NCERT Solutions for Class 9th Social Science Chapter 2 Shaping of the Earth’s Surface
Updated on 2026-09-08
About this chapter
The Earth has three main layers — crust , mantle and core . The crust together with the upper mantle makes the rigid lithosphere (about 100 km thick in Fig. 2.1); below it lies the hot, partly molten asthenosphere (about 200 km), which is what lets the plates move at all. The lithosphere is broken into tectonic plates — continental, oceanic and mixed — that creep along at a few centimetres a year. Fig. 2.3 names seven major plates: Pacific, Eurasian, African, North American, South American, Indo-Australian and Antarctic. Plates move because of convection currents in the mantle: heated material rises, cooler material sinks, and the circulating mantle pushes and pulls the plates. Fig. 2.2 splits the total interior heat flow between crust (24%), upper mantle (22%), lower mantle (32%) and core
- Chapter opening
- The Ring of Fire in Fig. 2.4
- Does India have a risk of earthquakes? (Fig. 2.5)
- The photograph in Fig. 2.6
- Erosion caused by (a) water and (b) wind
- The Sundarbans delta (Fig. 2.13)
- The Chamoli flood of February 2021 (Fig. 2.20)
- Landforms around your school or home
- Completing the disaster exercises on pages 33–36
- The chapter's recap points, expanded
Exercises
- Chapter opening — The Big Questions Page 13
- Fig. 2.3, world map showing major plates and their direction of movement — LET'S MAP Page 16
- Comparing the plate map (Fig. 2.3) with the earthquake and volcano map (Fig. 2.4) — LET'S EXPLORE Page 16
- The Ring of Fire in Fig. 2.4 — LET'S EXPLORE Page 17
- Does India have a risk of earthquakes? (Fig. 2.5) — LET'S EXPLORE Page 17
- The photograph in Fig. 2.6 — LET'S EXPLORE Page 18
- Erosion caused by (a) water and (b) wind — LET'S EXPLORE Page 21
- The Sundarbans delta (Fig. 2.13) — LET'S EXPLORE Page 25
- The Chamoli flood of February 2021 (Fig. 2.20) — THINK ABOUT IT Page 29
- Landforms around your school or home — LET'S EXPLORE Page 32
- Completing the disaster exercises on pages 33–36 — LET'S EXPLORE Page 32
- The chapter's recap points, expanded — Before we move on … Page 37
- End-of-chapter exercise — Questions and activities Page 37–38