NCERT Solutions Class 7 Social Science Chapter 19 Infrastructure Engine of India s Development

F R E E S T U D Y M AT E R I A L F O R E V E R Y S T U D E N T

CLASS 7 · SOCIAL SCIENCE

NCERT Solutions

Chapter 19: Infrastructure:
Engine of India’s Development

NCERT Textbook — Exploring Society: India And Beyond (Part I)

BOOK PAGES SECTIONS QUESTIONS MEDIUM

Part II, 169 – 192 12 29 English

Solutions, notes, sample papers & more at 37 pages

Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

CLASS 7 · SOCIAL SCIENCE · EXPLORING SOCIETY: INDIA AND BEYOND (PART I)

NCERT Solutions — Chapter 19: Infrastructure: Engine
of India’s Development
Complete NCERT Solutions for Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s
Development — the third chapter of Theme E, Economic Life Around Us, in Exploring Society: India and Beyond
(Grade 7, Part 2). Every question the chapter asks is answered here: the three Big Questions, all four THINK
ABOUT IT boxes, both LET’S EXPLORE boxes, Before we move on …, the seven end-of-chapter Questions
and activities, and every question asked in the running text on pages 170, 173 and 181. The three DON’T
MISS OUT boxes carry no question, so their facts are folded into the answers and into the revision table
below. All figures — Fig. 7.8, Fig. 7.11, Fig. 7.21 and the two maps — have been read off the printed pages,
and every number worked out again.

TEXTBOOK BOOK PAGES

Exploring Society: India and Beyond (Part I) (Class Part II, 169 – 192
7)

SECTIONS QUESTIONS

12 29

MEDIUM

English

The Big Questions — Page 169
Chapter opening — Theme E, Economic Life Around Us

THE BIG QUESTIONS

Q1 What is physical infrastructure, and how has it transformed over the years in India?

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:

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

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.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q2 How has the expansion in infrastructure affected the quality of life for individuals
and communities?

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 Bridge → car park → metro (skips the traffic) → train A two-day journey would take
(Delhi → → bus over flyovers → autorickshaw to his door; a far longer, and no one at home
Talegaon, smartphone to call his mother and share his location would know where he was
Nashik)

Satish Canals and electric pumps for irrigation; good roads Crops watered by rain alone,
(tomato farmer, for the trucks; cold storage to keep the tomatoes fresh; tomatoes spoiling on the way,
Maharashtra) the internet to learn about the best inputs and market and no idea what price the
prices 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.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

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What is the role of infrastructure in the development and economic prosperity of
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Infrastructure is what every other economic activity stands on. The chapter says it plainly:

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communities, businesses, and enables government to function smoothly”, and Before we move

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can be produced and sold, which is what prosperity is made of. This is why the

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Tip: Link this back to Dr Kalam’s words on the opening page — “A developed India

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power, water, and communication.” Development, in this chapter’s sense, is

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

In-text Questions — Page 170
Introduction — the morning with no infrastructure

Q1 Imagine you wake up one morning, ready for school. But when you step outside,
there are no roads. The buses are gone. No one’s mobile phone has any signal. The
lights won’t turn on, the internet is gone, and the tap is running dry! How would
you reach school?

Mostly, I could not — and if I did, it would take most of the day. With no roads and no buses,
the only ways left are walking or cycling over open ground, and only if the school is close
enough.
Work through what has failed, one piece at a time:

MISSING PIECE WHAT IT STOPS

No roads No car, autorickshaw, cycle-rickshaw or truck can move; even an ambulance is stuck

No buses Children from far-off villages and colonies cannot come at all

No mobile signal I cannot tell the school I am late, and my family cannot check that I am safe

No electricity No lights, no fans, no computer lab; a school that starts before sunrise cannot begin

Why it happens: reaching school is not one service but a chain of them — a surface
to travel on, a vehicle, fuel or electricity for that vehicle, and a signal to coordinate. A
chain is only as strong as its weakest link, which is the point the whole Introduction
is making.

Q2 How would groceries, and stationery reach your nearest market and your home?

They would not reach in any useful quantity. Almost everything in a shop has already
travelled — by truck on a highway, by goods train, by ship into a port, or by all three.
Follow one item, a packet of rice:

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

field → road → mandi

mandi → goods train or truck → wholesaler’s warehouse

warehouse → road → your neighbourhood shop
shop → your street → home

Break any arrow and the packet stops. Without roads, a shopkeeper could sell only what is
grown or made within walking distance. Perishable goods — milk, vegetables, fruit — would be
worst hit, because they cannot wait. The chapter shows the same idea from the other end:
Satish’s tomatoes reach the city because “good roads helped trucks carry his tomatoes to the
city, cold storage kept them fresh”.

Check it yourself: Look at five things in your school bag and ask where each was
made. Almost none will have been made in your own street — every one of them
arrived on infrastructure.

Q3 How would you access utilities like electricity and water?

Only by carrying water by hand and doing without electric power. Utilities do not arrive on
their own; they arrive through built networks.

Electricity is generated far away — at a dam like Bhakra Nangal, a wind farm like
Muppandal, or a solar project like the one at Cochin International Airport (Fig. 7.2) — and
then carried over transmission lines to your switchboard. No lines, no light, no pump, no
mobile tower.
Water reaches the tap through pipelines from a reservoir or treatment plant. Without them,
a household must fetch water from a well, a handpump, a pond or a river, carry it home, and
boil or filter it before drinking.

Why it happens: the chapter calls electricity and water pipelines utilities, one of the
four families of physical infrastructure. Their special feature is that they are
continuous — a road can be used now and then, but a water pipe or a power line has
to work every hour of every day, which is why maintaining them matters as much as
building them.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Tip: Notice how the losses spread. No electricity also means no mobile tower, so “no
signal” in this imaginary morning is really a second effect of the first failure.
Infrastructure failures rarely stay alone.

THINK ABOUT IT — Page 173
After Rishabh’s journey and Satish’s tomatoes

THINK ABOUT IT

Q1 What might happen to Satish’s efforts if any part of the infrastructure is missing?

His hard work would be wasted at whichever link fails — the crop would either not grow, not
travel, not stay fresh, or not fetch a fair price. The chapter names four supports behind his “red
and juicy tomatoes”; take each away in turn:

MISSING PIECE WHAT HAPPENS TO SATISH

Canals and electric Irrigation fails. He must depend on rain alone, so a weak monsoon means a small,
water pumps poor-quality crop — or none

Good roads Trucks cannot reach the field, or take too long. Tomatoes bruise and rot on the way;
some never leave the village

Cold storage He must sell everything the same day at whatever price he is offered, because the crop
will not keep

Internet He does not know about better inputs, and does not know today’s mandi prices — so
he has no way of judging whether the price offered is fair

Why it happens: the chapter says physical infrastructure is “connected like pieces of
a puzzle”. The pieces are not spares for one another — a good road cannot water a
field, and cold storage cannot tell you a price. So the whole system delivers only as
much as its weakest piece allows.

Tip: Notice the order of the losses. The first two pieces decide whether he has a crop
at all; the last two decide how much he earns from it. Both matter to a farming
household.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q2 What happens when a new highway is built near a village? How does it impact the
lives of the people living nearby?

The village stops being far away. A highway shortens the time between the village and the
nearest town, and that single change works through daily life in many ways.
What usually improves

Getting produce out. Trucks arrive, and crops, milk and handicrafts reach bigger markets
while still fresh — the same gain Satish gets.
Getting services in. Hospitals, colleges and government offices become reachable; an
ambulance or a fire engine can come.
Work. Building and maintaining the road is work in itself; afterwards, dhabas, repair shops,
petrol pumps, cold storages and small workshops tend to come up along it. The chapter
makes exactly this point for railways: “new settlements emerged near stations”.
Choice. Goods from outside arrive, so prices in the village shop face competition; young
people can study or work in the town and come home the same day.

What has to be watched

Farmland may be taken for the road, so the households that lose it need proper
compensation.
Fast traffic near a village is dangerous for children and cattle, so crossings, footpaths, speed
control and, as the chapter notes elsewhere, even alarm systems where animals cross are
needed.
Noise, dust and vehicle exhaust rise; the chapter’s section on sustainable infrastructure asks
for exactly this to be planned for.

Why it happens: a highway does not simply pass by a village — it changes the cost
of travel for everyone near it. When travel becomes cheap and quick, activities that
were impossible before become worth doing, and new ones appear along the road.
That is why the effects are far bigger than “a road was built”.

Q3 Imagine if there were no internet or phone services. How would this affect people’s
ability to work or learn?

Work and learning would slow down and shrink to whatever can be done face to face. The
chapter lists what communication infrastructure makes possible; remove it, and each of those
goes.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

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AREA WHAT WE WOULD LOSE (THE CHAPTER’S OWN EXAMPLES)

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Learning Online classes, digital libraries and educational videos — the chapter stresses

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Farming Satish could not check input advice or market prices before selling

Why it happens: a phone call or a message replaces a journey. Every message that
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Did you know? The chapter reminds us how new all this is. In the 1990s a mobile

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In-text Question — Page 173
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an airport, a jetty), because that is what the chapter is asking you to notice.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

DISTANCE COMMON MODES INFRASTRUCTURE IT DEPENDS
ON

Within the On foot, cycle, cycle-rickshaw Local roads, footpaths, street lighting
neighbourhood

Across the town or Bus, autorickshaw, two-wheeler, car, metro City roads, flyovers, bus stands, metro
city lines and stations

To another town or State transport bus, shared taxi, train State highways, railway lines and
district stations

To another state Train, long-distance bus, car on a national National highways and expressways,
highway or expressway, sometimes a flight railway network, airports

Sample answer: “I walk about 10 minutes to school on our colony road. My mother
takes an autorickshaw to the market, about 3 km away, on the main road. My father
goes to his office 14 km away by bus, crossing a flyover on the way. Once a year we
visit my grandparents 600 km away — we take a night train, and reach the railway
station by autorickshaw. Last year my uncle came from Bengaluru by flight, and we
brought him home from the airport by car. So in one year our family used a footpath,
a colony road, a city road, a flyover, a railway line, an airport and a national highway.”

Why it matters: writing the list out shows that no single mode is enough. Even a
flight ends with a road journey. This is the “pieces of a puzzle” idea the chapter used
for Satish, seen now in your own week.

LET’S EXPLORE — Page 180
Section (c) Metro train systems

LET’S EXPLORE

Q1 Have you or your family members ever taken a train or a metro? What sort of
economic activities did you see around the stations? Share the experience with your
classmates.

This is a look-and-report activity, so the answer must come from a station you have
actually seen — or from someone in your family who has. What the question is really testing is
whether you can spot the economic life that grows around a piece of infrastructure.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Method. Stand outside the station (or recall your last visit) and list what people are buying,
selling or being paid for, in three rings:

RING WHAT YOU WILL USUALLY SEE WHO EARNS FROM IT

Inside the Ticket counters, food stalls and IRCTC vending units (Fig. 7.9), Railway or metro staff,
station book and magazine stalls, water and juice sellers, porters, licensed vendors, porters
cleaning and security staff

Just Autorickshaws, taxis, app-based cabs, cycle stands, parking lots, Drivers, cart owners,
outside tea and snack carts, fruit sellers, mobile-recharge and photocopy small shopkeepers
shops

The wider Hotels and lodges, luggage and footwear shops, coaching centres, Shop owners, their
area godowns and courier offices, wholesale shops that use the station workers, transporters
for freight

Sample answer: “Last Diwali we took a train from our town to my aunt’s city. On the
platform there was an IRCTC food stall, a tea vendor with a kettle, a bookstall and
two porters in red shirts. Outside the station about fifteen autorickshaws waited in a
line, with a fruit cart and a chai stall beside them. Across the road were three small
hotels and a shop selling suitcases. On the way back we used the metro. The metro
station itself had only a ticket counter and a small coffee kiosk inside — the rules
there are stricter — but at the exit there were cycle stands, app-cab pick-up points
and a row of shops in the mall next door. I noticed that the busier the station, the
more people earned a living around it.”

Why it happens: a station gathers a crowd at fixed times every day. Wherever
people gather with a little time to spare and a journey ahead of them, selling
becomes worthwhile — food, transport, storage, a place to stay. This is what the
chapter means when it says that as the railway network expanded, “trade grew,
major markets developed, and new settlements emerged near stations”, and that
railways create “many indirect jobs like catering, vending, and taxi services”.

In-text Question — Page 181

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Section (d) Air transport, with the map of airports (Fig. 7.18)

Q1 In 2025, India has 159 airports. Look at some of the international and domestic
airports in the map Fig. 7.18. Which airport is closest to your home?

You must answer this from the map in your own book, using your own location — no single
answer fits every reader. Here is how to find it reliably.
Method.

1. Find your own state on the map in Fig. 7.18.
2. Look for the numbered markers (international airports, 1–11) and lettered markers (national
airports, A–N) in and around that state.
3. Match each marker with the printed list below the map.
4. Of those, pick the one nearest to your town or district — use the map’s scale, or simply the
distance you would actually travel by road.

The map’s own lists, to check your answer against:

INTERNATIONAL AIRPORTS (1–11) NATIONAL AIRPORTS (A–N)

1. Chhatrapati Shivaji Maharaj International Airport, Mumbai, A. Darbhanga Airport, Darbhanga, Bihar
Maharashtra B. Dibrugarh Airport, Dibrugarh, Assam
2. Chennai International Airport, Chennai, Tamil Nadu C. Dimapur Airport, Dimapur, Nagaland
3. Dabolim Airport (Goa International Airport), Goa D. Diu Airport, Dadra and Nagar Haveli,
4. Indira Gandhi International Airport, Delhi Daman and Diu
5. Jaipur International Airport, Jaipur, Rajasthan E. Kandla Airport, Anjar, Gujarat
6. Kempegowda International Airport, Bengaluru, Karnataka F. Kushok Bakula Rimpochee Airport, Leh
7. Navi Mumbai International Airport, Navi Mumbai, G. Ludhiana Airport, Ludhiana, Punjab
Maharashtra H. Maharana Pratap Airport, Udaipur,
8. Netaji Subhash Chandra Bose International Airport, Kolkata, Rajasthan
West Bengal I. Pakyong Airport, Pakyong, Sikkim
9. Noida International Airport, Jewar, Uttar Pradesh J. Pantnagar Airport, Pantnagar, Uttarakhand
10. Rajiv Gandhi International Airport, Hyderabad, Telangana K. Pathankot Airport, Pathankot, Punjab
11. Sardar Vallabhbhai Patel International Airport, Ahmedabad, L. Puducherry Airport, Puducherry
Gujarat M. Swami Vivekananda Airport, Raipur,
Chhattisgarh
N. Tezu Airport, Tezu, Arunachal Pradesh

Sample answer: “I live in Udaipur, Rajasthan. On the map, marker H falls on my own
city — Maharana Pratap Airport, Udaipur. So the airport closest to my home is a
national airport, and the nearest international airport is number 5, Jaipur
International Airport, about 400 km away by road. If I had to fly abroad, I would first
travel to Jaipur or Ahmedabad.”

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Why it matters: the map shows that international airports cluster around big cities,
while national airports fill in the gaps — Leh in the mountains, Pakyong in Sikkim,
Tezu in Arunachal Pradesh, Diu on the coast. That is the map’s real lesson: air
transport is used to reach exactly the “difficult terrains like high mountains, deserts,
dense forests, and long oceanic stretches” the text names.

THINK ABOUT IT — Page 185
After Rani’s voice note travels from Madhya Pradesh to Tamil Nadu

THINK ABOUT IT

Q1 Which parts of this process do you think are easiest to see in real life, and which are
completely invisible?

Only the two ends and the tower are easy to see; almost everything in the middle is
hidden. Sort the journey the chapter describes into what your eyes can reach and what they
cannot.

STAGE OF RANI’S CAN YOU WHY
VOICE NOTE SEE IT?

The two phones — tap, Easily seen They are in our hands every day
record, send

Electricity powering the Partly seen You can see the tower and the power lines going to it,
mobile tower but not the current flowing

The mobile tower near her Easily seen Tall lattice masts stand above rooftops and fields
village

Fibre cables buried under Invisible Underground; you notice them only when a road is dug
fields and roads up and a warning marker appears

Transmission to satellites in Invisible Both the signal and the satellite are far beyond sight
space

Giant servers in distant cities Invisible Data centres are ordinary-looking buildings, usually far
from where we live

The message arriving on the Easily seen The visible end of the whole chain
cousin’s phone

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THINK ABOUT IT — Page 187
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After the account of J.C. Bose and his inventions

THINK ABOUT IT
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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Huge numbers of users. By 2025 India had 1,160 million wireless telephone subscribers
and nearly 900 million internet connections. In the 1990s a mobile phone was a rare object;
today the same network is shared by more than a hundred crore connections.
The infrastructure was actually built. The chapter lists what is behind a call — cables,
wireless devices, towers, satellites and data centres. Once fibre had been laid and towers put
up across the country, each extra call added very little new cost.
The technology kept improving. Fig. 7.23 ends with 5G, cloud communication and AI-
driven chat and voice services. Newer systems carry far more calls and data over the same
equipment.
Competition between service providers. When several companies offer the same service,
each must attract customers with lower rates — and the practice of charging for incoming
calls disappeared altogether.

Cost of the network is mostly fixed; the number of users is very large

Cost carried by each user = total cost ÷ number of users

More users → smaller share each → lower price per minute

Why it happens: this is the same idea as a village bus. Running the bus costs about
the same whether it carries five passengers or fifty — so the fare per passenger can
fall sharply once the bus fills up. Communication networks work the same way, only
on a national scale.

Q2 In 2025, there are 1,160 million wireless telephone subscribers and nearly 900
million internet connections in India.

Read these two numbers together — they say that almost everyone is now reachable, but
not everyone is yet online. The box gives them to think about, so let us work them out.

Wireless telephone subscribers = 1,160 million = 116 crore

Internet connections ≈ 900 million = 90 crore

Difference = 1,160 − 900 = 260 million ≈ 26 crore

Internet connections as a share of subscribers = 900 ÷ 1,160 ≈ 0.776 = about 78 per cent

What this tells us

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

India’s communication infrastructure — towers, fibre cables, satellites, data centres — is
now reaching almost the whole country. Nothing on this scale existed when a call cost ₹17 a
minute.
About four out of every five wireless connections also carry internet. So a phone in India
today is usually a doorway to online classes, digital libraries, e-commerce and e-governance,
not only to voice calls.
The gap of roughly 26 crore connections is the work still left. That is the gap Dr Kalam’s
opening quotation is about — a developed India is one where rural areas have the same
communication infrastructure as urban ones.

Tip: A “subscriber” or “connection” is not the same as a person. One person may hold
two SIM cards, and one home connection may be shared by a whole family. So use
these numbers to show the scale of the network, not to count people.

Q3 Ask your family or people in the neighbourhood how they sent long-distance
messages before mobile phones were introduced. What has been their experience
of using the first telephone or mobile phone?

This is an interview activity, so the answer has to be collected, not looked up. Its aim is to
turn Fig. 7.23’s timeline into living memory.
Method. Choose two or three people of different ages — a grandparent, a parent or neighbour
in their forties, and someone in their twenties. Ask the same questions to each, write the
answers in their own words, and note the person’s name and roughly which years they are
describing.
Questions worth asking

1. Before mobile phones, how did you send news to someone in another city or village? How
many days did it take?
2. Did you use letters, postcards, inland letters, telegrams, or a trunk call from a post office or
PCO?
3. What did it cost, and did you have to wait in a queue or book the call in advance?
4. What was the first telephone or mobile phone you used, and in which year? How did it feel?
5. What is the biggest difference you notice today?

What a good answer must contain: at least two named people, the method they used, a sense
of time taken and cost, and one sentence in their own words. Finish with your own comparison to
how you send a message today.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Sample answer: “I asked my grandmother, my father and my elder cousin.
My grandmother (about the 1970s): ‘We wrote inland letters. A letter to my brother
in Chennai took six or seven days, and his reply took another week — so one
exchange took a fortnight. For very urgent news we sent a telegram, and everyone
in the house grew anxious when a telegram arrived, because it usually meant bad
news.’
My father (about the 1990s): ‘There was one PCO in our market with a yellow
board. I would stand in line, and on Sundays the rate was lower, so the queue was
longest then. When we got our first mobile phone in 2001 it was a heavy Nokia, and
we spoke fast because incoming calls were also charged.’
My cousin (2010s): ‘I have never posted a letter. I send voice notes and video calls.’
So in three generations one message has gone from a fortnight to a few seconds
— exactly the change Fig. 7.23 shows from couriers and the telegraph to 5G and
cloud communication.”

THINK ABOUT IT — Page 188
Before ‘Collective Responsibility Towards Infrastructure’

THINK ABOUT IT

Q1 Do you see other types of infrastructure around you like schools, colleges, training
centres, hospitals, health centres, police stations, fire stations, courts, parks,
libraries, community centres and so on? This is known as social infrastructure. How
do you think it supports the wellbeing and development of communities and
society?

Yes — and this is social infrastructure: the buildings and services that develop people,
while physical infrastructure moves goods and people. Almost every locality has some of it.
Around my own school there is a primary health centre, a police station, a public library and a
park.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

SOCIAL WHAT IT DOES FOR THE COMMUNITY
INFRASTRUCTURE

Schools, colleges, training Give children literacy and skills, so they can take up better work later; training
centres centres let adults learn a trade

Hospitals and health centres Treat illness, give vaccinations and safe deliveries, so fewer working days and
school days are lost

Police and fire stations Keep people and property safe; a family that feels safe can work, study and
travel freely

Courts Settle disputes by law instead of by force, so agreements and property are secure

Parks and community centres Give space for play, exercise, festivals and meetings — this is where a
neighbourhood becomes a community

Libraries Put books and information within reach of those who cannot buy them

Why it happens: physical infrastructure improves the conditions people live in; social
infrastructure improves the people themselves — their health, learning, safety and
sense of belonging. The two need each other. A hospital is of little use if no road
reaches it, and a fine highway means little to a child who has no school to travel to.
Together they are what the chapter means by development.

Try this: Draw a rough map of one kilometre around your home. Mark every piece of
physical infrastructure in one colour and every piece of social infrastructure in
another. The colour that is missing tells you what your locality needs next.

LET’S EXPLORE — Page 190
Collective Responsibility Towards Infrastructure

LET’S EXPLORE

Q1 Create a ‘Community Responsibility Pact’ on the board or as a poster. Come up with
ideas on how individuals can develop a sense of responsibility towards public
infrastructure.

A pact works only if every line is something a Class 7 student can actually do. So write short
promises in the first person, group them, and let the whole class sign at the bottom.

Page 18 of 37

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Method. Divide the board into four columns — Keep it clean · Use it properly · Report damage · Tell
co m
others. Let each group fill one column with three or four promises. Then copy the best on to
e m.
m l as
.co g
chart paper with a title, a border and one drawing, and put it up where the class can see it every

m a
se
day.

g l a
aSample answer — OUR COMMUNITY RESPONSIBILITY PACT

co m
Because roads, taps, buses, parks and school buildings belong to all of us, we
promise:
e m . ag
g l as
a
1. Keep it clean. We will use the dustbin, never litter on the road or in the park, and
never spit or write on walls, buses, benches or monuments.

c o m
2. Use it properly. We will close taps after use, switch off lights and fans when we
leave a room, use the footpath and the zebra crossing, and stand m .
s e in a queue at

. com counter.
the ticket
a gla
m not damage. We will not break streetlights, tear posters, pull out plants, or
ase
3. Do

agl scratch names on desks and station walls.

s
4. Report damage. If we see a pothole, an open manhole, a leaking pipe, a broken
m a
.co agl
streetlight or an overflowing drain, we will tell a teacher, an elder, or the

se m
a
Panchayat or municipal office — as the chapter says, citizens should “report any

ag l
damage to the authorities”.
5. Save water and power. We will report a leaking public tap the same day, because
water wasted is water somebody else did not get.
. c om
s em and one
6. Tell others. Each of us will explain this pact to one person at home
m a
.friend gl
co outside school, and we will thank the sweepers,aelectricians and repair

as em workers who look after our locality.
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Signed by all students of Class VII, on ____________.

se m
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m . a
ase
Why it happens: the chapter’s point is that damage to public infrastructure “reduces

a gl
ease of living for people and becomes a burden for every citizen”. Nobody sends a
private bill for a broken streetlight — the cost is paid out of public money that could
have built something new. That is exactly why looking after it is called a collective
co m
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e
responsibility.
m l as
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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q2 Can you think of ways in which infrastructure can become more sustainable around
you? For example, what changes would you make to your school to make it more
eco-friendly?

Yes — sustainable infrastructure means using cleaner energy and environment-friendly
materials so that pollution and harm to biodiversity are kept to a minimum, which is how
the chapter itself defines the goal. The book’s own example is solar panels on buildings to cut
emissions.
Changes I would make to my school

AREA CHANGE WHAT IT SAVES

Energy Solar panels on the roof; LED lights and Electricity, and the emissions from
ceiling fans; large windows so classrooms need producing it
no light by day

Water Rainwater harvesting from the roof into a Groundwater; a single dripping tap can
recharge pit; taps that shut on their own; a waste hundreds of litres in a week
plumber called the same day a tap leaks

Waste Separate green and blue bins; a compost pit Landfill space; the compost feeds the school
for leaves and canteen waste; no single-use garden
plastic in the canteen

Grounds More trees for shade, a small kitchen garden, Heat, dust and rainwater run-off; birds and
permeable paving instead of full concrete insects get a place

Travel A cycle stand, safe walking paths to the gate, Fuel and traffic at the school gate
and a shared school bus rather than many
separate vehicles

Access for A ramp beside the steps, a handrail, and one Nothing — it adds: the chapter asks that
all accessible toilet design consider “the needs of children, the
elderly and disabled persons”

Beyond the school, the same idea applies to the locality: solar street lights, covered drains, a
working segregation system for waste, cycle tracks, and tree lines along roads.

Why it happens: infrastructure lasts for decades, so a choice made once — where a
window goes, whether a roof carries solar panels, whether a ramp is built — keeps
saving or wasting resources every single day for the whole life of the building. That
is why it is far cheaper to design sustainably than to repair later.

Page 20 of 37

Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q3 Write down a list of five problems you have observed and their possible solutions on
a sheet and discuss in class.

Observe first, then write. Walk the route between your home and your school with a notebook
and write down only what you actually see, with the place and the date. For each problem give
who is affected, who can fix it, and what you yourself can do — that is what turns a complaint into
a solution.

# PROBLEM WHO IT AFFECTS POSSIBLE SOLUTION
OBSERVED

1 Potholes on the road Two-wheeler riders, Report the exact spot to the municipal or
near the bus stop; they autos, the school bus; Panchayat office with a photograph; ask for
fill with water in the accidents happen at the stretch to be repaired before the
rain night monsoon and for a temporary warning
marker meanwhile

2 Garbage lying beside Everyone nearby — More and larger bins with lids, a fixed daily
the bins instead of flies, smell, stray collection time, separate green and blue
inside them animals, blocked drains bins, and a class campaign on segregation

3 Three streetlights not Women, elderly people Report the pole numbers to the electricity
working on the lane and children walking office; ask for solar street lights, which keep
behind the market after dark working during power cuts

4 A public tap that leaks The whole locality, Inform the water supply office the same day;
all day especially in summer fit a self-closing tap; put up a small board
when supply is short asking users to close the tap

5 Names and drawings Everyone — it makes A cleaning drive by the class, a painted wall
scratched on the wall of the place look mural in place of the graffiti, and our
the bus stand and on neglected, and Community Responsibility Pact displayed at
desks repainting costs public the bus stand
money

For the class discussion: rank the five by how many people each problem affects and how
quickly it can be solved. Take up the one that is high on both, write a short application together,
and give it to the Panchayat or municipal office through your teacher.

Tip: Keep a “before” photograph. If the problem is solved, the “after” photograph is
the best possible report on your work — and the best way to persuade the next class
to try it.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Before we move on … — Page 190
The chapter in two points

BEFORE WE MOVE ON …

Q1 Quality infrastructure is the backbone for all other economic activities taking place
in a country. This enables better connectivity, employment opportunities for people
and enhances ease of living.

Explain the point in three parts, exactly as the sentence gives them.

THE CLAIM THE CHAPTER’S EVIDENCE

Backbone for all Transport systems “connect places of origin or manufacturing of goods and services to
other economic the nearest markets”. Satish’s tomatoes need canals, pumps, roads, cold storage and the
activities internet before they can be sold at all

Better connectivity The second-largest road network in the world; NH44 running 4,112 km from Srinagar to
Kanyakumari; the Golden Quadrilateral joining Delhi, Mumbai, Chennai and Kolkata;
metros in 23 cities; 159 airports; 12 major and 217 minor ports along an 11,100 km
coastline

Employment Indian Railways alone employed about 1.21 million people in 2024 — engineers, ticket
opportunities collectors, service staff — besides indirect jobs in catering, vending and taxi services

Ease of living Ambulances reach hospitals; the Dhola Sadiya Bridge cut travel time by four hours and
works even in floods; online classes and digital libraries reach remote areas; e-
governance lets a citizen apply for documents without travelling

Why it happens: the word backbone is well chosen. A backbone does not walk, lift or
think — but nothing else in the body can work without it. In the same way
infrastructure produces no crop and sells no cloth, yet farming, industry, trade,
schooling and government all rest on it. That is why the chapter calls it the engine of
development.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q2 Over time, India has witnessed phenomenal growth in physical infrastructure, and
it is the duty of every citizen to preserve and maintain it.

The sentence has two halves — the growth, and the duty. Both need evidence from the
chapter.
1. The growth, in the chapter’s own numbers

SECTOR WHERE INDIA STANDS

Roads Second-largest road network in the world (2024); national highways about 150,000 km (2025)

Railways Fourth-largest railway system in the world; 69,181 km of track in 2024 (Fig. 7.11); 97 per cent
of the network electrified, the highest among the five countries in Fig. 7.8; over 20 million
passengers a day

Metros 23 cities, over 1,000 km, and soon to be the third-largest network in the world after China and
the USA

Air 159 airports in 2025; third-highest domestic air traffic in the world; about 376 million
passengers in 2024–25

Ports Cargo handled up 50 per cent in the past decade

Communication 1,160 million wireless subscribers and nearly 900 million internet connections in 2025, at
among the world’s cheapest rates

2. The duty — the chapter is equally clear that building is only half the job. Littered roads,
stained buildings, writing on monuments, potholes and broken streetlights “reduce ease of
living for people” and become “a burden for every citizen”. So a citizen must use infrastructure
responsibly and report damage to the authorities. The idea is old: Kautilya’s Arthaśhāstra
already fixed penalties for breaking the dam of a reservoir, for trespassing into public parks by
breaking the hedge, and for obstructing paths to waterworks and forests.

Why it happens: public infrastructure has no single owner, so it is easy for each
person to assume that someone else will look after it. But its repair is paid for out of
money collected from everyone — so careless damage by one person is quietly paid
for by all. Preservation is therefore not politeness; it is arithmetic.

Questions and activities — Pages 191–192

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

End-of-chapter exercise
co m
e m.
m l as
.co a
Which form of physical infrastructure has been built in your area in the last decade?
g
emdo you think it has benefitted you or your family members? If you could build
Q1

a s
How

agl something for the community, what would it be?

. com ag

m
This asks about your own area, so nameesomething
s
a
real and recent. Ask an elder at home
what the place looked like ten years g l — that is the fastest way to spot what is new.
a ago
Method. Answer in three steps: (i) name the new infrastructure and roughly when it came; (ii)

c o m
give two or three specific changes it made to your family’s daily life — time saved, money
.
s em
saved, something now possible that was not; (iii) propose one thing you would build, and say
m a
. co gl
who would use it and why that need is the biggest one.

em a
a s
agl Sample answer: “In my area the biggest change of the last decade is the new
concrete road with a covered drain in our colony, built about four years ago, along
m a s
c o agl
with street lights on solar poles.
.
m became slushy for the whole monsoon and
s e
How it has helped us: earlier the lane
my mother could not take herla
a g scooter out; now she reaches the market in ten
minutes instead of half an hour by autorickshaw. The covered drain stopped the
water logging in front of our gate, so mosquitoes have reduced. The solar lights stay
co m
m .
se
on during power cuts, so my sister feels safe returning from tuition. An autorickshaw

o m g l a
.c
will now come right up to our door, which mattered a great deal when my
m a
aseWhat I would build: a small community library and study room with electricity,
grandfather had to be taken to hospital last year.

agl
m
fans, drinking water and internet. Many children in our colony share one room at

a se
com in the daytime. It needs little land, costs far l
home and cannot study in the evening. A library would serve them, and the same
. a g
em
hall could be used for adult skill classes
less than a road, and wouldabe
l s
g
used every single day.”
a

c o
Why this counts as a good answer: it names one thing, gives dated and specificm
gains rather than “it is very useful”, and its proposal identifies m .
s e a real user and a real

gla
om — which is exactly how infrastructure is actually achosen.
.cneed
se m
g l a
a c
m .
m a s e
e m . co agl
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a

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q2 How does infrastructure like ports, highways, and airports create jobs in different
parts of the country? Can you think of indirect ways people benefit from it?

Jobs come in three waves — building it, running it, and everything that grows up around
it. The chapter shows all three for the railways; the same pattern holds for ports, highways and
airports.

WAVE PORTS HIGHWAYS AIRPORTS

Building it Dredging, jetties, cranes, Surveyors, engineers, machine Terminal construction,
warehouses operators, road workers; runway laying, electrical and
bridge and tunnel builders IT work

Running it Crane and forklift Toll staff, highway patrol, Ground staff, security, air
operators, dock workers, ambulance crews, repair and traffic control, baggage
customs and cargo clerks, marking gangs handlers, cleaning and
ship pilots maintenance

Growing Trucking, cold storage, Dhabas, petrol pumps, tyre Taxis and app-cabs, hotels,
around it packing, ship chandlers, and repair shops, hotels, small courier and cargo firms, shops
godowns workshops and food outlets

Indirect ways people benefit — even those who never use the airport or the port:

Cheaper and fresher goods. Better transport means less spoilage and lower freight, so
vegetables, fruit and medicines cost less in the shop.
Higher prices for producers. A farmer or weaver can now sell to a distant market instead of
only the local one — Satish’s story again.
Better services nearby. Where transport reaches, hospitals, colleges and banks follow,
because staff can commute and supplies can arrive.
New settlements and markets. As the chapter says of railways: “trade grew, major markets
developed, and new settlements emerged near stations”.
Help in a crisis. Cargo flights and highways carry relief to flood- and earthquake-hit areas,
and defence forces reach difficult terrain faster.
Work for those with different skills. The chapter names catering, vending and taxi services
as indirect jobs — work that needs no engineering degree and can be started with very little
money.

Why it happens: a port, a highway or an airport is a place where things must stop
— to be loaded, unloaded, refuelled, checked or transferred. Wherever goods and
people are made to pause, services appear to look after them, and those services
are jobs.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q3 Why is it important to think about the environment when building new
infrastructure like roads or airports? Can infrastructure development and
environmental protection go hand in hand? If yes, how?

It is important because infrastructure lasts for decades, so a careless choice keeps costing
the environment every day for the whole life of the structure. And yes, the two can go
together — the chapter says exactly this when it asks for “safe and sustainable infrastructure
that uses cleaner energy and environment-friendly materials to minimise pollution and harm to
bio-diversity”.
Why the environment must be thought about first

Building takes land — often farmland, forest or wetland — and once it is built over, it cannot
easily be returned.
Construction and traffic bring dust, noise and emissions to places that had none.
A road or a railway line can cut an animal’s path in two. The chapter shows the answer to this
in Fig. 7.28 — alarm systems for when animals cross railway tracks.
Repairing damage later costs far more than designing well once.

How they can go hand in hand — with the chapter’s own examples

CHOICE EXAMPLE FROM THE CHAPTER

Cleaner energy for Solar panels generating electricity for buildings, “to reduce emissions”; the solar power
the structure itself project at Cochin International Airport; the Delhi Metro using solar power

Cleaner energy for 97 per cent of India’s railway network is electrified (Fig. 7.8) instead of running on coal
the vehicles and diesel; electric vehicles are named in the last question as a cheaper, less polluting
alternative

Choosing the less Cargo trains use 75–90 per cent less energy than road transport; metros lower pollution
polluting mode and cut road traffic

Protecting wildlife Alarm systems where animals cross railway tracks (Fig. 7.28)

Building with Meghalaya’s living root bridges — infrastructure that is grown, not poured, and lasts for
nature centuries; Kempegowda International Airport, designed on the ‘garden city’ idea with
bamboo structures, plants and green spaces

Cargo by road: energy used = 100 units (say)

Cargo by train: 75–90 per cent less → 10 to 25 units for the same work

So rail can do the same job for about one-tenth to one-quarter of the energy

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Why it happens: pollution is mostly a sign of energy being wasted. A design that
wastes less energy — an electrified line, a metro carrying a thousand people in one
train, a roof that makes its own power — is cheaper to run and cleaner. That is why
development and protection need not pull in opposite directions.

Q4 How can better infrastructure (like roads, airports, communication systems) help
during natural disasters like floods or earthquakes?

It helps at three moments: before the disaster, during it, and after it. The chapter names
uses at each stage.

STAGE WHAT INFRASTRUCTURE DOES

Before — Communication networks carry “quick mobile SMS alerts or apps”, so people can move to
warning safety in time. Radio and television reach households without phones

During — Roads and bridges let ambulances, fire engines and rescue teams reach the spot. Phone
rescue networks let a trapped family say where they are. Air transport can “reach difficult terrains
like high mountains, deserts, dense forests, and long oceanic stretches”, which is exactly where
roads fail

After — relief Cargo flights move “high-value or perishable goods like vaccines, chemicals, seafood” and aid;
and rebuilding highways and railways bring food, tents, medicines and machinery in bulk; electricity and
water lines restore normal life

The chapter’s clearest single example is the Dhola Sadiya Bridge. Before it was built, people
crossing the Lohit River depended on ferries “which did not work during floods”. Now the bridge
gives year-round travel, cuts four hours from the journey, and lets people “access hospitals or
medicines faster, even during floods”.

Why it happens: a disaster is, above all, a shortage of time — a warning that comes
an hour late, or help that arrives a day late, may be no help at all. Every piece of
infrastructure shortens that time: a message travels in seconds, a bridge saves four
hours, a flight crosses a flooded district in minutes. Infrastructure also gives
alternatives, so that when one route is cut, another still works.

Tip: Notice that infrastructure must itself survive the disaster. That is why the
chapter asks for infrastructure that is safe and sustainable, and why a bridge is
better than a ferry in a flood-prone valley.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q5 Have you ever noticed people misusing public spaces, like scribbling on walls,
breaking streetlights, or damaging benches? What are its consequences? Write
your observations and suggest solutions to prevent it.

Yes — and the chapter’s own list is a good place to check your observations against: “roads
being littered, stains on buildings, or writings on monuments”. Answer in three parts: what
you saw, what it cost everyone, and what would prevent it.
Consequences

MISUSE WHAT FOLLOWS

Scribbling on walls and Repainting and cleaning cost public money; a heritage monument can be permanently
monuments marked, so something that survived centuries is spoilt in a minute

Breaking streetlights A dark road at night — accidents, and people, especially women, elderly people and
children, avoid going out

Damaging benches, bus The people who most need to sit or wait — the elderly, the sick, pregnant women —
shelters, taps lose the facility; a broken tap wastes water for weeks

Littering Blocked drains, water logging in the rains, flies and mosquitoes, extra work for
sanitation staff

Behind all of these is the chapter’s central point: “Such damage to public infrastructure reduces
ease of living for people and becomes a burden for every citizen.” Money spent on repairing
what was needlessly broken is money that could have built something new.
Solutions

1. Make the right thing easy. Enough dustbins, working taps, benches and lights — people
misuse a place that already looks neglected far more readily than one that is well kept.
2. Make it belong to someone. Let a class, a resident’s group or a shopkeepers’ association
“adopt” a park, a bus stop or a stretch of wall, with their name on a small board.
3. Replace blank walls with murals. A painted wall is scribbled on far less than a plain one.
4. Report quickly. Put the Panchayat or municipal helpline number on the bus stop itself, so
anyone can report a broken light or an open manhole.
5. Repair fast. One unrepaired broken bench invites the next one to be broken.
6. Rules with consequences. The chapter notes that the government can impose penalties to
deter damage — and that the Arthaśhāstra did the same thousands of years ago, fining
those who broke the dam of a reservoir or the hedge of a public park.

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co m
m.
Sample observation: “At our bus stop, two of the four plastic seats are broken and

m l a se
the timetable board is covered with film posters. Elderly passengers stand in the sun
o
.cminutes. Our class wrote to the municipal office, pasted
a g a small ‘Please do
m
for twenty
se posters’ board, and painted a mural of the town’s river on the back wall.
notastick
l
g months later the mural was still untouched, and no new posters had been stuck
aFour
on it.”
co m
e m . ag
g l as
Q6
a
Prepare ‘scenario posters’ for the following situations: • A new factory is planned in
an area. What form of infrastructure is required for its smooth operation? • Self-
com
m.
cleaning roads, underground highways, and high-speed bullet trains could be part

o m l a se
of a futuristic city! Imagine the kind of infrastructure that would be required in the
g
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future in your city,

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mountainous, plains, etc., and the type of natural calamities your region is prone
om a
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to. • If you could design a new railway or metro station, what would it look like and
what features would you add e
s mmake it more fun and comfortable for the
a
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passengers?

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Four posters, one per scenario. Keep each poster to a large drawing plus
s e mshort labels — a
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poster isom a gla five or six labelled
read standing up, so no long paragraphs. Use a title, a sketch,

a s em and one line at the bottom saying who benefits.
features,

agl Poster 1 (first situation) — “What a new factory needs”
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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

NEED INFRASTRUCTURE

Raw material in, An approach road strong enough for loaded trucks, joined to a state or national
finished goods out highway; a railway siding or a nearby goods station; a port or airport for exports

Power A reliable electricity connection and substation; a rooftop solar plant to cut costs and
emissions

Water Water supply pipeline, storage tank, and a treatment plant so used water is cleaned
before release

Workers Bus service or shared transport, housing nearby, a health centre, a school for workers’
children, drinking water and toilets on site

Information and money Internet and telephone connection for orders, prices and payments; banking access

Storage Warehouse; cold storage if the goods are perishable

Safety and Fire station within reach, waste disposal system, a green belt around the plot
environment

Poster 2 (second situation) — “Our city in 2050”
Draw the town in cross-section, and label: self-cleaning and solar-paved roads; an underground
expressway keeping through-traffic out of the market; a high-speed train to the state capital; a
metro or e-bus network with charging points at every stop; rooftop solar on every school and
hospital; rainwater harvesting and a recharge pit in every ward; drones carrying medicines to
the villages beyond the river; underground bins with sensors that call the collection truck when
full; free public Wi-Fi at bus stands and libraries; sensors on bridges and drains that warn the
municipality before a failure. Bottom line: “Faster, cleaner, and reaching everyone — town and
village alike.”
Poster 3 (third situation) — “The right upgrade for our land”
The point of this poster is that terrain decides the answer, so first write your own terrain across
the top.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

TERRAIN COMMON UPGRADES TO SHOW ON THE POSTER
CALAMITY

Coastal Cyclone, storm Cyclone shelters on raised ground, mangrove belts, all-weather
surge, salt damage evacuation roads, siren towers, buried power cables, fishing
harbours with safe moorings

Mountainous Landslide, snow Tunnels and slope-protection walls, earthquake-resistant
blockage, buildings, ropeways, helipads, satellite phones at the health
earthquake centre, all-weather roads

River plains Flood, water logging Embankments and proper drainage, bridges instead of ferries
(like the Dhola Sadiya Bridge), raised roads and schools, flood-
warning SMS alerts, raised handpumps that stay clean

Dry / desert Drought, heat wave Rainwater harvesting and traditional tanks, piped water, shaded
bus stops, solar power, heat-reflective roofs

Poster 4 (fourth situation) — “Our dream station”
Draw the station front and platform, and label these features:

Comfort: shaded and cooled waiting hall, clean toilets, free drinking-water points, feeding
room for mothers, plenty of seating with armrests, phone-charging points.
Access for all: ramps, lifts, tactile paths and Braille signs for the visually impaired,
wheelchairs at the entrance, wide gates, signs in the local language, Hindi and English — the
chapter asks that design consider “the needs of children, the elderly and disabled persons”.
Fun: a children’s play corner, a mural of the district’s history and crafts, a small book and
reading corner, live local music on weekends, a food court selling the region’s dishes.
Green: solar roof, rainwater harvesting, indoor plants, segregated bins, and a garden
forecourt — like the ‘garden city’ idea used at Kempegowda International Airport, with its
bamboo structures and green spaces.
Smart: real-time train display, an app for the coach position, digital ticketing, CCTV and a
clearly marked help desk.
Connections: a covered walkway to the bus stand, an autorickshaw and app-cab bay, and a
cycle stand — so the journey continues smoothly.

Why these posters work: each one answers the same question in a different setting
— what must exist before this place can work well? That is the habit the chapter is
trying to build: seeing infrastructure as a system of connected pieces rather than as
separate buildings.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Q7 Today's modern infrastructure requires consistent technological innovations. For
instance, electric vehicles are increasingly being used by people as a cheaper
alternative to polluting fuel like diesel or petrol. Find out about other innovations
in infrastructure that can improve ease of living or mobility for communities.

This is a find-out task, so use sources you can name — the chapter itself, a newspaper, a
school library book, or an elder who works in transport, electricity or construction. For each
innovation write three things: what it is, what problem it solves, and who benefits.
Innovations already named in this chapter — start here, because they are safest to quote:

INNOVATION PROBLEM IT SOLVES

Electrified railway lines Removes coal and diesel from trains; India’s network was 97 per cent electrified
in 2024, the highest among the five countries in Fig. 7.8

Solar power on infrastructure The solar project at Cochin International Airport; the Delhi Metro’s use of solar
power; solar panels on buildings to cut emissions

Metro rail on elevated and Cuts travel time and road traffic in 23 cities without taking more road space
underground tracks

Long bridges and tunnels Dhola Sadiya Bridge across the Lohit; the Chenab Rail Bridge, the world’s
highest railway bridge; Atal Setu, India’s longest sea bridge — these reach places
roads could not

Animal-crossing alarm Warns of animals on railway tracks, protecting both wildlife and passengers
systems (Fig. 7.28)

Elderly-friendly transport Ramps, handrails and level boarding for smooth mobility (Fig. 7.29)
design

E-governance and e- DigiLocker for documents; online payments; a small seller reaching distant
commerce buyers

Other innovations worth finding out about (check each in a newspaper or library book before
you write it in your notebook):

EV charging stations along highways and in housing colonies — an electric vehicle is only as
useful as the places it can be charged.
Solar street lighting and solar pumps, which keep working during a power cut and cost
nothing to run.
LED street lights and smart meters, which cut electricity use for the same light.
Cold chains — refrigerated trucks and cold storages that let a farmer’s produce, or a
vaccine, travel without spoiling.
Rainwater harvesting and drip irrigation, which stretch a limited water supply further.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Prefabricated construction, where parts are made in a factory and assembled on site, so a
bridge or a school block is finished faster and with less waste.
Real-time public transport apps and digital ticketing, which remove the guesswork and the
queue.
Waste-to-compost and waste-to-energy plants, which turn a disposal problem into a
resource.

How to present it: make a two-page spread in your notebook — a title, a drawing or
a cut-out picture, and your three lines for each innovation. Underneath, write one
sentence on the innovation you would most want in your own locality, and why.
Name your sources at the end.

Why innovation matters here: infrastructure is expensive and long-lived, so
improvements usually come not from building everything again but from making
what exists work better — the same track carrying electric trains, the same roof also
making power, the same phone also delivering government services. That is what
the chapter means by “consistent technological innovations”.

Chapter at a glance
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 the
trucks, cold storage to stay fresh, and the internet for input and price information. Remove
one link and the whole chain suffers.
Transport: five networks. India has the world’s second-largest road network after the
USA (2024); national highways are about 150,000 km, with NH44 the longest at 4,112 km
(Srinagar to Kanyakumari). Railways began in 1853 under British rule, and today carry over
20 million passengers a day and employ about 1.21 million people (2024). Metros run in 23
cities over more than 1,000 km. India had 159 airports in 2025 and about 376 million air
passengers in 2024–25. Its 11,100 km coastline serves 12 major and 217 minor ports.

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as e
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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Communication changed from couriers to cloud. Fig. 7.23 runs from pigeons, runners
co m
se
and horse couriers (200 BCE–1200 CE) through the Bengal Gazette (1780), the telegraph
m.
o m l a
g and 5G, cloud
.c computers (1970), the internet and World Wide Weba(1994),
(1844), the telephone (1876) and J.C. Bose’s wireless demonstration (1899), to All India Radio

se m
(1930), personal

l a
agtelephone subscribers and nearly 900 million internet connections.
communication and AI-driven services today. In 2025 India had 1,160 million wireless

m
Good infrastructure changes ordinary lives. The Dhola Sadiya Bridge (9.15 km, India’s

. co ag
m
second longest) replaced ferries that stopped during floods, and cut travel time by four

l a se
hours — so vegetables now reach the market before they spoil and hospitals can be
g root bridges (jingkieng jri), grown by Khāsi and Jaintia
reached in a flood. Meghalaya’saliving
communities from the roots of the Indian rubber tree, stand 15–30 m high and last for
centuries — infrastructure that is also knowledge and culture.
c o m
.
m roads, stained
Looking after infrastructure is a shared duty — and an old idea. Littered
s e
. c
buildings,omwriting on monuments and potholes reduce ease of living
a g lafor everyone. Kautilya’s
s e m
Arthaśhāstra already laid down road widths (about 16 m for royal highways, 8 m for city

a glaand forest roads, 2.5 m for chariot roads) and penalties for damaging waterworks or
blocking public paths. The chapter also asks for infrastructure that is sustainable and

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designed for children, the elderly and disabled persons.

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

Quick revision

TERM OR FACT WHAT IT MEANS WHERE IT WORTH REMEMBERING
APPEARS IN
THE
CHAPTER

Physical The vast network of tangible Page 170, Four families: transport, utilities,
infrastructure structures built to keep cities Introduction communication, energy
and villages functioning

Social Schools, colleges, training THINK ABOUT Physical infrastructure carries things;
infrastructure centres, hospitals, health IT, page 188 social infrastructure builds people
centres, police and fire stations,
courts, parks, libraries,
community centres

National Fast roads joining cities across Pages 173–175 About 150,000 km (2025); NH44 is
highways states, built and maintained by longest at 4,112 km
the central government

State highways Roads connecting towns and Page 173 Below them are the local roads that
districts within a state, built and reach homes, fields and schools
maintained by state public
works departments

Golden Highway network connecting DON’T MISS Four cities, four corners of the
Quadrilateral Delhi, Mumbai, Chennai and OUT, page 175 country
Kolkata

Dhola Sadiya Bridge over the Lohit River Page 175, Fig. 9.15 km, India’s second longest; cut
Bridge (Bhupen joining Assam and Arunachal 7.5 travel time by 4 hours
Hazarika Setu) Pradesh

Living root A bridge grown from the roots Pages 175–176, Made by the Khāsi and Jaintia tribes;
bridge (jingkieng of the Ficus elastica (Indian Fig. 7.6 15–30 m high; takes decades to
jri) rubber tree), guided across mature
streams with bamboo and palm
trunks

Indian Railways Started by the British in 1853 to Pages 176–179 Over 20 million passengers a day;
move raw materials to ports; about 1.21 million employees (2024)
today the world’s fourth-largest
railway system

Electrified Share of railway track that runs Fig. 7.8, page India 97% · China 75% · France 61% ·
railway network on electricity instead of coal or 177 Germany 55% · UK 38% (2024)
diesel

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

TERM OR FACT WHAT IT MEANS WHERE IT WORTH REMEMBERING
APPEARS IN
THE
CHAPTER

Length of railway Country-wise comparison of Fig. 7.11, page USA 293,564 · China 150,000 · Russia
track, 2024 total track length 179 85,494 · India 69,181 · Canada 48,000
km

Metro train Fast urban rail on underground Page 180 23 cities, over 1,000 km; Delhi Metro
systems and elevated tracks uses some solar power

Air transport Fastest link between people and Pages 180–182 159 airports in 2025; about 376
places; passenger flights and million passengers in 2024–25
cargo flights

Ports and Ships dock at ports where heavy Pages 183–184, Coastline about 11,100 km; 12 major
shipping goods are loaded and unloaded Figs. 7.21–7.22 and 217 minor ports; cargo up 50%
in a decade

TEU Twenty-foot Equivalent Units Note under Fig. Generally 1 TEU = 33 cubic metres;
— a measure of container-ship 7.21, page 183 these numbers need not be
capacity and port activity memorised

E-commerce Buying or selling products and Margin note, Lets a small seller reach buyers
services on online platforms or page 185 across the world
over the internet

E-governance Use of communication Margin note, Example: the DigiLocker app for
technologies by government to page 185 Aadhaar card and driving licence
deliver services to citizens

Patent A right granted by the Margin note, J.C. Bose rarely patented his
government or an institution to page 186 inventions
be the only person or company
who can make, sell or use an
invention for a certain number
of years

J.C. Bose (1858– Indian scientist who pioneered DON’T MISS Calcutta experiment 1895; invented a
1937) wireless transmission using OUT, pages new coherer; founded the Bose
microwaves in the millimetre 186–187 Institute in 1917
range

Arthaśhāstra Kautilya’s text setting road Page 189 Royal/countryside/port/village roads
road rules widths by the traffic they 16 m · forest and city roads 8 m ·
carried, and penalties for chariot roads 2.5 m
damaging public works

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Class 7 Social Science Chapter 19 Infrastructure: Engine of India’s Development AglaSem · NCERT Solutions

TERM OR FACT WHAT IT MEANS WHERE IT WORTH REMEMBERING
APPEARS IN
THE
CHAPTER

Collective Public infrastructure belongs to Pages 188–190 Report potholes and broken
responsibility everyone, so using it well and streetlights; do not deface walls or
reporting damage is every monuments
citizen’s duty

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