NCERT Solutions for Class 7th Social Science Chapter 19 Chapter opening — The Big Questions

Book page 169 Updated on2026-09-19

Q1.

What is physical infrastructure, and how has it transformed over the years in India?

Answer

Physical infrastructure is the vast network of tangible structures built to keep our cities and villages functioning. “Tangible” means you can touch it — it is made of concrete, steel, cable and pipe, not of rules or ideas.

The chapter groups it into four families:

Family	What it includes (the book’s own examples)
Transportation systems	Roads, bridges, railways — and, as the chapter goes on, metros, airports and ports
Utilities	Electricity, water pipelines
Communication networks	Internet, telephone lines, telecom towers
Energy infrastructure	Windmills, solar parks, oil and gas pipelines

How it has transformed. The chapter tells this as a story of growth in every one of those families:

Roads. India now has the second-largest road network in the world, after the USA (2024). National highways run to about 150,000 km (2025), and NH44 alone stretches 4,112 km from Srinagar to Kanyakumari. Expressways and the Golden Quadrilateral — Delhi, Mumbai, Chennai, Kolkata — did not exist a few decades ago.
Bridges and tunnels. Where highways cannot go, bridges do. The Dhola Sadiya Bridge (9.15 km) now crosses the Lohit River all year, where earlier people depended on ferries that stopped in the floods.
Railways. Begun in 1853 by the British to carry cotton and tea to the ports, they are today the fourth-largest railway system in the world. Fig. 7.12 shows the machines changing: steam (F-734, 1895) → diesel (WDM-1, 1957) → electric (WAM-4, 1970) → Vande Bharat (2019). Fig. 7.8 shows 97 per cent of India’s network electrified in 2024 — the highest of the five countries compared.
Metros. From none at all to 23 cities and over 1,000 km of track.
Air and sea. 159 airports in 2025, about 376 million air passengers in 2024–25, and cargo handled at ports up by 50 per cent in the past decade.
Communication. Fig. 7.23 runs from runners and horse couriers to the telegraph, the telephone, radio, the internet and now 5G, cloud communication and AI-driven services. In 2025 India had 1,160 million wireless telephone subscribers.

Why it happens: each piece of infrastructure makes the next one worth building. A road is more useful once there is a market at the end of it; a market grows once trucks can reach it; cold storage becomes worth building once the trucks come regularly. That is why growth in infrastructure tends to speed up rather than stay steady.

Q2.

How has the expansion in infrastructure affected the quality of life for individuals and communities?

Answer

It has made everyday life faster, safer, cheaper and more connected — the chapter calls this “ease of living”. The clearest way to see it is through the two people the chapter follows.

Person	What infrastructure does for them	Life without it
Rishabh (Delhi → Talegaon, Nashik)	Bridge → car park → metro (skips the traffic) → train → bus over flyovers → autorickshaw to his door; a smartphone to call his mother and share his location	A two-day journey would take far longer, and no one at home would know where he was
Satish (tomato farmer, Maharashtra)	Canals and electric pumps for irrigation; good roads for the trucks; cold storage to keep the tomatoes fresh; the internet to learn about the best inputs and market prices	Crops watered by rain alone, tomatoes spoiling on the way, and no idea what price the mandi is paying

For communities the chapter names these gains:

Health and safety. Ambulances reach hospitals on local roads. After the Dhola Sadiya Bridge, people can reach hospitals or medicines faster, even during floods.
Livelihood. Farmers get their produce to market before it spoils. Indian Railways alone employs about 1.21 million people, plus indirect jobs in catering, vending and taxi services.
Learning. Students can use online classes, digital libraries and educational videos “even in remote areas”.
Emergencies. Mobile SMS alerts and apps warn people; cargo flights can reach mountains, deserts, forests and islands with aid.
Cost. Indian Railways is “one of the cheapest train services in the world”, and mobile calls have fallen from up to ₹17 per minute in the 1990s to among the world’s cheapest rates.
Cleaner air. Metros use electricity, some of it solar; electrified trains replace coal and diesel; cargo trains use 75–90 per cent less energy than road transport.

Did you know? The chapter is careful to say the work is not finished. It lists littering, stained buildings, writing on monuments, potholes, weak waste management and sewer systems as challenges that “still exist”, and asks for designs that suit children, the elderly and disabled persons.

Q3.

What is the role of infrastructure in the development and economic prosperity of the nation?

Answer

Infrastructure is what every other economic activity stands on. The chapter says it plainly: physical infrastructure “is the backbone of our nation — it makes life easier for people, communities, businesses, and enables government to function smoothly”, and Before we move on … repeats that quality infrastructure “is the backbone for all other economic activities taking place in a country”.

Its work can be listed under five heads:

Role	How the chapter shows it
Connects producers to markets	Roads, railways, airways and shipping “connect places of origin or manufacturing of goods and services to the nearest markets” — this is exactly Satish’s truck to the mandi
Carries trade, inside and outside India	India has had trade routes since ancient times; modern infrastructure “has taken this forward to boost trade, both within and outside the country”. The 11,100 km coastline links India to West Asia, Africa and Europe
Creates jobs	Direct jobs (engineers, ticket collectors, service staff) and indirect ones (catering, vending, taxis). Before we move on … lists “employment opportunities for people”
Reaches the places left out	Better infrastructure “supports tourism, connects remote areas, and helps during emergencies like floods or earthquakes”
Strengthens national security	It improves “access to all kinds of terrain for the defence forces”

Why it happens: goods and services only earn money when they reach someone willing to pay for them. Infrastructure lowers the cost and the time of that journey — for a farmer, a factory, a student or a doctor. Lower cost and less time mean more can be produced and sold, which is what prosperity is made of. This is why the chapter is titled the engine of India’s development: an engine does not carry the load itself, it moves everything else.

Tip: Link this back to Dr Kalam’s words on the opening page — “A developed India will be one where urban and rural areas have the same infrastructure — roads, power, water, and communication.” Development, in this chapter’s sense, is measured by whether a village gets what a city gets.

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