NCERT Solutions Curiosity Chapter 11 Projects and further exploration — Learning further

Book page 229 & 230 Updated on2026-09-05

Q1.

Rainwater harvesting is an age-old practice in India. Find out some of the traditional rainwater harvesting techniques being used in your state or in other parts of the country.

Answer

Every region of India invented a method that suited its own rainfall, soil and slope. Find the one from your state in this table and then ask an elder about it.

Technique	State / region	How it works
Bawadi / Baoli (stepwell)	Rajasthan	Deep stepped well; stores rainwater and water seeping from nearby lakes, ponds and rivers — Toorji ka Jhalra, Jodhpur (Fig. 11.4b); Chand Baori, Abhaneri
Vav	Gujarat	Stepwell — Rani ki Vav, Patan (a World Heritage Site) and Adalaj ni Vav
Tanka and Kund	Western Rajasthan	Underground tank in a courtyard, fed by a sloping catchment; keeps drinking water cool
Johad and Khadin	Rajasthan (Alwar, Jaisalmer)	Earthen check dam across a slope; embankment that holds runoff on farmland until the crop is sown
Virda	Kutch, Gujarat	Shallow wells dug in low ground where sweet rainwater floats above the salty water
Ahar–Pyne	Bihar (Magadh region)	Diversion channels (pyne) feed a reservoir with three embankments (ahar)
Eri (tanks)	Tamil Nadu	Chains of village tanks; the overflow of one fills the next, so no rain is lost
Kere, Kalyani, Pushkarni	Karnataka	Village tanks and stepped temple tanks
Phad and Bandhara	Maharashtra (Nashik, Dhule)	A stone weir on a stream diverts water into canals serving blocks of fields
Haveli system	Madhya Pradesh (Bundelkhand)	Rain is held on the field itself by low bunds through the monsoon
Katas, Mundas, Bandhas	Odisha, Jharkhand	Earthen tanks on the upper part of a slope for the fields below
Kuhl / Kul, Naula, Guhl	Himachal Pradesh, Jammu, Uttarakhand	Small stone-lined canals from a glacier stream; a naula is a stepped tank built over a spring
Zing	Ladakh	Tank that collects glacier melt-water during the day for use in the evening
Bamboo drip irrigation	Meghalaya	Split bamboo pipes carry spring water down the hill, drop by drop, to betel and pepper plants
Zabo (Ruza)	Nagaland	Rain caught on a hilltop, passed through cattle yards and on to terraced fields and fish ponds
Surangam	Kerala, Kasaragod	A tunnel cut into a laterite hillside that taps water seeping through the rock
Cheruvu, Kunta	Telangana, Andhra Pradesh	Village tanks and small ponds, revived under the Mission Kakatiya programme

How to present the project: pick one method, draw a labelled sketch of it, write where it is used, how it is built, who maintains it, and whether it still works today. Add a photograph or a rubbing from a plaque if there is such a structure near you.

Modern version: rooftop rainwater harvesting (Fig. 11.4a) is the same idea with pipes — rain from the roof goes into a filter, then into a storage tank or a recharge pit. Many Indian cities now make it compulsory for new buildings.

Q2.

Investigate the effect of air pollution on human health by interacting with your elders or community members and identify the main sources of air pollution in your local area. Based on your findings, suggest two practical steps that your school or community could take to help reduce air pollution.

Answer

Part A — How to carry out the investigation

Make a short questionnaire (6–8 questions) — for example: Has the air here changed in the last twenty years? Do you or anyone at home get cough, breathlessness, watering eyes or asthma? Is it worse in any particular season? What do you think causes it?
Interview 10 to 15 people — grandparents, neighbours, a shopkeeper on the main road, a traffic policeman, the school gardener and, if possible, a doctor or ASHA worker.
Observe for yourself — wipe a white cloth on a window sill facing the road and another on an inner window, and compare the dust. Note when smoke is worst (morning traffic, garbage burning in the evening, stubble burning after harvest).
Record everything in a table and count how many people reported each problem.

Part B — What such an investigation usually finds

Effect on health reported	Main local sources identified
Cough, sore throat and repeated colds	Smoke from vehicles on the main road
Breathlessness and asthma, worse in winter	Burning of garbage, dry leaves and plastic
Watering, burning eyes	Dust from construction sites and unpaved roads
Headache and tiredness	Diesel generators, brick kilns or a nearby factory chimney
Smoky kitchens, eye irritation in elderly women	Cooking on firewood, coal or dung cakes
Cough after the harvest season	Burning of crop stubble in the fields

Part C — Two practical steps (choose the two that fit your findings)

A “No-vehicle day” and a walking bus for the school. One day a week, everyone within two kilometres walks or cycles; others share rides. Ask parents not to keep engines running in the pick-up line — a “switch off your engine” board at the gate.
A “no burning, only composting” rule for the school and colony. Put up two bins, compost the dry leaves and kitchen waste in a pit instead of burning them, and hand the compost to the school garden. Add a plantation drive along the boundary wall, since trees trap dust and take in carbon dioxide.

Why the interviews matter: numbers from a book are distant; hearing a neighbour say “I could see the hills from here as a child” makes the change real, and it teaches you that evidence can also be collected by asking, not only by measuring.

Q3.

Prepare a list of the names and uses of important minerals and rocks that are used in your village/town/city for various purposes.

Answer

How to do it: walk around your locality with a notebook. Look at the floor of your school, the walls of a temple, the kerb stones, the road metal, a construction site and a hardware shop. Ask the mason or the shopkeeper what each material is and where it comes from.

Rocks — what to look for

Rock	Where you will see it	Where it comes from in India
Granite	Kitchen platforms, floor slabs, temple pillars, monuments	Karnataka, Telangana, Tamil Nadu, Rajasthan
Marble	Floors, statues, temple work, table tops	Makrana and Kishangarh (Rajasthan)
Sandstone	Building walls, carved brackets, paving	Dholpur and Jodhpur (Rajasthan)
Slate	Roofing (Fig. 11.6), flooring, writing slates	Kangra (Himachal Pradesh), Markapur (Andhra Pradesh)
Laterite	Cut into blocks and used like bricks (Fig. 11.7)	Kerala, coastal Karnataka, Goa, Konkan, Odisha
Limestone	Raw material of cement; chuna for whitewash	Rajasthan, Madhya Pradesh, Andhra Pradesh, Gujarat
Basalt / trap rock	Road metal, railway ballast, building stone	Deccan plateau — Maharashtra, Madhya Pradesh
Gravel and sand	Concrete, plaster, mortar	River beds and quarries near every town

Minerals — what they become

Mineral / metal	Used for	Mined mainly in
Iron ore → iron and steel	Grills, gates, rods for building, tools, vehicles, railway lines	Odisha, Chhattisgarh (Bailadila), Jharkhand, Karnataka, Goa
Bauxite → aluminium	Vessels, window frames, foil, aeroplane bodies, electric wires	Odisha (Panchpatmali), Jharkhand, Gujarat, Chhattisgarh
Copper ore → copper	Electrical wiring, utensils, temple bells	Khetri (Rajasthan), Singhbhum (Jharkhand), Malanjkhand (Madhya Pradesh)
Gold and silver	Jewellery, and tiny contacts inside mobile phones	Kolar and Hutti (Karnataka)
Manganese	Making strong steel, dry cells	Odisha, Balaghat (Madhya Pradesh), Nagpur–Bhandara (Maharashtra)
Mica	Electrical insulation, cosmetics, paints	Koderma (Jharkhand), Nellore (Andhra Pradesh), Rajasthan
Gypsum	Plaster of Paris, false ceilings, cement	Rajasthan, Tamil Nadu
Salt (halite)	Cooking and preserving food	Sambhar Lake (Rajasthan); coastal salt pans of Gujarat and Tamil Nadu

What the list will teach you: nearly every hard thing around you began as a rock or a mineral dug out of the ground somewhere in India — and every one of them is non-renewable. That is why the chapter asks us to conserve rocks and minerals and use them responsibly.

Add one column of your own: “Can it be reused or recycled?” Iron, aluminium and copper can be melted and used again — recycling them saves both the mineral and the fuel needed to mine it.

Q4.

You are an eco-club monitor. Organise a tree plantation drive in your school with the help of your teacher. List the steps required for organising this activity. Prepare a one-page report listing the names of the trees planted along with their importance.

Answer

Part A — Steps for organising the drive

Take permission and fix a date. Meet the Principal with a written proposal. Choose the beginning of the monsoon — Van Mahotsav week in July is the best time, as new plants get natural rain.
Survey the space. Walk around the school and mark on a rough map where trees can go — along the boundary wall, behind the playground, near the gate. Avoid places above water pipes or under electric wires.
Choose the right trees. Prefer native species suited to your area, and mix fruit, flower and shade trees.
Arrange saplings and materials. Ask the Forest Department nursery, the municipality or a local nursery — they often give saplings free. Collect spades, watering cans, manure, and tree guards made of bamboo or old wire mesh.
Form teams. Two students per sapling, with one class teacher in charge of each group. Assign jobs: digging, planting, watering, labelling, photography, reporting.
Dig the pits a day earlier — about 45 cm across and 45 cm deep — and mix in compost or manure.
Plant on the day. Remove the polythene bag carefully without breaking the root ball, place the sapling upright, fill and press the soil, water at once, and fix the tree guard and a name label.
Plan the aftercare — the most important step. Make a watering roster for the whole year, including the summer holidays. A sapling that nobody waters is a wasted sapling.
Record and celebrate. Photograph each sapling with its team, measure its height every month, and hold a small “tree adoption” certificate ceremony.

Part B — Sample one-page report

Report: Tree Plantation Drive, Van Mahotsav Week

Date: 12 July Place: School boundary and back garden Saplings planted: 30 Participants: 60 students of Classes 6–8, 5 teachers, 2 gardeners

Tree planted	Number	Its importance
Neem	6	Medicinal leaves, twigs used as datun, keeps insects away, dense shade
Peepal	2	Very long-lived, gives out plenty of oxygen, home for birds; sacred in India
Banyan	1	Huge shade, fruits feed birds and bats; our national tree
Amla	4	Fruit rich in vitamin C — the same nellikai Ajji’s family collects
Mango	3	Fruit, shade and timber; our national fruit tree
Jamun	3	Fruit for people and birds; roots take up a lot of water and hold the soil
Gulmohar	3	Fast-growing, bright flowers, good shade over the cycle stand
Moringa (drumstick)	4	Leaves and pods are highly nutritious; grows quickly
Curry leaf and tulsi	4	Kitchen and medicinal use; suitable for pots near the classrooms

Aftercare: Class 6-A waters Monday and Thursday, 6-B Tuesday and Friday; the gardener waters on holidays. Height of each sapling to be measured on the first of every month and entered in the eco-club register.

What we learnt: planting takes one morning; keeping a tree alive takes a year. Increasing the green cover is not an event — it is a habit.

Why native trees: a neem, peepal or jamun is already suited to the local soil and rainfall, needs little care once established, and feeds local birds and insects. An imported ornamental tree may look pretty but supports far less life.

Was this helpful? Report an error