Class 9 SST Part 1 Chapter 3 Solutions – Atmosphere, Climate

Class 9 Social Science (SST) Part 1 Chapter 3 NCERT Solutions 2026-27: step-by-step answers of Atmosphere and Climate. Free, CBSE-aligned.

Looking for accurate and complete ncert class 9 social science chapter 3 solutions for the new CBSE curriculum (2026-27)? You are in the right place! In this guide, we provide step-by-step, direct, and easy-to-understand solutions for all exercise questions from Understanding Society: India and Beyond Class 9 SST Part 1 Chapter 3: Atmosphere and Climate. These answers are crafted specifically to help students write clean, exam-ready answers in their notebooks without extra confusion or lengthy fluff.

Question 1

What is atmosphere? Explain its composition with the help of a pie diagram.

Answer:

The atmosphere is a blanket of air surrounding the Earth, held by gravity. It is essential for life and protects us from harmful solar radiation.

Composition:

  • Nitrogen: 78%
  • Oxygen: 21%
  • Argon: 0.93%
  • Carbon Dioxide: 0.04%
  • Other gases: 0.03% (Neon, Helium, Krypton, etc.)
  • Water Vapour & Dust: Variable amounts (0.1% to 0.4%)

(Draw a pie chart showing Nitrogen as the largest slice, followed by Oxygen, and tiny slices for Argon, CO2, and Other gases).

Question 2

Draw a labelled diagram of the structure of atmosphere.

Answer:

(This is a drawing activity). Draw a tall vertical rectangle representing the atmosphere. Draw horizontal lines to separate the layers from bottom to top and label them:

  1. Troposphere (0-12 km)
  2. Stratosphere (12-50 km) - label Ozone Layer here.
  3. Mesosphere (50-80 km)
  4. Thermosphere (80-700 km)
  5. Exosphere (above 700 km)

Question 3

Which are the four main seasons of India?

Answer:

The Indian Meteorological Department (IMD) recognises four main seasons in India:

  1. Winter: December to early April.
  2. Summer or Pre-monsoon: April to June.
  3. Monsoon or Rainy: June to September.
  4. Post-monsoon or Retreating Monsoon: October to December.

Question 4

Why do you not feel the pressure of the atmosphere?

Answer:

We do not feel the atmospheric pressure because the air presses on us from all sides equally. Our bodies also exert a counter-pressure from within (internal pressure) that exactly balances the external atmospheric pressure, so we do not feel it.

Question 5

In which layer of the atmosphere do aeroplanes fly and why?

Answer:

Aeroplanes fly in the Stratosphere layer. This is because the stratosphere is free of clouds and other weather disturbances (like storms and turbulence), providing a smooth and stable flight path. Also, the air density is lower, which reduces drag and helps save fuel.

Question 6

Distinguish between the following: (a) The troposphere and stratosphere (b) The south-west monsoon and north-east monsoon

Answer:

(a) Troposphere vs Stratosphere:

  • Troposphere: Lowest layer (0-12 km). Temperature decreases with altitude. All weather phenomena (rain, fog, clouds) occur here.
  • Stratosphere: Above the troposphere (up to 50 km). Contains the ozone layer. Free of clouds and weather disturbances, ideal for jet flights.

(b) South-West Monsoon vs North-East Monsoon:

  • South-West Monsoon (Summer): Blows from sea to land (June to September). Brings heavy rainfall to most parts of India.
  • North-East Monsoon (Winter): Blows from land to sea (October to February). Cold and dry, but picks up moisture over the Bay of Bengal and brings rain to the eastern coast (Tamil Nadu, Andhra Pradesh).

Class 9 sst Part 1 solutions (All Chapters)
Ch 1 Ch 2 Ch 3 Ch 4 Ch 5 Ch 6 Ch 7 Ch 8 Ch 9
Class 9 sst Part 2 solutions (All Chapters)
Ch 1 Ch 2 Ch 3 Ch 4 Ch 5 Ch 6

Frequently Asked Questions (FAQs)

Q1: What is the difference between weather and climate?
Weather refers to the day-to-day conditions of the atmosphere (hot, cold, rainy), while climate is the average weather condition of a place over a long period (usually 30 years or more).
Q2: What is the mechanism of the Indian monsoon?
It is caused by the unequal heating of land and sea. In summer, the land heats up faster, creating low pressure, which draws in moist winds from the high-pressure Indian Ocean, bringing rain.

Based on latest NCERT class 9 book.