India — location and physiography

Why it matters

Before you can understand India's rivers, climate, soils or crops, you need a mental map: where India sits on the globe and what shape its land takes. "Location" means India's position by latitude, longitude and neighbours. "Physiography" means the major landforms — mountains, plains, plateaus, deserts, coasts and islands — and how they were formed.

In the Constable paper, Indian Geography questions are mostly short fact-based MCQs: the latitude that cuts India in half, the southernmost point, the highest peak, the difference between Bhabar and Terai, or which coast has deltas. These are among the fastest marks in the paper — if your facts are clean. This lesson builds that clean base.

Core concept

Level 1 — India on the globe

• India lies entirely in the Northern Hemisphere (north of the Equator) and in the Eastern Hemisphere (east of the Prime Meridian).
• The mainland stretches from 8°4′N to 37°6′N latitude and from 68°7′E to 97°25′E longitude. Both spreads are roughly 30°.
• Area: about 3.28 million sq km (32.8 lakh sq km), which is about 2.4% of the world's land area. India is the 7th largest country by area (after Russia, Canada, USA, China, Brazil and Australia).
• North–south length is about 3,214 km; east–west width is about 2,933 km.

Why is the east–west width smaller when both spreads are about 30°? Lines of longitude meet at the poles, so the gap between two longitudes shrinks as you move away from the Equator. Lines of latitude are always the same distance apart. So 30° of latitude covers more ground than 30° of longitude at India's position.

Level 2 — Two special lines

Tropic of Cancer (23°30′N) passes through the middle of India and divides it into two almost equal halves. It crosses 8 states, west to east: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram.

Standard Meridian (82°30′E) is the line on which Indian Standard Time (IST) is based. It passes near Mirzapur in Uttar Pradesh and crosses five states: Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Odisha and Andhra Pradesh.

Why IST is 5 h 30 min ahead of GMT: The Earth turns 360° in 24 hours, so each 1° of longitude equals 4 minutes of time. 82.5° × 4 = 330 minutes = 5 hours 30 minutes.

Why India needs one standard time: From Gujarat (about 68°E) to Arunachal Pradesh (about 97°E) is nearly 30° of longitude, which means about 2 hours of difference in local (sun) time. One common clock avoids confusion in trains, offices and broadcasts.

Level 3 — Extreme points and neighbours

Direction	Extreme point	Where
North	Indira Col	Siachen area, Ladakh
South (whole country)	Indira Point	Great Nicobar Island
South (mainland)	Kanyakumari (Cape Comorin)	Tamil Nadu
East	Kibithu	Arunachal Pradesh
West	Guhar Moti	Kutch, Gujarat

Land neighbours (7): Pakistan and Afghanistan (north-west), China, Nepal and Bhutan (north), Bangladesh and Myanmar (east). India's longest land border is with Bangladesh; the shortest is with Afghanistan.

Sea neighbours: Sri Lanka is separated from India by the Palk Strait and the Gulf of Mannar. Maldives lies to the south-west of Lakshadweep.

Frontier and coast: The land frontier is about 15,200 km. The coastline, including the island groups, has long been quoted as 7,516.6 km (mainland alone about 6,100 km). As of 2025, a Survey of India re-measurement using a finer method puts it at about 11,099 km; pick whichever figure appears in the options.

Why location matters: India sits at the centre of the eastern hemisphere, between East Asia and West Asia, with a long coast on the Indian Ocean — the only ocean named after a country.

Level 4 — The six physiographic divisions

India's landforms are explained by plate tectonics. The Peninsula was part of the ancient southern landmass Gondwana. The Indian plate drifted north and collided with the Eurasian plate. Sediments of the Tethys Sea between them were squeezed and folded upward to form the Himalayas. The deep depression in front of the rising mountains was slowly filled by river sediment to form the Northern Plains.

That gives six divisions:

1. The Himalayan Mountains
2. The Northern Plains
3. The Peninsular Plateau
4. The Indian Desert
5. The Coastal Plains
6. The Islands

1. The Himalayas — young fold mountains

They run about 2,400 km from the Indus in the west to the Brahmaputra in the east. Width is about 400 km in Kashmir and about 150 km in Arunachal Pradesh. Three parallel ranges, north to south:

Range	Other name	Key facts
Himadri	Great / Inner Himalaya	Highest; average height about 6,000 m; snow-bound; has the tallest peaks
Himachal	Lesser Himalaya	3,700–4,500 m; Pir Panjal, Dhaula Dhar, Mahabharat ranges; Kashmir, Kangra and Kullu valleys; hill stations like Shimla, Mussoorie, Nainital
Shiwalik	Outer Himalaya	900–1,100 m; made of loose river sediments; long valleys called Duns lie between Himachal and Shiwalik (Dehradun, Kotli Dun, Patli Dun)

In the east, the hills that turn south along the Myanmar border are called the Purvachal (Patkai hills, Naga hills, Manipur hills, Mizo hills).

Highest peaks: Mount Everest (about 8,849 m) is on the Nepal–China border, not in India. K2 / Godwin Austen (8,611 m) in the Karakoram lies in Indian territory under Pakistan's occupation. Kangchenjunga (8,586 m) in Sikkim is the highest peak in India-administered territory.

2. The Northern Plains — the alluvial gift of rivers

Formed by the Indus, Ganga and Brahmaputra systems, they cover about 7 lakh sq km. Three parts: the Punjab plains (west, Indus system, full of doabs — "do" = two, "ab" = water, land between two rivers), the Ganga plain, and the Brahmaputra plain in Assam (home to Majuli, one of the largest river islands in the world).

Relief changes as you move from the foothills towards the river:

Belt	Description
Bhabar	Narrow belt (8–16 km) at the foot of the Shiwaliks; pebbles and boulders; streams disappear underground
Terai	South of Bhabar; streams re-emerge; wet, swampy, thick forest and wildlife
Bhangar	Older alluvium; higher land above flood level; contains lime nodules called kankar
Khadar	Newer alluvium on floodplains; renewed almost every year; most fertile

3. The Peninsular Plateau — the oldest block

Old crystalline, igneous and metamorphic rocks, part of Gondwana. The Narmada divides it into two parts:

• Central Highlands (north of the Narmada): Malwa plateau; bounded by the Vindhyas in the south and the Aravallis in the north-west. Rivers here (Chambal, Sind, Betwa, Ken) flow from south-west to north-east. Eastern extensions: Bundelkhand, Baghelkhand and the Chotanagpur plateau (drained by the Damodar).
• Deccan Plateau (south of the Narmada): triangular; the Satpura range forms its northern edge; it slopes gently eastward, which is why most peninsular rivers flow into the Bay of Bengal. A north-east extension forms the Meghalaya plateau (Garo, Khasi, Jaintia hills) and the Karbi Anglong plateau. The north-west Deccan has the Deccan Traps — lava-formed rock that weathers into black soil.

Feature	Western Ghats	Eastern Ghats
Continuity	Continuous; crossed only through passes (Thal, Bhor, Pal ghats)	Broken by rivers flowing to the Bay of Bengal
Height	Higher, about 900–1,600 m	Lower, about 600 m on average

Anai Mudi (2,695 m, Kerala) in the Western Ghats is the highest peak of peninsular India; Doda Betta (2,637 m) is the highest in the Nilgiris, where the two Ghats meet. The Aravallis are among the oldest fold mountains in the world; their highest point is Guru Shikhar at Mount Abu.

4. The Indian Desert

Lies west of the Aravallis. A sandy plain with dunes; rainfall below 150 mm a year. Crescent-shaped dunes called barchans cover large areas. The Luni is the only large river.

5. The Coastal Plains

• Western coast (between Western Ghats and Arabian Sea): narrow. North to south: Konkan (Mumbai–Goa), Kannad plain, Malabar coast (known for backwaters / kayals). Rivers here are short and fast, so they form estuaries, not deltas (Narmada and Tapi also form estuaries).
• Eastern coast (along the Bay of Bengal): wide and level. Northern part = Northern Circars, southern part = Coromandel coast. Big rivers — Mahanadi, Godavari, Krishna, Kaveri — form deltas. Chilika Lake (Odisha) is India's largest saltwater lake.

6. The Islands

Group	Sea	Origin and facts
Lakshadweep	Arabian Sea	Coral islands; capital Kavaratti; Minicoy is separated from Maldives by the Eight Degree Channel
Andaman and Nicobar	Bay of Bengal	Raised parts of a submarine mountain chain; Barren Island is India's only active volcano; the Ten Degree Channel separates Andaman from Nicobar

Worked examples

Example 1 — Turning a fact into a time question
Q: Place A is at 70°E and place B at 85°E. When it is 6:00 a.m. by the sun at B, what is the sun time at A?
Difference = 15°. Time = 15 × 4 = 60 minutes. A is west of B, so its sun time is behind: 5:00 a.m.
Rule: east = ahead, west = behind.

Example 2 — Odd one out with the Tropic of Cancer
Q: The Tropic of Cancer does NOT pass through: (a) Jharkhand (b) Tripura (c) Odisha (d) Mizoram
Recall the 8 states. Odisha lies entirely south of 23°30′N. Answer: (c) Odisha.

Example 3 — Matching relief belts
Q: Match: (1) Bhabar (2) Terai (3) Khadar (4) Bhangar with (p) new floodplain alluvium (q) pebbles where streams vanish (r) old alluvium with kankar (s) marshy belt where streams reappear.
Answer: 1-q, 2-s, 3-p, 4-r. Think of the journey downhill: stones first, then swamp, then the two kinds of alluvium.

Example 4 — Statement-based question
Statement I: The Eastern Ghats are continuous. Statement II: The Deccan Plateau slopes towards the east.
Statement I is false (rivers cut through the Eastern Ghats). Statement II is true (that is why Godavari, Krishna and Kaveri flow east). Only II is correct.

Real-world connection

• Border guarding follows geography: the BSF guards the Pakistan and Bangladesh borders, the ITBP the China border, the SSB the Nepal and Bhutan borders, and the Assam Rifles the Myanmar border. Knowing India's neighbours is part of basic police awareness.
• Disasters follow landforms too: young Himalayas mean earthquakes and landslides; Khadar floodplains mean yearly floods; flat east-coast deltas face cyclones from the Bay of Bengal.
• Time: the sun rises in Arunachal Pradesh about two hours before it rises in Kutch, yet clocks show the same IST.

How it is asked in the exam

You get about 54 seconds per question. Firm facts let you answer these in 15–30 seconds.

Formats seen in this kind of paper:

• Direct recall — "The Standard Meridian of India passes through which city?"
• Odd one out — states on the Tropic of Cancer, ranges of the Himalayas, coastal plains of the east.
• Match the following — divisions with features, peaks with ranges, channels with island groups.
• Statement-based — "Which of the following statements is/are correct?"
• Simple calculation — longitude-to-time conversion.

Difficulty ladder:

• Easy: "Which is the southernmost point of India?" → Indira Point.
• Medium: "The Ten Degree Channel separates which islands?" → Andaman from Nicobar.
• Hard: "Which pair is incorrectly matched? Doda Betta – Nilgiris; Guru Shikhar – Aravallis; Anai Mudi – Eastern Ghats; Kangchenjunga – Sikkim" → Anai Mudi belongs to the Western Ghats.

తెలుగు సారాంశం (Telugu summary)

భారతదేశం పూర్తిగా ఉత్తరార్ధగోళంలో మరియు తూర్పు అర్ధగోళంలో ఉంది. ప్రధాన భూభాగం 8°4′ ఉత్తర అక్షాంశం నుండి 37°6′ ఉత్తర అక్షాంశం వరకు, 68°7′ తూర్పు రేఖాంశం నుండి 97°25′ తూర్పు రేఖాంశం వరకు విస్తరించి ఉంది.
దేశ విస్తీర్ణం సుమారు 32.8 లక్షల చదరపు కిలోమీటర్లు; ఇది ప్రపంచ భూభాగంలో దాదాపు 2.4 శాతం, విస్తీర్ణంలో భారత్‌ది 7వ స్థానం.
కర్కాటక రేఖ (23°30′ ఉత్తరం) దేశాన్ని దాదాపు రెండు సమాన భాగాలుగా విభజిస్తుంది; ఇది 8 రాష్ట్రాల గుండా వెళుతుంది.
82°30′ తూర్పు రేఖాంశం భారత ప్రామాణిక కాలానికి ఆధారం; IST గ్రీన్‌విచ్ కాలం కంటే 5 గంటల 30 నిమిషాలు ముందు ఉంటుంది. ఒక డిగ్రీ రేఖాంశం = 4 నిమిషాలు.
దక్షిణపు చివరి బిందువు ఇందిరా పాయింట్; ప్రధాన భూభాగపు దక్షిణ కొన కన్యాకుమారి. భారత్‌కు 7 దేశాలతో భూ సరిహద్దు ఉంది, బంగ్లాదేశ్‌తో పొడవైన సరిహద్దు.
ఆరు భౌగోళిక విభాగాలు: హిమాలయాలు, ఉత్తర మైదానాలు, ద్వీపకల్ప పీఠభూమి, భారత ఎడారి, తీర మైదానాలు, దీవులు.
హిమాలయాలు యువ ముడత పర్వతాలు; హిమాద్రి, హిమాచల్, శివాలిక్ అనే మూడు సమాంతర శ్రేణులు ఉన్నాయి.
ఉత్తర మైదానాలు నదులు తెచ్చిన ఒండ్రు మట్టితో ఏర్పడ్డాయి: భాబర్, టెరాయ్, భాంగర్ (పాత ఒండ్రు), ఖాదర్ (కొత్త ఒండ్రు).
ద్వీపకల్ప పీఠభూమి అత్యంత పురాతన భూభాగం; పశ్చిమ కనుమలు ఎత్తుగా, అవిచ్ఛిన్నంగా ఉంటాయి, తూర్పు కనుమలు తక్కువ ఎత్తులో, అక్కడక్కడ తెగిపోయి ఉంటాయి.
పశ్చిమ తీరం ఇరుకైనది, అక్కడి నదులు నదీముఖాలను ఏర్పరుస్తాయి; తూర్పు తీరం వెడల్పైనది, అక్కడ డెల్టాలు ఉంటాయి. లక్షద్వీప్ పగడపు దీవులు, బారెన్ ద్వీపం క్రియాశీల అగ్నిపర్వతం.

Key terms (English — తెలుగు):

• Latitude — అక్షాంశం
• Longitude — రేఖాంశం
• Tropic of Cancer — కర్కాటక రేఖ
• Standard Meridian — ప్రామాణిక రేఖాంశం
• Physiography — భౌతిక స్వరూపం
• Fold mountains — ముడత పర్వతాలు
• Plateau — పీఠభూమి
• Peninsula — ద్వీపకల్పం
• Alluvium — ఒండ్రు మట్టి
• Coastal plain — తీర మైదానం
• Estuary — నదీముఖం
• Strait — జలసంధి
• Coral island — పగడపు దీవి
• Sand dune — ఇసుక దిబ్బ