Consider the following statements: Statement-I. According to the United Nations' 'World Water Development Report, 2022', India extracts more than a quarter of the world's groundwater withdrawal each year. Statement-II. India needs to extract more than a quarter of the world's groundwater each year to satisfy the drinking water and sanitation needs of almost 18% of world's population living in its territory. Which one of the following is correct in respect of the above statements?

(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I

(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I

(d) Statement-I is incorrect but Statement-II is correct

Prelims · Geography · 39 questions

India: relief, rivers & drainage

Every UPSC Prelims question on this topic, 2016–2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

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UPSC syllabus: “Indian and World Geography-Physical, Social, Economic Geography of India and the World.” See the full syllabus →

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Prelims 2026 · Q11

Hard Provisional key

Consider the following assertion:

In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed into the Yamuna and one major tributary of either had shifted from the Ganga to the Indus or vice versa.

Which of the following is/are the basis of the above assertion?

1.The Nadi-Sukta of the Rigveda
2.The explorations of the Sutlej and the Yamuna by Robert Bruce Foote
3.The presence of the same species of dolphins in both the Indus and the Ganga river systems

Select the answer using the code given below:

Answer & explanation

Answer: (d) 3

River dolphins live only in fresh water and cannot pass from one river system to another through the sea. Finding the same kind of dolphin in both the Indus and the Ganga systems was therefore read as proof that the two systems were once joined, with a tributary such as the Yamuna or the Sutlej changing sides in the Pleistocene.

✗ 1. The Nadistuti (Nadi) Sukta is a hymn in praise of the rivers of north-west India. It names the rivers in order but says nothing about Pleistocene river courses.
✗ 2. Robert Bruce Foote is known for discovering Palaeolithic tools in South India (Pallavaram, 1863), not for exploring the Sutlej and the Yamuna.
✓ 3. A freshwater dolphin common to the Indus and the Ganga systems implies an old connection between them, which is exactly what the assertion claims. The Convention on Migratory Species document proposed by India treats the South Asian river dolphin, Platanista gangetica, as one species spread across rivers in India, Pakistan, Bangladesh and Nepal (the Indus form being a subspecies).
• Since then The Indus and Ganges dolphins were long treated as one species; since 2021 scientists list them as two species, Platanista minor and Platanista gangetica (Britannica). The old argument used the single-species view.

Remember · The shared South Asian river dolphin of the Indus and Ganga systems is the classic clue that the two drainages were once linked through a shifting tributary.

📘 Read it in NCERT: Class 7 Exploring Society: India and Beyond (Part 1), Ch 8 (practise this chapter)

Sources

NCERT Class 7 · Exploring Society: India and Beyond (Part 1), Chapter 8 “The nadistuti sukta of the Rigveda is a hymn (sukta) in praise of (stuti) rivers (nadi) that invokes 19 major rivers of ancient northwest India.”
Convention on Migratory Species (UNEP/CMS), COP13 Concerted Action 13.6, South Asian River Dolphin (proposed by the Government of India) ↗ “The South Asian River Dolphin, Platanista gangetica spread across rivers in India, Pakistan, Bangladesh and Nepal.”
Encyclopaedia Britannica, Ganges river dolphin ↗ · reference work “the Ganges river dolphin ( Platanista gangetica ) and the Indus river dolphin ( P. minor ), which are classified as endangered species”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2026 · Q13

Medium Provisional key

Which of the following pairs of ancient and modern names of rivers is/are correctly matched?

1.Vitasta: Chenab
2.Asikni: Jhelum
3.Parushni: Ravi
4.Yavyavati: Beas

Select the answer using the code given below:

Answer & explanation

Answer: (c) 3 only

The Rigvedic names of the Punjab rivers are Vitasta (Jhelum), Asikni (Chenab), Parushni (Ravi), Vipasa/Vipash (Beas) and Sutudri/Shutudri (Sutlej). Pairs 1 and 2 are swapped and the Beas was the Vipasa, so only Parushni-Ravi is right.

✗ 1. Vitasta is the Jhelum; the Chenab was called Asikni.
✗ 2. Asikni is the Chenab; the Jhelum was the Vitasta.
✓ 3. Parushni is the Rigvedic name of the Ravi.
✗ 4. The Beas was the Vipasa (Sanskrit Vipasha), not Yavyavati.

Remember · Rigvedic Punjab rivers: Vitasta–Jhelum, Asikni–Chenab, Parushni–Ravi, Vipash–Beas, Shutudri–Sutlej.

Sources

Encyclopaedia Britannica, Beas River ↗ · reference work “Beas also spelled: Bias (Show more) Ancient Greek: Hyphasis (Show more) Sanskrit: Vipasha”
Exploration Techniques in Archaeology, e-PG Pathshala (INFLIBNET Centre, UGC / Ministry of Education), Indian Archaeology course ↗ · reference work “the Rig Veda provides ample evidence of the Sindhu (Indus River) along with its tributaries like Drishadvati, Sarasvati, Sutudri (Satluj), Vipasa (Beas), Parushni (Ravi), Asikni (Chenab), Vitasta (Jhelum), Suvastu (Swat), Kubha (Kabul), Gomati (Gomal)”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2026 · Q25

Medium Provisional key

Identify the river of the Indian sub-continent on the basis of the following information:

1.It has an antecedent drainage system.
2.It flows through three countries.
3.It originates in the Tibetan Plateau and is an important river for irrigation.
4.It does not form distributaries.

Select the answer from the following:

Answer & explanation

Answer: (c) Sutlej

The Sutlej (Satluj) rises near Mansarovar in Tibet, cuts across the Himalaya at Shipki La as an antecedent river, and feeds the Bhakra Nangal canals. It flows through China, India and Pakistan and ends as a tributary, merging into the Panjnad that joins the Indus, so it forms no delta or distributaries of its own.

✓ (c) All four clues fit: antecedent gorge across the Himalaya, three countries (China, India, Pakistan), a Tibetan source with major irrigation use, and a tributary that ends in another river rather than building distributaries.
✗ (b) The Indus is also antecedent and Tibetan, but it ends in a large delta on the Arabian Sea with several distributaries.
✗ (a) The Brahmaputra flows through China, India and Bangladesh but splits into many channels in the Ganga–Brahmaputra delta.

Remember · Satluj: rises at Rakas Tal near Mansarovar (Langchen Khambab), crosses Shipki La, antecedent; feeds Bhakra Nangal; joins the Indus via the Panjnad.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter) · Class 11 India: Physical Environment, Ch 3 (practise this chapter) · Class 11 India: Physical Environment, Ch 3 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “The Satluj originates in the 'Raksas tal' near Mansarovar at an altitude of 4,555 m in Tibet where it is known as Langchen Khambab.”
NCERT Class 11 · India: Physical Environment, Chapter 3 “It is an antecedent river. It is a very important tributary as it feeds the canal system of the Bhakra Nangal project.”
NCERT Class 11 · India: Physical Environment, Chapter 3 “The Panjnad is the name given to the five rivers of Punjab, namely the Satluj, the Beas, the Ravi, the Chenab and the Jhelum.”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2026 · Q26

Medium Provisional key

Which of the following with reference to Indian States is/are not correct?

1.Uttar Pradesh shares its boundary with the highest number of other Indian States.
2.Rajasthan shares the longest international border among all Indian States.
3.Sikkim is the only State that shares its boundary with just one other Indian State.

Select the answer using the code given below:

Answer & explanation

Answer: (c) 2 and 3

UPSC's key treats statements 2 and 3 as wrong. West Bengal's border with Bangladesh alone is 2,216.7 km (plus borders with Nepal and Bhutan), and Sikkim is not alone in touching a single State: Meghalaya borders only Assam. Uttar Pradesh touches many States (and Delhi), more than any other State.

✓ 1. Uttar Pradesh borders many States and Delhi (Britannica lists Uttarakhand, Bihar, Jharkhand, Chhattisgarh, Madhya Pradesh, Rajasthan, Haryana and Delhi), more than any other State.
✗ 2. UPSC's official key treats this as incorrect. West Bengal's stretch of the India-Bangladesh border alone is 2,216.7 km; we could not confirm Rajasthan's own border length from an official source, so we do not state it.
✗ 3. Sikkim touches only West Bengal among Indian States, but Meghalaya likewise touches only Assam, so Sikkim is not the only such State.

Remember · Longest international border: West Bengal (Bangladesh 2,216.7 km + Nepal + Bhutan). Most neighbouring States: Uttar Pradesh. One-neighbour States: Sikkim (West Bengal), Meghalaya (Assam).

Sources

Ministry of Home Affairs, Annual Report 2023-24, Ch 3 Border Management ↗ “The Indian side of the India- Bangladesh border touches West Bengal (2216.7 km), Assam (263 km), Meghalaya (443 km), Tripura (856 km) … India shares 3323 km of its land border with Pakistan. This border runs along the States of Gujarat, Rajasthan, Punjab, Union Territory of Jammu & Kashmir and Union Territory of Ladakh.”
Encyclopaedia Britannica, Uttar Pradesh ↗ · reference work “Uttar Pradesh is bordered by Uttarakhand and Nepal to the north, Bihar to the east, Jharkhand and Chhattisgarh to the southeast, Madhya Pradesh to the south, and Rajasthan and Haryana and Delhi to the west.”
Encyclopaedia Britannica, Sikkim ↗ · reference work “Sikkim is bordered to the north and northeast by the Tibet Autonomous Region of China, to the southeast by Bhutan, to the south by the Indian state of West Bengal, and to the west by Nepal.”
Encyclopaedia Britannica, Meghalaya ↗ · reference work “It is bordered by Assam to the north and northeast and by Bangladesh to the south and southwest.”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2026 · Q34

Easy Provisional key

Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India?

1.Submergence of parts of the western coast due to tectonic activity
2.Presence of residual mountain ranges such as the Veliconda hills and Mahendragiri hills
3.Deep, V-shaped river valleys formed by fast-flowing rivers

Select the answer using the code given below:

Answer & explanation

Answer: (b) 1 and 2

The Peninsular Block is an ancient, rigid landmass whose western edge has partly sunk beneath the sea and whose hills are old, worn-down remnants such as the Veliconda and Mahendragiri ranges. Its river valleys are shallow, so deep V-shaped valleys belong instead to the young Himalayan mountains.

✓ 1. NCERT describes the Peninsula as a rigid block since the Cambrian, except for part of its western coast that lies submerged beneath the sea, with other parts altered by tectonic activity.
✓ 2. The Peninsula mostly consists of relict and residual mountains, and NCERT lists the Veliconda hills and the Mahendragiri hills among them.
✗ 3. Peninsular river valleys are shallow with low gradients. Gorges and V-shaped valleys are marks of the young, fast-flowing rivers of the Himalayan mountains.

Remember · Peninsular Block: ancient rigid block, submerged western coast, relict and residual hills (Aravali, Nallamala, Veliconda, Mahendragiri), shallow valleys. V-shaped valleys are Himalayan.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 2 (practise this chapter) · Class 11 India: Physical Environment, Ch 2 (practise this chapter) · Class 11 India: Physical Environment, Ch 2 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 2 “Since the Cambrian period, the Peninsula has been standing like a rigid block with the exception of some of its western coast which is submerged beneath the sea and some other parts changed due to tectonic activity”
NCERT Class 11 · India: Physical Environment, Chapter 2 “the Javadi hills, the Veliconda hills, the Palkonda range and the Mahendragiri hills, etc. The river valleys here are shallow with low gradients.”
NCERT Class 11 · India: Physical Environment, Chapter 2 “These mountains are tectonic in origin, dissected by fast-flowing rivers which are in their youthful stage. Various landforms like gorges, V-shaped valleys, rapids, waterfalls, etc. are indicative of this stage.”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2024 · Q6

Medium

With reference to the Himalayan rivers joining the Ganga downstream of Prayagraj from West to East, which one of the following sequences is correct?

Answer & explanation

Answer: (b) Gomati – Ghaghara – Gandak – Kosi

Follow the Ganga eastward from Prayagraj: the Gomati joins first at Kaithi (Ghazipur district, near Varanasi), then the Ghaghara near Chhapra, then the Gandak at Sonpur opposite Patna, and finally the Kosi further east in Bihar.

✓ (b) Gomati (Kaithi, Ghazipur) → Ghaghara (Chhapra) → Gandak (Sonpur, opposite Patna) → Kosi (eastern Bihar) is the west-to-east order of their confluences.
✗ (a) The Ghaghara cannot come first: the Gomati meets the Ganga upstream, near Varanasi, well before Chhapra.
✗ (d) The Kosi basin lies east of the Gandak and Burhi Gandak basins, so the Kosi joins after the Gandak, not before it.

Remember · Left-bank Himalayan tributaries of the Ganga, west to east: Ramganga, Gomati, Ghaghara, Gandak, Kosi, Mahananda.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “The important left bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda.”
Central Water Commission (Upper Ganga Basin Organisation): Gomti Basin ↗ “The river flows through an incised valley southwards through the districts of Sitapur, Lucknow, Barabanki, Sultanpur, and Jaunpur before meeting the Ganga river at Kaithi, District-Ghazipur, bordering Varanasi”
India-WRIS Wiki: Gandak Basin ↗ “The Gandak Basin is bounded on north by the Himalayas. On the south by the River Ganga, On the east by the Burhi Gandak Basin and on the west by the Ghagra Basin.”
India-WRIS Wiki: Kosi Basin ↗ “The Kosi basin is bounded on the north by the Himalayas, on the east by Mahananda basin, on the west by the Burhi Gandak basin and on the south by the river Ganga.”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2024 · Q9

Medium

Consider the following information:

	Waterfall	Region	River
1.	Dhuandhar	Malwa	Narmada
2.	Hundru	Chota Nagpur	Subarnarekha
3.	Gersoppa	Western Ghats	Netravati

In how many of the above rows is the given information correctly matched?

Answer & explanation

Answer: (a) Only one

Only the Hundru row is fully right. Dhuandhar is on the Narmada but near Jabalpur in the Narmada rift valley, not in the Malwa plateau; Gersoppa (Jog) Falls is in the Western Ghats but on the Sharavati, not the Netravati.

✗ 1. Dhuandhar falls is on the Narmada near Jabalpur, where the river flows in a rift valley between the Vindhyas and Satpuras. The Malwa plateau lies to the north of the Narmada valley.
✓ 2. Hundru Falls is on the Subarnarekha river on the Chota Nagpur plateau, near Ranchi.
✗ 3. Gersoppa Falls, better known as Jog Falls, is in the Western Ghats but is formed by the Sharavati river. The Netravati is a different west-flowing river further south.

Remember · Dhuandhar — Narmada, near Jabalpur. Hundru — Subarnarekha, Chota Nagpur. Jog/Gersoppa — Sharavati, Western Ghats.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter) · Class 11 An Introduction to Indian Art, Part I, Ch 8 (practise this chapter) · Class 6 Exploring Society: India and Beyond, Ch 3 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “Flowing in a rift valley between the Satpura in the south and the Vindhyan range in the north, it forms a picturesque gorge in marble rocks and Dhuandhar waterfall near Jabalpur.”
NCERT Class 11 · An Introduction to Indian Art, Part I, Chapter 8 “The city of Mandu is located sixty miles from Indore, at an elevation of over 2000 feet and overlooks the Malwa Plateau to the north and the Narmada valley to the south.”
NCERT Class 6 · Exploring Society: India and Beyond, Chapter 3 “the Hundru Falls on the Subarnarekha River in the Chhota Nagpur Plateau and the Jog Falls on the Sharavati River in the Western Ghats are a few such waterfalls.”
IGNCA (Ministry of Culture): A Glimpse of Karnataka ↗ “Westward rivers: Mandavi, Kalinadi, Gangavali (or Bedti), Sharavati (with Gersoppa Falls), Haladi, Svarna, Netravati.”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q1

Medium

Consider the following statements:

1.Jhelum River passes through Wular Lake.
2.Krishna River directly feeds Kolleru Lake.
3.Meandering of Gandak River formed Kanwar Lake.

How many of the statements given above are correct?

Answer & explanation

Answer: (a) Only one

Only statement 1 holds. The Jhelum flows through Wular Lake, but Kolleru gets its direct inflow from the Budameru and Tammileru streams rather than the Krishna, and Kanwar Lake belongs to the meander belt of the Burhi Gandak, which is a different river from the Gandak.

✓ 1. The Jhelum rises at Verinag, flows past Srinagar and then through Wular Lake before it crosses into Pakistan.
✗ 2. Kolleru lies between the Krishna and Godavari basins, but the rivers feeding it directly are two seasonal streams, the Budameru and the Tammileru, along with about 30 drains and channels.
✗ 3. Kanwar Lake (Kabartal) in Begusarai, Bihar, is part of a wetland complex in the lower reaches of the meandering Burhi Gandak; the Burhi Gandak and the Gandak are separate rivers.

Remember · Wular Lake: Jhelum. Kolleru: fed by Budameru and Tammileru, between Krishna and Godavari deltas. Kanwar/Kabartal: Burhi Gandak meanders, Bihar's first Ramsar site (2020).

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “It flows through Srinagar and the Wular lake before entering Pakistan through a deep narrow gorge.”
Ramsar Information Sheet: Kolleru Lake ↗ “It is fed directly by two seasonal rivers, the Budameru and the Tammileru (East and West branches) besides 30 inflowing drains and channels.”
Ramsar Information Sheet: Kabartal Wetland ↗ “Kabartal is the largest of a complex of 18 interconnected wetlands formed in the lower reaches of River Burhi Gandak.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q5

Medium

Which one of the following is the best example of repeated falls in sea level, giving rise to present-day extensive marshland?

Answer & explanation

Answer: (d) Rann of Kutch

The Rann of Kachchh was once a shallow part of the Arabian Sea. A geological shift closed off its connection with the sea, leaving a vast seasonal marshy salt desert that fills with water in the monsoon and dries into a white salt flat in summer.

✓ (d) The Rann was a shallow part of the Arabian Sea until a geological shift closed its connection with the sea; it is now a huge seasonal marshy salt desert in Gujarat, made up of the Great Rann and the Little Rann.
✗ (a) Bhitarkanika in Odisha is a mangrove forest. NCERT notes that mangroves grow along coasts in salt marshes, tidal creeks, mud flats and estuaries, so it is a coastal tidal wetland, not marshland left behind by a retreating sea.
✗ (b) Marakkanam in Tamil Nadu is known for its coastal salt pans, where salt is made from seawater; these are small human-made works, not a vast natural marshland.

Remember · Rann of Kutch: former shallow part of the Arabian Sea, cut off by a geological shift; now a seasonal marshy salt desert (Great Rann and Little Rann) in Gujarat.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 5 (practise this chapter)

Sources

Encyclopaedia Britannica: Rann of Kachchh ↗ · reference work “The Rann was a once a shallow part of the Arabian Sea , until a geological shift closed off the connection with the sea. The region became a seasonal marshy salt desert over the years. … During the monsoons, the area fills with water, creating a wetland. In the summer, the water evaporates, leaving a white, salty land.”
NCERT Class 11 · India: Physical Environment, Chapter 5 “Mangroves grow along the coasts in the salt marshes, tidal creeks, mud flats and estuaries.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2023 · Q9

Medium

Consider the following statements:

1.Amarkantak Hills are at the confluence of Vindhya and Sahyadri Ranges.
2.Biligirirangan Hills constitute the easternmost part of Satpura Range.
3.Seshachalam Hills constitute the southernmost part of Western Ghats.

How many of the statements given above are correct?

Answer & explanation

Answer: (d) None

Each statement pairs a hill with the wrong range. Amarkantak is where the Vindhya and Satpura (Maikal) ranges meet, the Biligirirangan Hills in southern Karnataka link the Eastern and Western Ghats, and the Seshachalam Hills in Andhra Pradesh belong to the Eastern Ghats.

✗ 1. The Narmada rises on the Amarkantak plateau and flows west between the Satpura to the south and the Vindhya to the north; Amarkantak joins the Vindhya and Satpura systems, while the Sahyadri (Western Ghats) lie far to the south-west.
✗ 2. The Satpura range lies in central India and marks the northern edge of the Deccan plateau; the Biligirirangan Hills are in Chamarajanagar district of southern Karnataka, where the Eastern and Western Ghats come together.
✗ 3. The Seshachalam Hills, home to the Seshachalam Biosphere Reserve and Tirumala, are in Andhra Pradesh and are part of the Eastern Ghats. The southern end of the Western Ghats is formed by the Anaimalai and Cardamom hills of Kerala and Tamil Nadu.

Remember · Amarkantak: Vindhya–Satpura junction, source of Narmada and Son. Biligirirangan: meeting of Eastern and Western Ghats. Seshachalam: Eastern Ghats, Andhra Pradesh.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter) · Class 11 India: Physical Environment, Ch 2 (practise this chapter) · Class 11 India: Physical Environment, Ch 2 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “The Narmada originates on the western flank of the Amarkantak plateau at a height of about 1,057 m. Flowing in a rift valley between the Satpura in the south and the Vindhyan range in the north”
NCERT Class 11 · India: Physical Environment, Chapter 2 “The Satpura range is formed by a series of scarped plateaus on the south, generally at an elevation varying between 600-900 m above the mean sea level. This forms the northernmost boundary of the Deccan plateau.”
NCERT Class 11 · India: Physical Environment, Chapter 2 “Western Ghats are locally known by different names such as Sahyadri in Maharashtra, Nilgiri hills in Karnataka and Tamil Nadu and Anaimalai hills and Cardamom hills in Kerala.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q76

Medium

Consider the following statements:

Statement-I: According to the United Nations' 'World Water Development Report, 2022', India extracts more than a quarter of the world's groundwater withdrawal each year.
Statement-II: India needs to extract more than a quarter of the world's groundwater each year to satisfy the drinking water and sanitation needs of almost 18% of world's population living in its territory.

Which one of the following is correct in respect of the above statements?

Answer & explanation

Answer: (c) Statement-I is correct but Statement-II is incorrect

Statement-I is correct: India is the world's largest user of groundwater, taking more than a quarter of the global total. Statement-II is wrong because most of that water goes to irrigation, not to drinking water and sanitation.

✓ Statement-I India is the largest groundwater user in the world, drawing an estimated 230 cubic kilometres a year, which is over a quarter of the global total.
✗ Statement-II Agriculture accounts for about 92 per cent of India's groundwater use (NCERT); drinking water and other domestic needs take only a small share. The high extraction is driven by irrigation, so the stated reason is false.

Remember · India draws over a quarter of the world's groundwater, but about nine-tenths of it goes to irrigation, not to drinking water and sanitation.

📘 Read it in NCERT: Class 12 India: People and Economy, Ch 4 (practise this chapter)

Sources

NCERT Class 12 · India: People and Economy, Chapter 4 “Agriculture accounts for most of the surface and groundwater utilisation, it accounts for 89 per cent of the surface water and 92 per cent of the groundwater utilisation.”
World Bank: India Groundwater, a Valuable but Diminishing Resource ↗ “India is the largest user of groundwater in the world. It uses an estimated 230 cubic kilometers of groundwater per year - over a quarter of the global total.”
IGRAC (UNESCO-hosted): India groundwater country profile ↗ · reference work “By 2022, groundwater abstraction was distributed as follows: 87% for irrigation (making agriculture the largest consumer). 11% for domestic use. 2% for industrial use.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q24

Easy

Gandikota canyon of South India was created by which one of the following rivers?

Answer & explanation

Answer: (c) Pennar

The Gandikota gorge in Kadapa district, Andhra Pradesh, is cut by the Pennar (Penna) river through the Erramala hills. The name itself joins the Telugu words for gorge ('gandi') and fort ('kota'), after the medieval fort perched above the canyon.

✓ (c) The Kadapa district administration describes the Penna river gorge, about 200 metres wide, flowing between the cliffs of the Erramala hills at Gandikota.
✗ (d) The Tungabhadra is a Krishna tributary flowing past Hampi in Karnataka; it does not flow through Kadapa district.
✗ (b) The Manjira is a tributary of the Godavari in Maharashtra, Karnataka and Telangana, far north of Gandikota.

Remember · Gandikota ('gorge fort'), Kadapa district, Andhra Pradesh: canyon of the Pennar/Penna river through the Erramala hills — often called India's Grand Canyon.

Sources

District YSR (Kadapa), Government of Andhra Pradesh: Gandikota ↗ “The viewpoint offers breathtaking panoramic views of the Penna river gorge flowing between the cliffs of Erramala hills, with a width of around 200 metres, forming one of the finest gorges in South India.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q25

Easy

Consider the following pairs:

	Peak	Mountains
1.	Namcha Barwa	Garhwal Himalaya
2.	Nanda Devi	Kumaon Himalaya
3.	Nokrek	Sikkim Himalaya

Which of the pairs given above is/are correctly matched?

Answer & explanation

Answer: (b) 2 only

Why not the tempting option · The tempting objection is that Nanda Devi stands in Chamoli, in the Garhwal division of Uttarakhand; but 'Kumaon Himalaya' in the regional divisions of the range means the whole stretch between the Satluj and the Kali, which takes in Garhwal, and Nanda Devi is its highest peak.

Only pair 2 is right. In the regional divisions of the Himalaya, the Kumaon Himalaya is the stretch between the Satluj and the Kali, the whole of Uttarakhand including Garhwal, and Nanda Devi (7,816 m) is its highest peak. Namcha Barwa stands at the eastern end of the range, where the Brahmaputra bends round it into Arunachal Pradesh, nowhere near Garhwal; Nokrek is in Meghalaya, not in the Himalaya at all.

✗ 1. Namcha Barwa (7,755 m) is in the eastern Himalaya, at the great bend where the river emerges from the foothills as the Siang or Dihang and enters Arunachal Pradesh. Garhwal is at the other end of the range.
✓ 2. Nanda Devi (7,816 m) is the highest peak of the Kumaon Himalaya. The peak itself stands in Chamoli, in Uttarakhand's Garhwal division, but 'Kumaon Himalaya' in the regional divisions of the range means the whole stretch between the Satluj and the Kali, which takes in Garhwal; NCERT uses this very division.
✗ 3. NCERT lists Nokrek as a biosphere reserve in Meghalaya (1988), in the Garo Hills of the north-east, not in the Sikkim Himalaya.

Remember · Regional divisions of the Himalaya by rivers: Punjab (Indus to Satluj), Kumaon (Satluj to Kali), Nepal (Kali to Teesta), Assam (Teesta to Dihang). Nanda Devi: highest peak of the Kumaon Himalaya, Uttarakhand. Namcha Barwa: eastern end, at the Brahmaputra's bend. Nokrek: Meghalaya.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter) · Class 11 India: Physical Environment, Ch 5 (practise this chapter)

Sources

NCERT Class 9 Contemporary India I, Ch 2 Physical Features of India (Internet Archive copy of the ncert.nic.in PDF, which refuses scripted fetches) ↗ “The part of the Himalayas lying between Satluj and Kali rivers is known as Kumaon Himalayas.”
NCERT Class 11 · India: Physical Environment, Chapter 3 “Himalayas near Namcha Barwa (7,755 m). The river emerges from the foothills under the name of Siang or Dihang. It enters India west of Sadiya town in Arunachal Pradesh.”
Encyclopaedia Britannica: Kumaun Himalayas ↗ · reference work “It rises to 25,646 feet (7,817 metres) at Nanda Devi , the range’s highest peak, and to 25,446 feet (7,756 metres) at Kamet, near the Chinese border.”
NCERT Class 11 · India: Physical Environment, Chapter 5 “2. Nanda Devi 1988 Uttarakhand. 3. Nokrek 1988 Meghalaya. 4. Manas 1989 Assam”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2022 · Q30

Medium

Consider the following pairs:

	Wetland/Lake	Location
1.	Hokera Wetland	Punjab
2.	Renuka Wetland	Himachal Pradesh
3.	Rudrasagar Lake	Tripura
4.	Sasthamkotta Lake	Tamil Nadu

How many pairs given above are correctly matched?

Answer & explanation

Answer: (b) Only two pairs

All four are Ramsar sites. Renuka (Sirmaur, Himachal Pradesh) and Rudrasagar (Melaghar, Tripura) are correctly placed, but Hokera (Hokersar) lies near Srinagar in Jammu and Kashmir, and Sasthamkotta is in Kollam district, Kerala. So only two pairs match.

✗ 1. Hokera, also called Hokersar, is a wetland near Srinagar in the Kashmir valley, a winter halt for migratory birds from Siberia and Central Asia — not in Punjab.
✓ 2. Renuka lake and the Renuka Wildlife Sanctuary around it are in Sirmaur district, Himachal Pradesh.
✓ 3. Rudrasagar Lake is at Melaghar in Sepahijala district, Tripura; the Neermahal water palace stands in the middle of it.
✗ 4. Sasthamkotta (Sasthamcotta) Lake, Kerala's largest freshwater lake, is about 19 km from Kollam town and supplies Kollam's drinking water — it is in Kerala, not Tamil Nadu.

Remember · Hokera/Hokersar — J&K; Renuka — Himachal Pradesh; Rudrasagar (Neermahal) — Tripura; Sasthamkotta — Kerala (largest freshwater lake of the state). All are Ramsar sites.

Sources

District Srinagar (Government of Jammu and Kashmir): About District ↗ “Hokersar is a wetland situated near Srinagar. Thousands of migratory birds come to Hokersar from Siberia and other regions in the winter season.”
District Sirmaur (Government of Himachal Pradesh): Renuka Ji ↗ “Renuka lake is situated in the Sirmour district of Himachal Pradesh in India and it is 672 m above the sea level.”
District Sepahijala (Government of Tripura): Neermahal ↗ “It is situated in Melaghar, 53 kilometers away from the Agartala, the capital of Tripura. The palace is situated in the middle of Rudrasagar Lake”
District Kollam (Government of Kerala): Places of Interest ↗ “Sasthamcottah is an attractive village situated about 19 kms. from Kollam Town. It is a beauty spot, a health resort and a centre of pilgrimage. The extensive freshwater lake here, is said to be the biggest of its kind in Kerala.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q70

Medium

Consider the following pairs:

	Reservoirs	States
1.	Ghataprabha	Telangana
2.	Gandhi Sagar	Madhya Pradesh
3.	Indira Sagar	Andhra Pradesh
4.	Maithon	Chhattisgarh

How many pairs given above are not correctly matched?

Answer & explanation

Answer: (c) Only three pairs

Only Gandhi Sagar (Madhya Pradesh) is correctly matched, so three pairs are wrong. Ghataprabha (Hidkal) is in Karnataka, Indira Sagar is in Madhya Pradesh and Maithon is in Jharkhand.

✗ 1. The Ghataprabha (Hidkal) reservoir is in Karnataka, not Telangana.
✓ 2. Gandhi Sagar is on the Chambal river in Madhya Pradesh.
✗ 3. Indira Sagar is a multipurpose project on the Narmada in Madhya Pradesh, not Andhra Pradesh.
✗ 4. Maithon dam is on the Barakar river near Dhanbad in Jharkhand, not Chhattisgarh.

Remember · Gandhi Sagar (Chambal) and Indira Sagar (Narmada) are in Madhya Pradesh; Maithon (Barakar, DVC) is in Jharkhand; Ghataprabha's Hidkal reservoir is in Karnataka.

Sources

Central Water Commission: Sedimentation assessment of Ghataprabha (Hidkal) reservoir, Karnataka ↗ “SEDIMENTATION ASSESSMENT OF GHATAPRABHA (HIDKAL) RESERVOIR, KARNATAKA, THROUGH SATELLITE REMOTE SENSING”
District Administration Mandsaur (Government of Madhya Pradesh): Gandhi Sagar Dam ↗ “Gandhisagar Dam is situated at a distance of 168 Km. from the District headquarter. The Dam is constructed on the Chambal River.”
District Administration Khandwa (Government of Madhya Pradesh): Indira Sagar ↗ “Indira Sagar Dam is a multipurpose dam project at Madhya Pradesh in Central India. It was built on Narmada river which flows from Central India to Western India.”
District Dhanbad (Government of Jharkhand): Maithon Dam ↗ “It is located on the banks of river Barakar. The Maithon Dam is located about 48 kms from the Coal City of Dhanbad.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2021 · Q53

Medium

With reference to the Indus river system, of the following four rivers, three of them pour into one of them which joins the Indus direct. Among the following, which one is such river that joins the Indus direct?

Answer & explanation

Answer: (d) Sutlej

Why not the tempting option · UPSC's key is (d). The Jhelum and the Ravi join the Chenab, the Chenab empties into the Sutlej, and the Sutlej's lower course, called the Panjnad once the five rivers have united below Uch, joins the Indus near Mithankot. A strict reader may say the Panjnad, not the Sutlej, is what meets the Indus, but the question treats the Panjnad as the Sutlej's continuation, as standard descriptions do. In the exam, follow the order Jhelum and Ravi → Chenab → Sutlej → Indus.

The Sutlej is the river that carries the other three onward to the Indus: the Jhelum and the Ravi join the Chenab, and the Chenab then empties into the Sutlej, whose combined stream (the Panjnad) meets the Indus near Mithankot.

✗ (b) The Jhelum joins the Chenab near Jhang (Trimmu) in Pakistan, so it does not reach the Indus on its own.
✗ (c) The Ravi joins the Chenab near Sarai Sidhu in Pakistan, so it too ends in the Chenab.
✗ (a) The Chenab receives the Jhelum and the Ravi, but it then empties into the Sutlej west of Bahawalpur instead of reaching the Indus directly.
✓ (d) The Sutlej takes in the Beas, receives the Chenab, and its united stream, the Panjnad, links the five Punjab rivers to the Indus near Mithankot.

Remember · Jhelum and Ravi join the Chenab; the Chenab joins the Sutlej; the Sutlej-Chenab stream (the Panjnad) joins the Indus near Mithankot.

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “Before entering Pakistan and joining the Chenab near Sarai Sidhu, it drains the area lying between the southeastern part of the Pir Panjal and the Dhauladhar ranges.”
NCERT Class 11 · India: Physical Environment, Chapter 3 “It flows through Srinagar and the Wular lake before entering Pakistan through a deep narrow gorge. It joins the Chenab near Jhang in Pakistan.”
NCERT Class 11 · India: Physical Environment, Chapter 3 “The river flows southward and receives 'Panjnad' a little above Mithankot. The Panjnad is the name given to the five rivers of Punjab, namely the Satluj, the Beas, the Ravi, the Chenab and the Jhelum.”
Central Water Commission, Indus Basin Organisation: About Basins ↗ “The Indus is the western most River system in the subcontinent. Jhelum, Chenab, Ravi, Beas and Satluj are its main tributaries.”
Encyclopaedia Britannica: Sutlej River ↗ · reference work “to join the Chenab River west of Bahawalpur. The combined rivers then form the Panjnad, the link between the Five Rivers and the Indus.”
Encyclopaedia Britannica: Chenab River ↗ · reference work “After receiving the Jhelum River near Trimmu, the Chenab empties into the Sutlej River, a tributary of the Indus River.”

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2021 · Q54

Medium

With reference to India, Didwana, Kuchaman, Sargol and Khatu are the names of

Answer & explanation

Answer: (d) saline lakes

Didwana, Kuchaman, Sargol and Khatu are saline (salt) lakes in the dry interior of Rajasthan, in the Nagaur-Sikar region. They fill briefly after rain and leave salt behind as the water evaporates.

✓ (d) These are inland salt lakes of the Thar and Shekhawati region. Didwana is a known playa lake in Nagaur district, and Kuchaman is one of Rajasthan's salt works that draw on lake brine, like Sambhar.
✗ (a) Glaciers are found only in high mountain regions such as the Himalaya; Rajasthan has none.
✗ (b) Mangroves grow on tidal coasts and river deltas, while these lakes lie hundreds of kilometres inland in a desert region.
✗ (c) Sambhar is Rajasthan's famous saline Ramsar site, but these four lakes are not on the Ramsar list.

Remember · Rajasthan's inland salt lakes: Sambhar (largest), Didwana, Kuchaman, Sargol, Khatu, Pachpadra. Playas collect run-off, then evaporation leaves salt.

Sources

Office of the Salt Commissioner, Government of India: Salt industry in India ↗ “Inland Salt Works in Rajasthan using lake brine and sub-soil brine viz. Sambhar Lake, Nawa, Rajas, Kuchhaman, Sujangarh and Phalodi”
ICAR-Central Arid Zone Research Institute: Playa lakes of western Rajasthan (Annals of Arid Zone) ↗ · reference work “Salts and evaporites brought by run-off from surrounding catchments during rains accumulate in these sites.”
Rajasthan Tourism / Environment Dept: Wetland inventory, Nagaur district (salt pans) ↗ “1204 Salt pans Khatu Salt Lake NAGAUR DIDWANA”

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2021 · Q55

Hard

Consider the following rivers:

1.Brahmani
2.Nagavali
3.Subarnarekha
4.Vamsadhara

Which of the above rise from the Eastern Ghats?

Answer & explanation

Answer: (b) 2 and 4

The Nagavali and the Vamsadhara both rise in the Eastern Ghats of Odisha, so 2 and 4 is right. The Brahmani and the Subarnarekha, by contrast, start near Nagri village in Ranchi district on the Chota Nagpur plateau of Jharkhand.

✗ 1. The Brahmani, known as the South Koel in its upper reaches, originates near Nagri village in Ranchi district, Jharkhand, at about 600 m.
✓ 2. The Nagavali rises in the Eastern Ghats (near Lakhabahal in Kalahandi district, Odisha) and reaches the Bay of Bengal near Srikakulam in Andhra Pradesh.
✗ 3. The Subarnarekha also rises near Nagri village in Ranchi district, Jharkhand, at about 600 m elevation, and flows about 395 km to the Bay of Bengal.
✓ 4. The Vamsadhara rises in the Eastern Ghats of Odisha and falls into the Bay of Bengal near Kalingapatnam in Andhra Pradesh.

Remember · Nagavali and Vamsadhara start in the Eastern Ghats; Brahmani (South Koel) and Subarnarekha both start near Nagri, Ranchi, on the Chota Nagpur plateau.

Sources

Srikakulam District (Government of Andhra Pradesh): History ↗ “The Vamsadhara river rises in the Eastern Ghats of Orissa State and enters Srikakulam District in Bhamini Mandal and finally falls into the Bay of Bengal near Kalingapatnam.”
Srikakulam District (Government of Andhra Pradesh): About District ↗ “The Nagavali and Suvarnamukhi rivers also originate in the Eastern Ghats while Nagavali in Vangara Mandal”
India-WRIS (Ministry of Jal Shakti): Subarnarekha ↗ “It originates near Nagri village in Ranchi district of Jharkhand at an elevation of 600 m. The total length of the river is about 395 km.”
India-WRIS (Ministry of Jal Shakti): Brahmani ↗ “The Brahmani, known as the South Koel river in the upper reaches, originates near Nagri village in Ranchi district of Jharkhand at an elevation of about 600m.”

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2020 · Q73

Medium

Which of the following Protected Areas are located in Cauvery basin?

1.Nagarhole National Park
2.Papikonda National Park
3.Sathyamangalam Tiger Reserve
4.Wayanad Wildlife Sanctuary

Select the correct answer using the code given below:

Answer & explanation

Answer: (c) 1, 3 and 4 only

Nagarhole, Sathyamangalam and Wayanad are all drained by the Kaveri (Cauvery) and its tributaries, but Papikonda National Park lies along the Godavari in Andhra Pradesh, so 2 is the only one that does not belong.

✓ 1. Nagarhole's own stream, the Nagarahole, joins the Kabini, and the Kabini is a right-bank tributary of the Kaveri.
✗ 2. Papikonda National Park is in the Papi Hills of Andhra Pradesh, where the Godavari cuts through the range; it belongs to the Godavari basin, not the Cauvery.
✓ 3. Sathyamangalam Tiger Reserve in Erode district (Tamil Nadu) is drained by the Bhavani, Moyar and Suvarnavathi, which are Kaveri tributaries.
✓ 4. Wayanad Wildlife Sanctuary in Kerala is drained by the Kabini, which rises in Wayanad and joins the Kaveri in Karnataka.

Remember · Nagarhole, Wayanad and Sathyamangalam sit in the Kabini-Bhavani part of the Cauvery basin; Papikonda sits on the Godavari.

Sources

NTCA brief note: Nagarahole Tiger Reserve ↗ “The reserve is named after a small river ‘Nagarahole’ (literally a snake stream in Kannada), which meanders within the habitat, before joining the river Kabini.”
Inland Waterways Authority of India, Detailed Project Report: Kabini River (NW-51) ↗ “Kabini River originates from the Pakramthalam hills (Western Ghat) in Wayanad district of Kerala state at an altitude of about 2140m. It flows eastward to join the Kaveri River at Tirumakudalu Narasipura in Karnataka”
Sathyamangalam Tiger Reserve (Government of Tamil Nadu), Tiger Conservation Plan: Core Zone ↗ “Major Streams Swarnavathi & Halibidha Halla are the major streams. The Suvarnavathi is one of the Southern tributaries of the R. Kaveri.”
Papikondalu, Eluru District (Government of Andhra Pradesh) ↗ “Papikondalu Mountain range runs along River Godavari, one of the largest and vivacious rivers in India.”
Kerala Tourism (Government of Kerala), Wayanad Wildlife Sanctuary ↗ · reference work “Rivers like the Kabini, Cherupuzha, and Bavali flow through the sanctuary, enhancing its scenic beauty and providing essential water sources for its flora and fauna.”

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2020 · Q96

Medium

Siachen Glacier is situated to the

Answer & explanation

Answer: (d) North of Nubra Valley

Siachen Glacier lies in the eastern Karakoram range, up the Nubra Valley of Ladakh, so it is north of the Nubra Valley. It is not east of Leh, east of Aksai Chin or north of Gilgit.

✓ (d) The Nubra Valley runs up towards the Siachen Glacier, which sits at its head in the eastern Karakoram; the glacier is therefore north of the valley.
✗ (b) Siachen is north of Leh, across the Ladakh range and the Nubra and Shyok valleys, not to its east.
✗ (c) Gilgit lies to the west of the Karakoram range, so Siachen is south-east of Gilgit, not north of it.
✗ (a) Aksai Chin is on the plateau to the east of the Karakoram, so Siachen lies west of it.

Remember · Siachen Glacier: eastern Karakoram, at the head of the Nubra Valley, Ladakh; the Nubra River begins from its snout.

Sources

District Leh, Ladakh (leh.nic.in): Nubra Valley ↗ “Siachen Glacier lies way up in the Nubra Valley and has been thrown open for domestic tourists recently but only until the base camp.”

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2020 · Q98

Hard

Consider the following statements:

1.36% of India's districts are classified as “overexploited” or “critical” by the Central Ground Water Authority (CGWA).
2.CGWA was formed under the Environment (Protection) Act.
3.India has the largest area under groundwater irrigation in the world.

Which of the statements given above is/are correct?

Answer & explanation

Answer: (b) 2 and 3 only

Why not the tempting option · UPSC's key is (b). Statement 1 looks plausible because 256 of India's roughly 720 districts (about 36%) were chosen as 'water stressed' for Jal Shakti Abhiyan in 2019, but those are districts holding at least one stressed block, picked by the Ministry for a campaign; the official 'overexploited' and 'critical' labels are given to blocks, not districts, by the Central Ground Water Board, not the Authority, and cover about 22% of blocks. In the exam, check the unit (block or district) and the body (CGWB assesses, CGWA regulates) before accepting a statistic.

Statements 2 and 3 are correct. CGWA was constituted in January 1997 under Section 3(3) of the Environment (Protection) Act, 1986, and India, the world's largest user of groundwater, has the largest groundwater-irrigated area. Statement 1 fails on every count: groundwater status is assessed for blocks (assessment units), not districts; the assessing body is the Central Ground Water Board, not the Authority; and the stressed share is nowhere near 36%.

✗ 1. The Central Ground Water Board, with the states, classifies assessment units — blocks, mandals, talukas — not districts, and the CGWA is a regulator, not the assessing body. In the 2017 assessment about 17% of units were overexploited and 5% critical, roughly 22% in all. The 36% figure resembles the 256 'water stressed' districts (of about 720) chosen for Jal Shakti Abhiyan in 2019 — districts holding at least one stressed block, a different count made by a different body.
✓ 2. On the direction of the Supreme Court, CGWA was constituted in January 1997 under sub-section (3) of Section 3 of the Environment (Protection) Act, 1986, to regulate groundwater development.
✓ 3. Groundwater provides about 60 per cent of India's irrigation water and over 80 per cent of its domestic supply, making India the world's largest user of groundwater. The area irrigated from it has grown to more than 35 million hectares — the largest groundwater-irrigated area of any country.

Remember · CGWA: set up January 1997 under Section 3(3), Environment (Protection) Act, 1986. India is the world's largest groundwater user; overexploited/critical labels apply to blocks (by CGWB), not districts.

Sources

Central Ground Water Board, Ground Water Regulation ↗ “Central Ground Water Authority (CGWA) constituted in January 1997 under sub-section (3) of Section 3 of the Environment Protection Act, 1986 as per direction of Hon’ble Supreme Court of India”
PIB, Ministry of Finance: World Bank project to improve groundwater management (Atal Bhujal Yojana signing) ↗ “Groundwater currently provides approximately 60 percent of irrigation water. Over 80 percent of the rural and urban domestic water supplies in India are served by groundwater making India the world’s largest user of groundwater.”
World Bank Group Independent Evaluation Group blog: CGWB status of groundwater blocks ↗ · reference work “The Central Groundwater Board of India estimates that about 17% of groundwater blocks are overexploited”
PIB, Ministry of Jal Shakti: Jal Shakti Abhiyan (21 Jul 2022) ↗ “Jal Shakti Abhiyan -I (JSA-I) was launched in 2019 in 1592 blocks in 256 water stressed districts of the country”

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2019 · Q23

Easy

Consider the following pairs:

	Famous place	River
1.	Pandharpur	Chandrabhaga
2.	Tiruchirappalli	Cauvery
3.	Hampi	Malaprabha

Which of the pairs given above are correctly matched?

Answer & explanation

Answer: (a) 1 and 2 only

Pandharpur stands on the Chandrabhaga, the local name of the Bhima, and Tiruchirappalli on the Cauvery (Kaveri). Hampi, the ruins of Vijayanagara, lies on the Tungabhadra, not the Malaprabha, so pair 3 is wrong.

✓ 1. The Solapur district administration notes that the Chandrabhaga (Bhima) flows through Pandharpur, home of the Vitthal (Vithoba) temple and the annual wari pilgrimage.
✓ 2. Tiruchirappalli, the old Chola stronghold with the Srirangam temple on a river island, lies on the banks of the Kaveri.
✗ 3. Vijayanagara (Hampi) was built in the natural basin of the Tungabhadra; the Malaprabha flows past Aihole, Pattadakal and Badami's region further north-west.

Remember · Pandharpur — Bhima (Chandrabhaga); Tiruchirappalli/Srirangam — Kaveri; Hampi — Tungabhadra; Aihole–Pattadakal — Malaprabha.

📘 Read it in NCERT: Class 12 Themes in Indian History, Part II, Ch 3 (practise this chapter)

Sources

Solapur District Administration: Pandharpur ↗ “The Chandrabhaga (Bhima) river flows through the City. Large number of devotees from all over Maharashtra and surrounding States gather at Pandharpur”
Tiruchirappalli District Administration: History ↗ “Situated on the banks of river Kaveri, Tiruchirappalli, the fourth largest city in the state was a citadel of the Early Cholas”
NCERT Class 12 · Themes in Indian History, Part II, Chapter 3 “The most striking feature about the location of Vijayanagara is the natural basin formed by the river Tungabhadra which flows in a north-easterly direction.”

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2019 · Q38

Medium

Consider the following pairs:

	Glacier	River
1.	Bandarpunch	Yamuna
2.	Bara Shigri	Chenab
3.	Milam	Mandakini
4.	Siachen	Nubra
5.	Zemu	Manas

Which of the pairs given above are correctly matched?

Answer & explanation

Answer: (a) 1, 2 and 4

Pairs 1, 2 and 4 are correct: the Yamuna rises from the Bandarpunch glacier area, Bara Shigri feeds the Chandra (which becomes the Chenab), and the Siachen glacier gives rise to the Nubra. Milam is the source of the Sarda, not the Mandakini, and Zemu feeds the Teesta, not the Manas.

✓ 1. The Yamuna has its source in the Yamunotri glacier on the western slopes of the Banderpunch range (spelt Bandarpunch in the question).
✓ 2. Bara Shigri, the largest glacier of Lahaul, lies on the left bank of the Chandra; the Chandra and the Bhaga join at Tandi to form the Chandrabhaga, i.e. the Chenab.
✗ 3. The Milam glacier gives rise to the Sarda (Goriganga), a tributary of the Ghaghara. The Mandakini is a different stream of the Alaknanda system, so this pair fails.
✓ 4. The Siachen glacier is the source of the Nubra river, a tributary of the Shyok, which in turn joins the Indus.
✗ 5. The Zemu glacier on the eastern side of Kanchenjunga in Sikkim feeds the Zemu Chu, a stream of the Teesta basin. The Manas is a different river, a tributary of the Brahmaputra that flows through Bhutan and Assam.

Remember · Bandarpunch feeds the Yamuna, Bara Shigri the Chandra-Chenab, Siachen the Nubra, Milam the Sarda and Zemu the Teesta.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 3 (practise this chapter) · Class 11 India: Physical Environment, Ch 3 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 3 “The Yamuna, the western most and the longest tributary of the Ganga, has its source in the Yamunotri glacier on the western slopes of Banderpunch range (6,316 m).”
NCERT Class 11 · India: Physical Environment, Chapter 3 “The Sarda or Saryu river rises in the Milam glacier in the Nepal Himalayas where it is known as the Goriganga.”
Glaciers, District Lahaul and Spiti, Government of Himachal Pradesh ↗ “After their, confluence at Tandi, their combined waters constitute the Chandrabhaga or the Chenab river. … Shigri is applied par-excellence to one particular glacier that emerges from the mountains on the left bank of the Chandra.”
Siachen Glacier, NASA Earth Observatory ↗ “it is the source of the Nubra River, a tributary of the Indus River flowing into Pakistan and the Arabian Sea.”
Water Sources and Drainage, Gangtok District, Government of Sikkim ↗ “The Teesta comes out as a snout from the Zemu glacier above Lachen Gompha.”

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2019 · Q42

Medium

What is common to the places known as Aliyar, Isapur and Kangsabati?

Answer & explanation

Answer: (d) Water reservoirs

Aliyar, Isapur and Kangsabati are all water reservoirs behind dams: Aliyar in Tamil Nadu, Isapur on the Penganga in Maharashtra and Kangsabati in West Bengal. Each stores water mainly for irrigation.

✓ (d) Aliyar reservoir (Parambikulam-Aliyar Project) is in Tamil Nadu, the Isapur dam is on the Penganga river in Yavatmal district of Maharashtra, and the Kangsabati Reservoir Project irrigates Bankura, Midnapore and Hooghly in West Bengal.
✗ (a) These places are known for dams and irrigation reservoirs, not for mining.
✗ (b) The three sites lie in three different states and are known for their dams, not for tropical rain forest.

Remember · Aliyar (Tamil Nadu), Isapur (Maharashtra) and Kangsabati (West Bengal) are all dam reservoirs.

Sources

Parambikulam Aliyar sub basin, IAMWARM project report, Water Resources Department, Government of Tamil Nadu ↗ “Apart from its own catchments, water can be diverted to this reservoir through the Aliyar Feeder canal and the Contour canal from the Parambikulam group of reservoirs.”
Sedimentation assessment of Isapur reservoir, Maharashtra, Central Water Commission (2021) ↗ “Isapur dam was constructed in the year 1983 on the river Penganga in Pusad Taluk of Yeotmal district in Maharashtra.”
Kangsabati Reservoir Project, Irrigation and Waterways Department, Government of West Bengal ↗ “Kangsabati Reservoir Project was started in the year 1956-57. Till date an irrigation potential of 3,48,477 ha. has been created in the districts of Bankura, Midnapore and Hooghly through this Project.”

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2018 · Q29

Medium

Among the following cities, which one lies on a longitude closest to that of Delhi?

Answer & explanation

Answer: (a) Bengaluru

Bengaluru lies at about 77.6 degrees east, only about 0.4 degrees from Delhi at 77.2 degrees east, so it is the closest in longitude. Hyderabad, Nagpur and Pune lie further east or west of that line.

✓ (a) Delhi is at 77.20 E and Bengaluru at 77.58 E, a gap of about 0.4 degrees. Bengaluru is almost directly south of Delhi.
✗ (b) Hyderabad is at 78.47 E, about 1.3 degrees east of Delhi.
✗ (c) Nagpur is at 79.12 E, about 1.9 degrees east of Delhi.
✗ (d) Pune is at 73.85 E, about 3.4 degrees west of Delhi, the farthest of the four.

Remember · Delhi (77.2 E) and Bengaluru (77.6 E) are almost on the same meridian; Pune (73.9 E) is well to the west.

Sources

India Meteorological Department, sunrise-sunset table for Delhi ↗ “Location: Delhi Longitude : 77.20 E Latitude : 28.58 N”
India Meteorological Department, sunrise-sunset table for Bangalore (Bengaluru) ↗ “Location: Bangalore Longitude : 77.58 E Latitude : 12.97 N”
India Meteorological Department, sunrise-sunset table for Hyderabad ↗ “Location: Hyderabad Longitude : 78.47 E Latitude : 17.45 N”
India Meteorological Department, sunrise-sunset table for Nagpur ↗ “Location: Nagpur Longitude : 79.12 E Latitude : 21.15 N”
India Meteorological Department, sunrise-sunset table for Pune ↗ “Location: Pune Longitude : 73.85 E Latitude : 18.53 N”

Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2018 · Q77

Medium

Which one of the following is an artificial lake?

Answer & explanation

Answer: (a) Kodaikanal (Tamil Nadu)

Kodaikanal Lake is the artificial one: it is a star-shaped lake dug in 1863 in the hill town of Kodaikanal, Tamil Nadu. Kolleru and Renuka are described as natural in their Ramsar information sheets, and the district administration lists Nainital's Naini Lake under natural scenic beauty, with no source calling it man-made.

✓ (a) Tamil Nadu Tourism describes it as a star-shaped artificial lake, built in 1863 under the Collector of Madurai, Sir Vere Henry Levinge.
✗ (b) The Ramsar information sheet calls Kolleru a natural eutrophic lake between the Godavari and Krishna river basins, working as a natural flood-balancing reservoir.
✗ (c) The Nainital district administration lists Naini Lake under 'Natural / Scenic beauty' and notes that the Skanda Purana already refers to Nainital as Tri-Rishi-Sarovar; none of the sources describes it as built. Since Kodaikanal is the artificial lake, this option does not fit.
✗ (d) The Ramsar information sheet describes Renuka as a natural wetland in the Western Himalayas that has survived natural calamities and tectonic upheavals.

Remember · Kodaikanal Lake (TN) is man-made (1863); Kolleru and Renuka are natural wetlands (Ramsar sheets), and Naini Lake is listed as natural scenic beauty.

Sources

Tamil Nadu Tourism: Kodaikanal Lake ↗ “The star-shaped artificial lake, with a depth of 3 meters, was built in 1863 under the stewardship of the Collector of Madurai, Sir Vere Henry Levinge.”
Ramsar Sites Information Service: Information Sheet on Kolleru Lake ↗ “Lake Kolleru, a natural eutrophic lake, situated between the two major river basins of the Godavari and the Krishna.”
Ramsar Sites Information Service: Information Sheet on Renuka Wetland ↗ “Renuka is a natural wetland located in the Western Himalayas which has survived through natural calamities & tectonic upheavals struck during the geological past.”
District Nainital, Government of Uttarakhand: History ↗ “Nainital is referred to in the ‘Manas Khand’ of the ‘Skanda Purana’ as the Tri-Rishi-Sarovar”
District Nainital, Government of Uttarakhand: Naini Lake (tourist category) ↗ “Naini Lake Category Adventure, Natural / Scenic beauty The nucleus of Nainital’s exquisite beauty is beautiful lake”

Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2018 · Q81

Medium

Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds?

1.Decreased salinity in the river
2.Pollution of groundwater
3.Lowering of the water-table

Select the correct answer using the code given below:

Answer & explanation

Answer: (b) 2 and 3 only

Heavy sand mining harms groundwater in two ways: it can pollute it and it can pull the water-table down. It does not lower river salinity; near the coast it makes salt-water intrusion more likely.

✗ 1. Removing sand deepens the channel and weakens natural barriers, so salt water can enter aquifers; UNEP lists 'salination of aquifers' as a result of sand extraction. Salinity goes up, not down.
✓ 2. The sand layer filters water that seeps into the ground. The MoEFCC guidelines say mining can pollute groundwater by thinning this filter material, especially over recharge fissures.
✓ 3. Mining lowers the riverbed and river level, and groundwater in the adjoining flood plain drains towards it, so the water-table falls. The guidelines record this as a listed effect.

Remember · Heavy riverbed sand mining lowers the water-table, weakens the sand filter that protects groundwater, and raises salt intrusion risk near the coast.

Sources

Sustainable Sand Mining Management Guidelines, 2016, MoEFCC (effects of sand and gravel mining) ↗ “Lowering of ground water table in the flood plain because of lowering of riverbed level as well as river water level takes place because of extraction and draining out of excessive ground water from the adjacent areas. … Polluting ground water by reducing the thickness of the filter material especially if mining is taking place at top of recharge fissures.”
Our use of sand brings us 'up against the wall', says UNEP report (UNEP press release) ↗ “Extracting sand where it plays an active role, such as rivers, and coastal or marine ecosystems, can lead to erosion, salination of aquifers, loss of protection against storm surges and impacts on biodiversity”

Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2018 · Q85

Easy

Consider the following statements:

1.The Barren Island volcano is an active volcano located in the Indian territory.
2.Barren Island lies about 140 km east of Great Nicobar.
3.The last time the Barren Island volcano erupted was in 1991 and it has remained inactive since then.

Which of the statements given above is/are correct?

Answer & explanation

Answer: (a) 1 only

Only statement 1 is correct: Barren Island, in the Andaman Sea, is India's only active volcano. It lies north-east of Port Blair, not east of Great Nicobar, and it has erupted again after 1991, most recently in 2017 as of the exam.

✓ 1. NCERT calls Barren Island, in the Andaman and Nicobar Islands, the only active volcano in India.
✗ 2. The island is about 138 km north-east of Port Blair (now Sri Vijaya Puram), the capital of the Andaman and Nicobar Islands. Great Nicobar is at the far southern end of the island chain, much farther away.
✗ 3. The volcano did not stay quiet after 1991; the Ministry of Tourism's page says it last erupted in 2017.

Remember · Barren Island, about 138 km north-east of Port Blair, is India's only active volcano and has erupted as recently as 2017.

📘 Read it in NCERT: Class 11 India: Physical Environment, Ch 2 (practise this chapter)

Sources

NCERT Class 11 · India: Physical Environment, Chapter 2 “Barren island, the only active volcano in India is also situated in the Andaman and Nicobar islands.”
Barren Island, Incredible India (Ministry of Tourism, Government of India) ↗ “Barren Island is approximately 138 kilometres northeast of Sri Vijaya Puram, the capital city of the Andaman and Nicobar Islands. It is renowned for being South Asia's only active volcano, which last erupted in 2017.”

Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2017 · Q4

Medium

From the ecological point of view, which one of the following assumes importance in being a good link between the Eastern Ghats and the Western Ghats?

Answer & explanation

Answer: (a) Sathyamangalam Tiger Reserve

Sathyamangalam, in the Erode region of western Tamil Nadu, sits where the Western Ghats meet the Eastern Ghats. Its forests form a corridor that lets tigers, elephants and other wildlife move between the two hill systems; it became a tiger reserve in 2013.

✓ (a) The reserve's own management describes it as the vital corridor linking the Western and Eastern Ghats, which keeps wildlife populations of the two ranges connected.
✗ (c) Nagarhole in Karnataka is a Western Ghats park; it does not reach the Eastern Ghats.
✗ (d) Seshachalam, around Tirupati in Andhra Pradesh, is an Eastern Ghats biosphere reserve with no link to the Western Ghats.

Remember · Sathyamangalam Tiger Reserve (Tamil Nadu, 2013) is the junction and wildlife corridor between the Western and Eastern Ghats, within the Nilgiri landscape.

Sources

Sathyamangalam Tiger Reserve, Tamil Nadu Forest Department (official site) ↗ “Born from the vision to protect the vital corridor linking the Western and Eastern Ghats, Sathyamangalam Tiger Reserve stands as a triumph of conservation science and community partnership”

Question and answer: UPSC's official GS Paper I (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2017 · Q19

Easy

At one of the places in India, if you stand on the seashore and watch the sea, you will find that the sea water recedes from the shore line a few kilometres and comes back to the shore, twice a day, and you can actually walk on the sea floor when the water recedes. This unique phenomenon is seen at

Answer & explanation

Answer: (c) Chandipur

Chandipur, on the Bay of Bengal coast in Balasore district of Odisha, has a very gently sloping shore: at low tide the sea pulls back up to about 5 km, so visitors can walk on the exposed sea bed, and the water returns with the high tide.

✓ (c) Odisha Tourism calls Chandipur a 'hide and seek' beach: at each low tide it recedes up to about 5 km, exposing the sea bed, and the sea comes back at high tide (tides come roughly twice a day).
✗ (a) Bhavnagar is a port city on the Gulf of Khambhat in Gujarat; it is not the beach known for this walk-on-the-sea-floor phenomenon.
✗ (b) Bheemunipatnam is a coastal town near Visakhapatnam in Andhra Pradesh with an ordinary beach, not a receding one.

Remember · Chandipur (Balasore, Odisha) = the 'vanishing sea' beach: at low tide the sea recedes up to about 5 km and you can walk on the sea bed.

Sources

Odisha Tourism (Government of Odisha): Chandipur ↗ “Chandipur is a beach like no other. During low tides the beach recedes upto 5 KM offering visitors the opportunity to walk on the sea bed.”

Question and answer: UPSC's official GS Paper I (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

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