NCERT Solutions for Class 7th Social Science Chapter 19 End-of-chapter exercise — Questions and activities

Book page 191–192 Updated on2026-09-19

Q1.

Which form of physical infrastructure has been built in your area in the last decade? How do you think it has benefitted you or your family members? If you could build something for the community, what would it be?

Answer

This asks about your own area, so name something real and recent. Ask an elder at home what the place looked like ten years ago — that is the fastest way to spot what is new.

Method. Answer in three steps: (i) name the new infrastructure and roughly when it came; (ii) give two or three specific changes it made to your family’s daily life — time saved, money saved, something now possible that was not; (iii) propose one thing you would build, and say who would use it and why that need is the biggest one.

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 with street lights on solar poles.
How it has helped us: earlier the lane became slushy for the whole monsoon and my mother could not take her 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 on during power cuts, so my sister feels safe returning from tuition. An autorickshaw will now come right up to our door, which mattered a great deal when my grandfather had to be taken to hospital last year.
What I would build: a small community library and study room with electricity, fans, drinking water and internet. Many children in our colony share one room at home and cannot study in the evening. A library would serve them, and the same hall could be used for adult skill classes in the daytime. It needs little land, costs far less than a road, and would be used every single day.”

Why this counts as a good answer: it names one thing, gives dated and specific gains rather than “it is very useful”, and its proposal identifies a real user and a real need — which is exactly how infrastructure is actually chosen.

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?

Answer

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, warehouses	Surveyors, engineers, machine operators, road workers; bridge and tunnel builders	Terminal construction, runway laying, electrical and IT work
Running it	Crane and forklift operators, dock workers, customs and cargo clerks, ship pilots	Toll staff, highway patrol, ambulance crews, repair and marking gangs	Ground staff, security, air traffic control, baggage handlers, cleaning and maintenance
Growing around it	Trucking, cold storage, packing, ship chandlers, godowns	Dhabas, petrol pumps, tyre and repair shops, hotels, small workshops	Taxis and app-cabs, hotels, courier and cargo firms, shops 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.

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?

Answer

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 the structure itself	Solar panels generating electricity for buildings, “to reduce emissions”; the solar power project at Cochin International Airport; the Delhi Metro using solar power
Cleaner energy for the vehicles	97 per cent of India’s railway network is electrified (Fig. 7.8) instead of running on coal and diesel; electric vehicles are named in the last question as a cheaper, less polluting alternative
Choosing the less polluting mode	Cargo trains use 75–90 per cent less energy than road transport; metros lower pollution and cut road traffic
Protecting wildlife	Alarm systems where animals cross railway tracks (Fig. 7.28)
Building with nature	Meghalaya’s living root bridges — infrastructure that is grown, not poured, and lasts for 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

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?

Answer

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 — warning	Communication networks carry “quick mobile SMS alerts or apps”, so people can move to safety in time. Radio and television reach households without phones
During — rescue	Roads and bridges let ambulances, fire engines and rescue teams reach the spot. Phone 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 and rebuilding	Cargo flights move “high-value or perishable goods like vaccines, chemicals, seafood” and aid; 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.

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.

Answer

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 monuments	Repainting and cleaning cost public money; a heritage monument can be permanently 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 shelters, taps	The people who most need to sit or wait — the elderly, the sick, pregnant women — 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

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.
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.
Replace blank walls with murals. A painted wall is scribbled on far less than a plain one.
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.
Repair fast. One unrepaired broken bench invites the next one to be broken.
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.

Sample observation: “At our bus stop, two of the four plastic seats are broken and the timetable board is covered with film posters. Elderly passengers stand in the sun for twenty minutes. Our class wrote to the municipal office, pasted a small ‘Please do not stick posters’ board, and painted a mural of the town’s river on the back wall. Four months later the mural was still untouched, and no new posters had been stuck on it.”

Q6.

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-cleaning roads, underground highways, and high-speed bullet trains could be part of a futuristic city! Imagine the kind of infrastructure that would be required in the future that could help ease the lives of the people and communities in your city, town or village for various day-to-day functions. • Think about upgrades to the infrastructure near you, considering the terrain of your area, such as coastal, mountainous, plains, etc., and the type of natural calamities your region is prone to. • If you could design a new railway or metro station, what would it look like and what features would you add to make it more fun and comfortable for the passengers?

Answer

Four posters, one per scenario. Keep each poster to a large drawing plus short labels — a poster is read standing up, so no long paragraphs. Use a title, a sketch, five or six labelled features, and one line at the bottom saying who benefits.

Poster 1 (first situation) — “What a new factory needs”

Need	Infrastructure
Raw material in, finished goods out	An approach road strong enough for loaded trucks, joined to a state or national 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 environment	Fire station within reach, waste disposal system, a green belt around the plot

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.

Terrain	Common calamity	Upgrades to show on the poster
Coastal	Cyclone, storm surge, salt damage	Cyclone shelters on raised ground, mangrove belts, all-weather evacuation roads, siren towers, buried power cables, fishing harbours with safe moorings
Mountainous	Landslide, snow blockage, earthquake	Tunnels and slope-protection walls, earthquake-resistant buildings, ropeways, helipads, satellite phones at the health 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.

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.

Answer

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 underground tracks	Cuts travel time and road traffic in 23 cities without taking more road space
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 systems	Warns of animals on railway tracks, protecting both wildlife and passengers (Fig. 7.28)
Elderly-friendly transport design	Ramps, handrails and level boarding for smooth mobility (Fig. 7.29)
E-governance and e-commerce	DigiLocker for documents; online payments; a small seller reaching distant 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.
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”.

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