NCERT Solutions for Class 7th Social Science Chapter 19 Infrastructure: Engine of India’s Development
Updated on 2026-09-19
About this chapter
Physical infrastructure is the “vast network of tangible structures built to keep our cities and villages functioning”. The chapter lists four families of it: transportation (roads, bridges, railways), utilities (electricity, water pipelines), communication networks (internet, telephone lines, telecom towers) and energy infrastructure (windmills, solar parks, oil and gas pipelines). The opening quotation from APJ Abdul Kalam sets the standard: a developed India is one where urban and rural areas have the same infrastructure. Infrastructure works as a chain, not as separate pieces. Rishabh’s journey from Delhi to Talegaon uses a bridge, a car park, a metro, a train, a smartphone, a bus, flyovers and an autorickshaw. Satish’s tomatoes need canals and electric pumps for irrigation, roads for
- Chapter opening
- Introduction
- After Rishabh’s journey and Satish’s tomatoes
- Opening of ‘Transportation Infrastructure’
- (c) Metro train systems
- (d) Air transport, with the map of airports (Fig. 7.18)
- After the account of J.C. Bose and his inventions
- Before ‘Collective Responsibility Towards Infrastructure’
- Collective Responsibility Towards Infrastructure
- The chapter in two points
Quick revision
| Term or fact | What it means | Where it appears in the chapter | Worth remembering |
|---|---|---|---|
| Physical infrastructure | The vast network of tangible structures built to keep cities and villages functioning | Page 170, Introduction | Four families: transport, utilities, communication, energy |
| Social infrastructure | Schools, colleges, training centres, hospitals, health centres, police and fire stations, courts, parks, libraries, community centres | THINK ABOUT IT, page 188 | Physical infrastructure carries things; social infrastructure builds people |
| National highways | Fast roads joining cities across states, built and maintained by the central government | Pages 173–175 | About 150,000 km (2025); NH44 is longest at 4,112 km |
| State highways | Roads connecting towns and districts within a state, built and maintained by state public works departments | Page 173 | Below them are the local roads that reach homes, fields and schools |
| Golden Quadrilateral | Highway network connecting Delhi, Mumbai, Chennai and Kolkata | DON’T MISS OUT, page 175 | Four cities, four corners of the country |
| Dhola Sadiya Bridge (Bhupen Hazarika Setu) | Bridge over the Lohit River joining Assam and Arunachal Pradesh | Page 175, Fig. 7.5 | 9.15 km, India’s second longest; cut travel time by 4 hours |
| Living root bridge (jingkieng jri) | A bridge grown from the roots of the Ficus elastica (Indian rubber tree), guided across streams with bamboo and palm trunks | Pages 175–176, Fig. 7.6 | Made by the Khāsi and Jaintia tribes; 15–30 m high; takes decades to mature |
| Indian Railways | Started by the British in 1853 to move raw materials to ports; today the world’s fourth-largest railway system | Pages 176–179 | Over 20 million passengers a day; about 1.21 million employees (2024) |
| Electrified railway network | Share of railway track that runs on electricity instead of coal or diesel | Fig. 7.8, page 177 | India 97% · China 75% · France 61% · Germany 55% · UK 38% (2024) |
| Length of railway track, 2024 | Country-wise comparison of total track length | Fig. 7.11, page 179 | USA 293,564 · China 150,000 · Russia 85,494 · India 69,181 · Canada 48,000 km |
| Metro train systems | Fast urban rail on underground and elevated tracks | Page 180 | 23 cities, over 1,000 km; Delhi Metro uses some solar power |
| Air transport | Fastest link between people and places; passenger flights and cargo flights | Pages 180–182 | 159 airports in 2025; about 376 million passengers in 2024–25 |
| Ports and shipping | Ships dock at ports where heavy goods are loaded and unloaded | Pages 183–184, Figs. 7.21–7.22 | Coastline about 11,100 km; 12 major and 217 minor ports; cargo up 50% in a decade |
| TEU | Twenty-foot Equivalent Units — a measure of container-ship capacity and port activity | Note under Fig. 7.21, page 183 | Generally 1 TEU = 33 cubic metres; these numbers need not be memorised |
| E-commerce | Buying or selling products and services on online platforms or over the internet | Margin note, page 185 | Lets a small seller reach buyers across the world |
| E-governance | Use of communication technologies by government to deliver services to citizens | Margin note, page 185 | Example: the DigiLocker app for Aadhaar card and driving licence |
| Patent | A right granted by the government or an institution to be the only person or company who can make, sell or use an invention for a certain number of years | Margin note, page 186 | J.C. Bose rarely patented his inventions |
| J.C. Bose (1858–1937) | Indian scientist who pioneered wireless transmission using microwaves in the millimetre range | DON’T MISS OUT, pages 186–187 | Calcutta experiment 1895; invented a new coherer; founded the Bose Institute in 1917 |
| Arthaśhāstra road rules | Kautilya’s text setting road widths by the traffic they carried, and penalties for damaging public works | Page 189 | Royal/countryside/port/village roads 16 m · forest and city roads 8 m · chariot roads 2.5 m |
| Collective responsibility | Public infrastructure belongs to everyone, so using it well and reporting damage is every citizen’s duty | Pages 188–190 | Report potholes and broken streetlights; do not deface walls or monuments |
Exercises
- Chapter opening — The Big Questions Page 169
- Introduction — In-text Questions Page 170
- After Rishabh’s journey and Satish’s tomatoes — THINK ABOUT IT Page 173
- Opening of ‘Transportation Infrastructure’ — In-text Question Page 173
- (c) Metro train systems — LET’S EXPLORE Page 180
- (d) Air transport, with the map of airports (Fig. 7.18) — In-text Question Page 181
- After Rani’s voice note travels from Madhya Pradesh to Tamil Nadu — THINK ABOUT IT Page 185
- After the account of J.C. Bose and his inventions — THINK ABOUT IT Page 187
- Before ‘Collective Responsibility Towards Infrastructure’ — THINK ABOUT IT Page 188
- Collective Responsibility Towards Infrastructure — LET’S EXPLORE Page 190
- The chapter in two points — Before we move on … Page 190
- End-of-chapter exercise — Questions and activities Page 191–192