weather is the day-to-day condition of the atmosphere at a place, while climate is the average weather over a long period. Weather is described by temperature, air pressure, humidity, wind and rainfall, which are measured with special instruments at weather stations.

Weather and climate

Weather can change within hours; climate describes the usual pattern over about 30 years or more.
The India Meteorological Department (IMD), set up in 1875, observes the weather and issues forecasts and warnings.

Elements and instruments

Temperature: thermometer; maximum–minimum thermometers record the highest and lowest temperature of a day.
Air pressure: barometer; low pressure often brings clouds and rain, high pressure brings clear skies.
Humidity (moisture in the air): hygrometer; wind speed: anemometer; wind direction: wind vane.
Rainfall: rain gauge, measured in millimetres or centimetres.

Why weather matters

Farmers, fishers, pilots and travellers depend on forecasts.
Early warnings of cyclones, heat waves and heavy rain save lives.

Key terms

Weather: the condition of the atmosphere at a place for a short time
Climate: the average weather of a place over a long period
Humidity: the amount of water vapour in the air
Rain gauge: an instrument used to measure the amount of rainfall

Important questions with answers

What is the difference between weather and climate?2 marks

Weather is the condition of the atmosphere at a place for a short time, such as a day, and it can change within hours. Climate is the average weather of a place over a long period, usually about 30 years or more.

Name the elements of weather and the instruments used to measure them.3 marks

Temperature is measured with a thermometer, air pressure with a barometer, humidity with a hygrometer, wind speed with an anemometer, wind direction with a wind vane and rainfall with a rain gauge.

Why is weather forecasting important? How are forecasts made?5 marks

Weather forecasting helps farmers decide when to sow, irrigate and harvest; helps fishers decide whether it is safe to go to sea; and helps airlines, ships and travellers plan safely. Early warnings of cyclones, floods, heat waves and cold waves allow people to move to safety, which saves many lives and reduces losses. Forecasts are made by recording temperature, pressure, humidity, wind and rainfall at many weather stations, using satellites and radars to track clouds and storms, and using computers to study how the atmosphere is changing. In India, the India Meteorological Department, set up in 1875, issues forecasts and warnings.

Quick revision

Weather = short-term; climate = long-term average.
Thermometer, barometer, hygrometer, anemometer, wind vane, rain gauge.
IMD set up in 1875.
Forecasts and warnings save lives.

Exam tips

Make a two-column table of weather elements and the instruments that measure them.
Remember: 'weather is your mood, climate is your personality'.

Practice MCQs

Air pressure is measured with a
1. thermometer
2. hygrometer
3. rain gauge
4. barometer
Show answer
Answer: (d) barometer. A barometer records air pressure.
The average weather of a place over many years is its
1. climate
2. weather
3. season
4. forecast
Show answer
Answer: (a) climate. Climate is long-term.
Rainfall is measured with a
1. wind vane
2. barometer
3. anemometer
4. rain gauge
Show answer
Answer: (d) rain gauge. It collects rainwater for measurement.
An anemometer measures
1. wind direction
2. humidity
3. wind speed
4. temperature
Show answer
Answer: (c) wind speed. Its cups spin faster in strong wind.
The amount of water vapour in the air is called
1. pressure
2. humidity
3. precipitation
4. temperature
Show answer
Answer: (b) humidity. It is measured with a hygrometer.
The India Meteorological Department was set up in
1. 1857
2. 1875
3. 1947
4. 1950
Show answer
Answer: (b) 1875. It issues weather forecasts.
Low air pressure over a region usually brings
1. clouds and rain
2. clear skies
3. snow only
4. no wind
Show answer
Answer: (a) clouds and rain. Rising air cools and forms clouds.
Which statement shows climate rather than weather
1. It is raining in Bhubaneswar today
2. It is hot this afternoon
3. There was a storm last night
4. Kerala receives heavy rain every year in June–September
Show answer
Answer: (d) Kerala receives heavy rain every year in June–September. It describes the usual long-term pattern.

All chapters of Class 7 Social Science

Written by Kundali IQ from standard, well-established facts to help with revision. This is not an official NCERT publication; always read your textbook too.