Indian and World Geography Notes for APPSC, DSC & AP Police

Geography is one of the few subjects where a single revision pass can cover three exams at once. The APPSC general studies papers, the AP DSC general knowledge and content sections, and the AP Police Constable and SI papers all ask the same kind of question: where is a feature, how long is it, which state does it cross, why does it behave the way it does. The questions are rarely deep, but they punish people who mix up two lookalike facts, such as the length of the Ganga and the length of the Indus, or the date the monsoon reaches Kerala and the date it covers the whole country.

These notes are built in two halves. The first half covers India in the order most syllabi follow: location, structure and physiography, drainage, climate and the monsoon, soils, natural vegetation, agriculture, minerals and population. The second half covers world geography essentials: continents, oceans, mountains, rivers, deserts, latitudes, longitudes and time zones. Andhra Pradesh is deliberately not repeated here. For rivers, districts, ports, irrigation, crops and minerals of the state, use the dedicated posts linked in each section and in the related reading list.

How the facts were checked: structural and descriptive material follows the current NCERT geography textbooks (the 2026-27 reprints for Class 10 and Class 11, and the Class 12 India: People and Economy book). Numbers that change with time are dated and attributed. These include the monsoon of 2026 from the India Meteorological Department (IMD), crop output from the Ministry of Agriculture's third advance estimates for 2025-26, mineral value from the Indian Bureau of Mines, and forest cover from the India State of Forest Report 2023. Where a figure could not be confirmed in a primary source, the text says so.

1. Location, size and frontiers

The mainland of India stretches from Kashmir in the north to Kanniyakumari in the south, and from Arunachal Pradesh in the east to Gujarat in the west. The mainland lies between roughly 8°4' N and 37°6' N latitude and between 68°7' E and 97°25' E longitude. Counting the Andaman and Nicobar group, the southernmost point is Indira Point in Great Nicobar at about 6°45' N, which is the figure NCERT gives for the southern limit of the country. Because the latitudinal and longitudinal spreads are both close to 30 degrees, students often assume the north-south and east-west distances are equal. They are not. NCERT gives the north-south extent as 3,214 km and the east-west extent as 2,933 km, because the distance between meridians narrows towards the poles while the distance between parallels stays constant.

India's area is about 3.28 million sq km, which is 2.4 per cent of the world's land surface and makes it the seventh largest country. Its territorial waters extend 12 nautical miles (about 21.9 km) from the coast. The standard meridian is 82°30' E, chosen because standard meridians are normally multiples of 7°30'. Indian Standard Time is ahead of Greenwich Mean Time by 5 hours 30 minutes. Because the country spans almost 30 degrees of longitude, the sun rises about two hours earlier in the north-east than in western Rajasthan, yet a single clock is used throughout.

The Ministry of Home Affairs annual report for 2023-24 gives the land border as 15,106.7 km and the coastline, including island territories, as 7,516.6 km. The border by neighbour is a favourite table.

Border	Length (km, MHA Annual Report 2023-24)
Bangladesh	4,096.7
China	3,488.0
Pakistan	3,323.0
Nepal	1,751.0
Myanmar	1,643.0
Bhutan	699.0
Afghanistan	106.0

Remember the order: Bangladesh is longest, then China, Pakistan, Nepal, Myanmar, Bhutan. Other sources quote slightly different land-border totals, so if a question gives only one option near 15,000 km, choose the one closest to 15,106.7. The Tropic of Cancer (23°30' N) passes through the middle of the country, which is why the south is tropical and the north is subtropical. By the standard atlas list it crosses eight states: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram.

India's relief divides the land into three broad categories. NCERT's Class 10 text gives about 43 per cent as plains, about 30 per cent as mountains and about 27 per cent as plateau. This split matters for agriculture, minerals and settlement, and it is a safe place to start any answer on resources.

2. Structure and the six physiographic divisions

NCERT groups India into three geological divisions. The Peninsular Block is the oldest, built of very ancient gneisses and granites and standing as a rigid block since the Cambrian period. The Himalayas and the other peninsular mountains are young, tectonic and still active, which is why they have faults, folds and thrust planes. The Indo-Ganga-Brahmaputra plain was originally a depression that began filling about 64 million years ago, and the alluvium in it is typically 1,000 to 2,000 m deep.

On the surface, physiography is traditionally divided into six regions. Learn the list in this order, because exam options often shuffle it.

Division	What defines it	Typical exam hook
Northern and North-eastern Mountains	Himalayas and the north-eastern hills	Young fold mountains, fast rivers
Northern Plains	Alluvium of the Indus, Ganga and Brahmaputra	Bhabar, Tarai, Bhangar, Khadar
Peninsular Plateau	Oldest and most stable landmass	Deccan, Central Highlands, north-eastern plateau
Indian Desert	North-west of the Aravalli	Marusthali, Luni, below 150 mm rain
Coastal Plains	Western and eastern strips	Submerged versus emergent coast
Islands	Bay of Bengal and Arabian Sea groups	Andaman and Nicobar, Lakshadweep

Two features are used again and again to explain why landforms differ. The Peninsula consists mostly of relict and residual mountains such as the Aravalli, Nallamala, Javadi, Veliconda, Palkonda and Mahendragiri hills, and its river valleys are shallow with low gradients. The Himalaya is the opposite: youthful, steep and cut by gorges, V-shaped valleys, rapids and waterfalls. If a question asks which is older, the answer is always the Peninsular block and the peninsular drainage.

3. The Himalaya and the Northern Plains

The Himalayas are a series of parallel ranges. In the northern list the main ones are the Great Himalaya (the Himadri, the central axial range), the Lesser Himalaya (Himachal) and the outer Shiwalik. NCERT gives the length of the Great Himalayan range as about 2,500 km from east to west with a width of 160 to 400 km from north to south. The ranges bend: they run north-west to south-east in the north-west, east-west in the Darjiling and Sikkim region, south-west to north-west in Arunachal Pradesh and north-south in Nagaland, Manipur and Mizoram. The Himalaya is not only a physical wall; it is a climatic, drainage and cultural divide, because it blocks cold Central Asian air and traps the monsoon. Kangchenjunga, at 8,586 m on the Sikkim-Nepal border, is the highest peak associated with India and the third highest in the world. Mount Everest, at 8,848.86 m, was most recently measured in a 2020 joint survey by Nepal and China.

The Northern Plains extend roughly 3,200 km east to west with an average width of 150 to 300 km and an elevation mostly between 50 and 150 m. From the Himalayan foot southwards they have four belts, and exam questions often ask for them in order.

Belt	Width and nature	Remember
Bhabar	8 to 10 km, coarse boulders at the break of slope	Streams disappear here
Tarai	10 to 20 km, marshy	Streams re-emerge, dense vegetation and wildlife
Bhangar	Older alluvium	Higher ground, contains kankar nodules
Khadar	Newer alluvium	Fresh silt every flood, more fertile

Haryana and Delhi form the water divide between the Indus and Ganga systems. The Brahmaputra flows north-east to south-west and then takes a nearly 90-degree southward turn at Dhubri before entering Bangladesh. The Sundarbans delta, formed at the mouth of the Ganga and Brahmaputra, is among the largest deltas of the world. The plains grow wheat, rice, sugarcane and jute, and they carry a dense population.

4. The Peninsular Plateau, the desert, the coasts and the islands

The Peninsular Plateau rises from about 150 m above the river plains to 600 to 900 m and forms an irregular triangle. It has three parts. The Deccan Plateau is bordered by the Western Ghats on the west, the Eastern Ghats on the east and the Satpura, Maikal and Mahadeo hills in the north. The Central Highlands lie to the north of the Narmada-Satpura line and are bounded by the Aravalli on the west; their general elevation is 700 to 1,000 m, and the Vindhyan and Kaimur ranges give rise to Yamuna tributaries. The north-eastern plateau (Meghalaya and Karbi Anglong) is a detached extension, separated by a depression filled long ago by river deposits. It includes the Garo, Khasi and Jaintia hills, and it is rich in coal, iron ore, limestone and uranium.

The Western Ghats are higher and more continuous than the Eastern Ghats, with an average elevation of about 1,500 m. Anaimudi (2,695 m) in the Anaimalai hills is the highest peak of the Peninsula, followed by Dodabetta (2,637 m) in the Nilgiris. The two ghats meet in the Nilgiris. The Eastern Ghats are discontinuous low hills cut by the Mahanadi, Godavari, Krishna and Kaveri, and their ranges include the Javadi hills, the Palkonda range, the Nallamala hills and the Mahendragiri hills. Andhra Pradesh lies along the Eastern Ghats and the eastern coast, so use the AP geography notes on rivers, districts and ports for the state-level view.

The Indian Desert lies north-west of the Aravalli. It gets below 150 mm of rain a year and is dotted with longitudinal dunes and barchans, mushroom rocks and oases. Its rivers are mostly ephemeral; the Luni, which flows in the southern part and ends in the Rann of Kachchh, is the notable one. Playa lakes yield salt.

The Coastal Plains differ by origin. The western plain is a submerged coast, narrow in the middle and broader to the north and south, with natural harbours (Kandla, Mumbai, Marmagao, Mangaluru, Kochi), no deltas, and the Malabar kayals or backwaters. The eastern plain is broader and is an emergent coast with well-developed deltas of the Mahanadi, Godavari, Krishna and Kaveri. Its continental shelf extends up to about 500 km into the sea, which makes natural ports fewer and harder to build.

NCERT counts about 572 islands and islets in the Bay of Bengal group, lying between about 6° N and 14° N, divided into Andaman in the north and Nicobar in the south by the Ten Degree Channel. Barren Island, the only active volcano in India, belongs to this group. The Lakshadweep group in the Arabian Sea is built of coral, lies 220 to 440 km off the Kerala coast, has about 36 islands of which 11 are inhabited, and is divided by the Nine Degree Channel. A common trap is to swap the two channels: the Ten Degree Channel belongs to the Bay of Bengal group and the Nine Degree Channel to the Arabian Sea group.

5. Drainage: how rivers are classified and the Himalayan system

A river basin is the whole area drained by a river and its tributaries, and the boundary between two basins is a watershed. India's drainage is classified in three ways. By sea, about 77 per cent of the drainage area flows to the Bay of Bengal (Ganga, Brahmaputra, Mahanadi, Krishna and others) and about 23 per cent to the Arabian Sea (Indus, Narmada, Tapi, Mahi, Periyar). By basin size, there are 14 major basins above 20,000 sq km, 44 medium basins between 2,000 and 20,000 sq km, and many minor ones. By origin, there are Himalayan and Peninsular rivers. Himalayan rivers are perennial because they are fed by both snow and rain, and the Peninsular rivers are largely seasonal.

Drainage patterns are a short, regular question. A dendritic pattern looks like tree branches, as on the northern plain. A radial pattern fans out from a hill, as with the rivers rising on the Amarkantak range. A trellis pattern has main streams parallel and tributaries joining at right angles. A centripetal pattern drains into a lake or depression.

The Himalayan drainage has three systems. The Indus is about 2,880 km long in total and about 1,114 km within India, rising near Bokhar Chu in Tibet; its Punjab tributaries (the Jhelum, Chenab, Ravi, Beas and Satluj) together form the Panjnad, and the Chenab is its largest tributary. The Ganga is 2,525 km long and its basin covers about 8.6 lakh sq km in India. It is called the Bhagirathi at the Gangotri source near Gaumukh, becomes the Ganga at Devprayag where it meets the Alaknanda, and enters the plains at Haridwar. The Yamuna is its longest tributary, joined from the south by the Chambal, Sind, Betwa and Ken, while the Ghaghara, Gandak, Kosi and Mahananda join from the north. The Kosi is the "sorrow of Bihar" because it shifts course, and the Damodar was once the "sorrow of Bengal" before the Damodar Valley Corporation tamed it. The Brahmaputra begins near Mansarovar and is called the Tsangpo in Tibet, the Siang or Dihang on entering Arunachal Pradesh, and the Brahmaputra after it joins the Dibang and Lohit. It is known for floods, shifting channels and bank erosion. The Namami Gange Programme, approved as a flagship programme in June 2014, addresses pollution abatement and rejuvenation of the Ganga.

A memory aid for the Panjnad is "Satluj, Beas, Ravi, Chenab, Jhelum", and a question that asks which of the four is not part of it will usually offer the Indus itself.

6. The Peninsular rivers

Peninsular rivers flow in broad shallow valleys with fixed courses and few meanders, and most flow west to east. Two important exceptions are the Narmada and the Tapi, which run west in rift valleys and end in the Arabian Sea without forming deltas. The following lengths come from the NCERT Class 11 drainage chapter and are the usual exam set.

River	Length (km)	Source	Outfall and note
Godavari	1,465	Nashik district, Maharashtra	Bay of Bengal, largest Peninsular system, Dakshin Ganga
Krishna	1,401	Near Mahabaleshwar	Bay of Bengal, tributaries Koyna, Tungabhadra, Bhima
Mahanadi	851	Near Sihawa, Chhattisgarh	Bay of Bengal through Odisha
Kaveri	800	Brahmagiri hills, Karnataka	Bay of Bengal, flows year-round
Narmada	1,312	Amarkantak plateau	Arabian Sea, 27 km estuary, Dhuandhar falls
Tapi	724	Multai, Betul district	Arabian Sea, 79 per cent of basin in Maharashtra

Notes that distinguish the rivers: the Godavari basin covers about 3.13 lakh sq km, of which 49 per cent lies in Maharashtra, 20 per cent in Madhya Pradesh and Chhattisgarh, and the rest in Andhra Pradesh and the neighbouring states. The Krishna basin is divided 27 per cent Maharashtra, 44 per cent Karnataka and 29 per cent Andhra Pradesh and Telangana. The Kaveri carries water through the year because its upper basin receives the south-west monsoon and its lower basin receives the north-east monsoon. The Narmada flows in a rift valley between the Satpura and the Vindhya, and the Sardar Sarovar project is built on it. The Luni, rising near Pushkar, is the largest river of Rajasthan west of the Aravalli and is ephemeral.

For the Andhra Pradesh viewpoint, such as Polavaram, Srisailam, the Krishna delta and the Godavari delta, read the AP rivers, dams and irrigation projects notes rather than repeating details here.

7. Climate and the monsoon

The climate of India is monsoonal in rhythm. Monsoon means a seasonal reversal in wind direction. Several controls act together: latitude (the Tropic of Cancer splits the country), the Himalaya (a shield against cold northern air and a trap for moist air), land-sea distribution, distance from the sea, altitude and relief. Altitude is the classic example: Agra and Darjiling lie at similar latitude, but their January temperatures differ by about 12 degrees.

The mechanism is easiest to remember in steps. In April and May the north-west plains heat up and develop a low pressure area. The Inter Tropical Convergence Zone (ITCZ), a belt of low pressure where trade winds converge, shifts north to roughly 20° to 25° N in July, which is also called the monsoon trough. The south-east trade winds cross the equator between 40° E and 60° E, and the Coriolis force turns them into the south-west monsoon. The westerly jet stream withdraws from north India, and the easterly jet stream along about 15° N is held responsible for the "burst" of the monsoon. El Nino, a warming of the equatorial Pacific off Peru that returns every three to seven years, is linked with weaker monsoons.

India has four seasons in the meteorologists' scheme: the cold weather season (mid-November to February), the hot weather season (March to May), the south-west monsoon season (June to September) and the retreating monsoon season (October and November). Local storms to know are mango showers (pre-monsoon showers in Kerala and Karnataka that help mangoes ripen), blossom showers (coffee flowers in Kerala), the Nor'westers or Kalbaisakhi of Bengal and Assam, and the Loo, a hot dry wind in the northern plains from Punjab to Bihar. In winter, western disturbances from the Mediterranean bring light rain and snow to the north-west, which benefits the rabi crops. The retreating monsoon brings the "October heat" and gives the Tamil Nadu coast most of its rain through the north-east monsoon.

NCERT gives the normal onset over Kerala as 1 June, with Mumbai and Kolkata reached between 10 and 13 June and the whole subcontinent covered by mid-July. IMD's own season summary for 2026 describes the normal date for covering the entire country as 8 July. This difference is a trap: if the question quotes a textbook, choose the textbook, and if it quotes IMD, choose the IMD date.

The 2026 monsoon is a good example of a dated, official figure. IMD's season summary says the monsoon reached the Andaman Sea on 16 May 2026, set in over Kerala on 4 June (three days after the normal date), covered the whole country on 9 July and began to withdraw from west Rajasthan on 19 September. All-India rainfall from June to September was 759.4 mm, which is 87 per cent of the long period average of 868.6 mm and is classed as deficient (below 90 per cent). By region it was 94 per cent in the North-west, 97 per cent in Central India, 76 per cent in the South Peninsula and 74 per cent in East and North-east India. Source: IMD, Salient Features of the 2026 Southwest Monsoon Season, issued 30 September 2026.

Rainfall distribution in NCERT terms: the national average is about 125 cm, with more than 200 cm on the west coast, Western Ghats and the north-east, 100 to 200 cm across parts of the east and the Gangetic plain, 50 to 100 cm across the north-west and the Deccan, and below 50 cm in western Rajasthan, Ladakh and the rain-shadow parts of the Peninsula, including parts of Andhra Pradesh. Mawsynram and Cherrapunji in the Khasi Hills receive over 1,000 cm in a year while Jaisalmer rarely gets more than 9 cm.

8. Soils

NCERT's Class 10 chapter classifies soils into alluvial, black, red and yellow, laterite, arid and forest soils. A table keeps the options separate.

Soil	Where	Key traits	Crops
Alluvial	Northern plains, eastern coastal deltas	Most widespread; Bangar (older, kankar) and Khadar (newer); rich in potash, lime and phosphoric acid	Rice, wheat, sugarcane, pulses
Black (regur)	Deccan trap: Maharashtra, Malwa, Madhya Pradesh, Chhattisgarh, Godavari-Krishna valleys	Clayey, holds moisture, cracks in summer, poor in phosphorus	Cotton
Red and yellow	East and south Deccan, Odisha, Chhattisgarh	Develops on crystalline rocks, reddish from iron	Millets, groundnut, pulses
Laterite	Southern states, Western Ghats, Odisha, north-east	Result of leaching in heavy rain, acidic, low in nutrients	Tea, coffee, cashew
Arid	Western Rajasthan	Sandy, saline, kankar layer below	Cultivable with irrigation
Forest	Hills and mountains	Loamy in valleys, acidic in snow areas	Orchards, tea in conserved slopes

Black soil develops on lava (basalt), and the name regur is a regular answer. Red laterite soils in Tamil Nadu, Andhra Pradesh and Kerala suit cashew, which is why cashew is linked with the east coast. Soil erosion is broadly of two types, gully erosion (ravines such as those of the Chambal) and sheet erosion, and conservation measures include contour ploughing, terrace farming, strip cropping and shelter belts.

9. Natural vegetation and forests

NCERT groups Indian forests into five types. Tropical evergreen and semi-evergreen forests need more than 200 cm of rain and a mean annual temperature above 22 degrees; they occur on the western slope of the Western Ghats, the north-eastern hills and the Andaman and Nicobar Islands, and the trees include rosewood, mahogany, ebony and aini. Tropical deciduous forests, also called monsoon forests, are the most widespread and receive 70 to 200 cm of rain; the moist type (100 to 200 cm) has teak, sal, shisham and sandalwood, and the dry type (70 to 100 cm) covers the plateau and the plains of Uttar Pradesh and Bihar. Tropical thorn forests occur below 50 cm of rain and include babool, ber, khair and neem. Montane forests change with altitude, from deciduous at the foothills through wet temperate (1,000 to 2,000 m) with oak and chestnut, to pine, deodar and blue pine, then alpine pastures and tundra; the southern montane forests of the Nilgiris, Anaimalai and Palani are called sholas. Littoral and swamp forests include the mangroves.

The most recent India State of Forest Report (ISFR 2023, published by the Forest Survey of India) gives the latest assessment I could open. Total forest and tree cover is 8,27,356.95 sq km, which is 25.17 per cent of the geographical area. Of this, forest cover is 7,15,342.61 sq km (21.76 per cent) and tree cover is 1,12,014.34 sq km (3.41 per cent). Mangrove cover is 4,991.68 sq km, about 0.15 per cent of the country, and ISFR 2023 notes that Andhra Pradesh recorded one of the notable increases in mangroves compared with 2021. Madhya Pradesh has the largest forest cover by area, followed by Arunachal Pradesh and Chhattisgarh. India's long-standing forest policy target is one-third of the land under forest and tree cover, which is a different yardstick from the ISFR forest cover percentage, so read the question carefully. Andhra Pradesh's forests and parks are covered in the AP forests, wildlife and national parks post.

10. Agriculture and land use

NCERT describes three cropping seasons. Rabi crops (wheat, barley, peas, gram, mustard) are sown in winter from October to December and harvested in summer. Kharif crops (rice, maize, jowar, bajra, cotton, jute, groundnut, soybean) are sown with the onset of the monsoon and harvested in September and October. Zaid crops (watermelon, muskmelon, cucumber, vegetables, fodder) are grown in the short summer season in between. India is the second largest producer of rice, wheat, sugarcane and several fruits, and the largest producer of pulses and milk; for any "rank" question, check whether the textbook edition in your reading is older than the official figures.

For production, the cleanest official source is the Ministry of Agriculture and Farmers Welfare. Its Third Advance Estimates for 2025-26, released in May 2026, put total foodgrain production at 376.56 million tonnes, compared with 357.73 million tonnes in 2024-25. Rice was 154.02 million tonnes, wheat 120.65 million tonnes, maize 55.09 million tonnes, total oilseeds 43.05 million tonnes and sugarcane 500.06 million tonnes. Advance estimates are revised later, so write "2025-26, third advance estimates" whenever you quote them. The deficient 2026 monsoon described above bears on kharif 2026-27 output, but the official estimates for that year have not been released at the time of writing.

Land use is a table that the NCERT Class 10 book builds from Ministry of Agriculture data: reporting is available for about 93 per cent of the total geographical area, and the net sown area including current fallow is about 54 per cent of the reporting area. The share varies by state, from over 80 per cent in Punjab and Haryana to under 10 per cent in Arunachal Pradesh, Mizoram, Manipur and the Andaman and Nicobar Islands. For Andhra Pradesh cropping patterns, canals and tanks use the AP agriculture, irrigation and crops notes.

11. Minerals and energy

Minerals are unevenly distributed. The Peninsular rocks hold most of the coal, metallic minerals and mica; the sedimentary rocks on the flanks of the Peninsula, in Gujarat and in Assam hold the petroleum; and the vast alluvial plains of the north have almost no economic minerals. NCERT's mode-of-occurrence list is a standard question: veins and lodes in igneous and metamorphic rocks (copper, zinc, lead, tin), beds in sedimentary rocks (coal, some iron ore, gypsum, potash), residual weathering (bauxite), placer deposits (gold, silver, tin) and ocean water (salt, magnesium, bromine).

The iron ore belts to remember are the Odisha-Jharkhand belt (Badampahar in Mayurbhanj and Kendujhar, Gua and Noamundi in Singhbhum), the Durg-Bastar-Chandrapur belt (the Bailadila range in Bastar, which exports through Visakhapatnam), the Ballari-Chitradurga-Chikkamagaluru-Tumakuru belt in Karnataka (including Kudremukh) and the Maharashtra-Goa belt. NCERT notes that in 2018-19 nearly 97 per cent of iron ore came from Odisha, Chhattisgarh, Karnataka and Jharkhand. Magnetite is the richest ore at up to 70 per cent iron, and hematite (50 to 60 per cent) is the most used.

For production value use the Indian Bureau of Mines, and always state the year. Its Indian Mineral Industry at a Glance 2022-23, issued in May 2025, reports the value of mineral production, covering metallic and non-metallic minerals and excluding fuel and atomic minerals, at Rs 1,20,108 crore in 2022-23, roughly 13 per cent lower than the previous year. Metallic minerals contributed about 90 per cent of the value. Iron ore production was 257 million tonnes, bauxite 23 million tonnes and limestone 406 million tonnes. By state, Odisha led with Rs 50,291 crore, followed by Rajasthan (Rs 21,037 crore), Chhattisgarh (Rs 18,400 crore) and Karnataka (Rs 13,423 crore). Andhra Pradesh's share was Rs 1,326 crore. This is the most recent edition I could open, and a newer edition may exist. For the state's minerals, industries and ports, see the AP minerals, industries, SEZs and ports notes.

12. Population basics

The latest completed census is the 2011 Census. India's population was 1,210,854,977 (about 121 crore), of which 623,724,568 were males and 586,469,294 were females. The sex ratio was 943 females per 1,000 males, the child sex ratio (0 to 6 years) was 919, the density was 382 persons per sq km, the decadal growth rate was 17.7 per cent and literacy was 74.04 per cent (males 82.14 per cent and females 65.46 per cent). Urban residents were about 31.1 per cent. Uttar Pradesh was the most populous state and Sikkim the least; Bihar had the highest density and Arunachal Pradesh the lowest. NCERT's Class 12 book records the density rising from 117 persons per sq km in 1951 to 382 in 2011.

The next census is under way. The Government has announced Census 2027 in two phases: houselisting between April and September 2026 and population enumeration in February 2027 with a reference date of 1 March 2027 (snow-bound areas are counted earlier, with a reference date of 1 October 2026). A Press Information Bureau note of 25 April 2026 describes it as the first digital census and says caste enumeration is included. Its results will not be available before 2027, so any figure in an exam "as per the latest census" still means 2011.

13. World geography: continents and oceans

The seven-continent model is the one used in Indian exams. Areas below are standard reference values for exam use.

Continent	Area (million sq km)	Share of world land	Note
Asia	44.6	29.8 per cent	Largest, most populous
Africa	30.4	20.3 per cent	Second largest
North America	24.2	16.2 per cent
South America	17.8	11.9 per cent
Antarctica	14.2	9.5 per cent	No permanent population
Europe	10.0	6.7 per cent
Oceania (Australia)	8.5	5.7 per cent	Smallest

The ocean covers about 71 per cent of the Earth. The National Oceanic and Atmospheric Administration notes that there is really one global ocean divided into named regions, with the Southern Ocean being the most recently named. The usual areas are Pacific about 168.7 million sq km, Atlantic about 85.1, Indian about 70.6, Southern about 22.0 and Arctic about 15.6. The Pacific is both the largest and the deepest. The deepest point is the Challenger Deep in the Mariana Trench at about 10,935 m.

The Indian Ocean is the only ocean named after a country, and its two arms are the Bay of Bengal and the Arabian Sea. Important narrow waterways for exams are the Strait of Malacca (between the Malay Peninsula and Sumatra), the Strait of Hormuz, the Bab-el-Mandeb, the Suez Canal linking the Mediterranean and the Red Sea, the Panama Canal linking the Atlantic and the Pacific, and the Palk Strait between India and Sri Lanka.

14. World mountains, rivers and deserts

Mountain ranges grouped by continent make a compact table.

Continent	Main ranges	Highest peak (m)
Asia	Himalaya, Karakoram, Hindu Kush, Tien Shan, Urals (part)	Everest, 8,848.86 (2020 survey)
South America	Andes (longest continental range)	Aconcagua, 6,961
North America	Rockies, Appalachians	Denali, 6,194
Africa	Atlas, Drakensberg	Kilimanjaro, 5,895
Europe	Alps, Pyrenees, Caucasus	Elbrus, 5,642
Antarctica	Transantarctic	Vinson Massif, 4,892
Oceania	Great Dividing Range	Puncak Jaya, 4,884 (Kosciuszko, 2,228, if mainland Australia only)

The usual list of long rivers is the Nile at about 6,650 km, the Amazon at about 6,400 km, the Yangtze at 6,300, the Mississippi-Missouri at 6,275, the Yenisey-Angara and the Yellow River (Huang He). Researchers still debate whether the Nile or the Amazon is longer, depending on where the source and mouth are measured, so a question that says "traditionally" expects the Nile, and one that asks for the largest by volume expects the Amazon.

The largest deserts by area are the Antarctic Desert (14.2 million sq km) and the Arctic Desert (about 13.9 million), followed by the Sahara (about 9.2 million sq km), which is the largest hot desert, then the Arabian, Gobi, Kalahari and Patagonian. A desert is defined by low rainfall, so the polar ice deserts qualify. Know the cold desert, the Gobi, and the Indian Thar. Landlocked and island facts that recur: Greenland is the largest island, Russia the largest country by area, and the Vatican City the smallest.

15. Latitudes, longitudes and time zones

Latitudes are parallels measured north or south of the Equator (0°). The ones that matter are the Tropic of Cancer (23°30' N), the Tropic of Capricorn (23°30' S), the Arctic Circle (66°30' N) and the Antarctic Circle (66°30' S). Longitudes are meridians measured east or west of the Prime Meridian (0°) that passes through Greenwich. A degree of longitude corresponds to four minutes of time, so 15 degrees equal one hour. NCERT explains that the world is divided into 24 major time zones and that the 180° meridian is where the International Date Line is placed. Crossing it eastward means going back one calendar day, and crossing it westward means going forward one day.

Worked example 1. When it is 12 noon at Greenwich, what is the time at 90° E? The difference is 90 degrees, which is 360 minutes or 6 hours. Time increases to the east, so the local time is 6 p.m. NCERT uses the same example with Thimphu and with New Orleans at 90° W, where the time is 6 a.m.

Worked example 2. India's standard meridian is 82°30' E, which gives 82.5 × 4 = 330 minutes, which is 5 hours 30 minutes ahead of Greenwich. For a quick comparison, Dibrugarh at about 95° E is 12.5 degrees east of the standard meridian, so its sun-time is about 50 minutes ahead of IST, while Jaisalmer at about 70° E is about 50 minutes behind. That is why the north-east sees sunrise early and the debate about a second time zone for India recurs.

Countries with a very large east-west extent may use several standard meridians. NCERT cites the United States, which has seven time zones. Some countries use a half-hour or 45-minute offset. India is UTC+5:30, and Nepal is UTC+5:45.

16. Common exam traps

• Confusing the Indus (about 2,880 km in total, 1,114 km inside India) with the Ganga (2,525 km). The Ganga is the longest river of India in length inside the country.
• Using Kangchenjunga's height for Everest, or the reverse. Everest is not in India, and Kangchenjunga is not wholly in India either.
• Believing the Western Ghats and the Eastern Ghats meet at the Sahyadri. They meet in the Nilgiris.
• Mixing the Ten Degree Channel (Andaman from Nicobar) with the Nine Degree Channel (which divides the Lakshadweep group).
• Taking the Narmada and Tapi as delta-forming rivers. They flow in rift valleys and form estuaries.
• Saying the monsoon covers India on a fixed date. The NCERT mid-July figure and the IMD 8 July normal are both quoted.
• Quoting a record crop or mineral value without its year. Always write "2025-26 third advance" or "2022-23".
• Treating the Census 2027 announcement as a result. Population figures remain those of 2011 until the next release.

17. How to revise this in seven days

1. Day 1: location, border table, latitudes, longitudes and time. Redo the Greenwich and IST examples without looking.
2. Day 2: physiography and Himalaya, Northern Plains belts, plateau and ghats.
3. Day 3: Himalayan rivers with length, source, tributaries and the exam "sorrow" rivers.
4. Day 4: Peninsular rivers, the table in section 6, and the AP link.
5. Day 5: climate, the monsoon steps and the IMD 2026 numbers.
6. Day 6: soils, forests and agriculture, ending with the ISFR and advance estimate figures.
7. Day 7: minerals, population, then the world: continents, oceans, mountains, deserts. Finish with a timed mock.

Key facts for exams

• India: about 3.28 million sq km, seventh largest, 2.4 per cent of world land, 15,106.7 km land border and 7,516.6 km coastline (MHA Annual Report 2023-24).
• Standard meridian 82°30' E, IST is GMT plus 5 hours 30 minutes, Tropic of Cancer at 23°30' N.
• Great Himalayan range about 2,500 km long; Bhabar 8 to 10 km, Tarai 10 to 20 km; Northern Plains about 3,200 km long.
• Anaimudi, 2,695 m, is the highest peak of the Peninsula; Barren Island is India's only active volcano.
• Godavari 1,465 km, Krishna 1,401 km, Narmada 1,312 km, Mahanadi 851 km, Kaveri 800 km, Tapi 724 km.
• About 77 per cent of drainage goes to the Bay of Bengal and 23 per cent to the Arabian Sea.
• Monsoon 2026 (IMD): 87 per cent of the long period average, onset over Kerala 4 June, withdrawal began 19 September.
• ISFR 2023: forest cover 21.76 per cent, tree cover 3.41 per cent, total 25.17 per cent.
• Third advance estimates 2025-26: foodgrains 376.56 million tonnes.
• IBM 2022-23: value of mineral production Rs 1,20,108 crore, Odisha first.
• Census 2011: 1,210,854,977 people, sex ratio 943, literacy 74.04 per cent, density 382.
• World: Challenger Deep about 10,935 m; Everest 8,848.86 m (2020); Sahara about 9.2 million sq km; 24 time zones; International Date Line near 180°.

10 practice MCQs

1. The standard meridian of India is: a) 68°7' E b) 82°30' E c) 97°25' E d) 75°00' E Answer: b. IST is calculated from it and is 5 hours 30 minutes ahead of Greenwich.

2. Which belt of the Northern Plains is the marshy zone where streams re-emerge? a) Bhabar b) Tarai c) Bhangar d) Khadar Answer: b. Bhabar is where streams disappear into boulder beds, and the Tarai lies to its south.

3. The highest peak of the Peninsular plateau is: a) Dodabetta b) Mahendragiri c) Anaimudi d) Nallamala Answer: c. Anaimudi is 2,695 m; Dodabetta, at 2,637 m, is the second.

4. Which Peninsular river flows west and ends in the Arabian Sea? a) Krishna b) Mahanadi c) Narmada d) Kaveri Answer: c. The Narmada flows in a rift valley and forms an estuary.

5. Approximately what share of India's drainage area is oriented towards the Bay of Bengal? a) 23 per cent b) 50 per cent c) 66 per cent d) 77 per cent Answer: d. The rest goes to the Arabian Sea.

6. The all-India rainfall of the 2026 south-west monsoon season was reported by IMD as: a) 87 per cent of LPA b) 96 per cent of LPA c) 104 per cent of LPA d) 112 per cent of LPA Answer: a. 759.4 mm against a long period average of 868.6 mm, classed as deficient.

7. Black soil is best suited to which crop? a) Tea b) Cotton c) Cashew d) Jute Answer: b. It is also called regur and develops on the Deccan lava.

8. According to ISFR 2023, forest cover as a percentage of India's geographical area is: a) 17.00 b) 21.76 c) 25.17 d) 33.00 Answer: b. The 25.17 per cent figure is forest plus tree cover.

9. When it is 12 noon at Greenwich, the local time at 90° E is: a) 6 a.m. b) 12 noon c) 6 p.m. d) 12 midnight Answer: c. Four minutes per degree gives 6 hours ahead.

10. The largest hot desert in the world is the: a) Gobi b) Thar c) Sahara d) Kalahari Answer: c. The Antarctic and Arctic deserts are larger, but they are cold polar deserts.

Frequently asked questions

Which is the longest river inside India? The Ganga at 2,525 km. The Indus is longer in total but only about 1,114 km of it lies in India, and the Brahmaputra's long Tibetan stretch also lies outside.

Does Andhra Pradesh need a separate geography preparation? Yes. The state's rivers, districts, ports, minerals, crops and forests have their own posts, linked above. This post covers the national layer that all three exams share.

Why do textbooks and IMD give different dates for monsoon coverage? NCERT describes the monsoon as reaching the whole subcontinent by mid-July, while IMD uses 8 July as the normal date for covering the whole country. Use the source named in the question.

Are the latest figures for crops and minerals fixed? No. Advance estimates are revised, and the mineral value quoted here is from the 2022-23 edition. Write the year with every figure.

Will Census 2027 data appear in the next exams? Not soon. Enumeration is scheduled for February 2027, so questions still draw on the 2011 Census.

How much of world geography do the exams ask? Usually a handful of questions: continents, oceans, rivers, mountains, deserts and time. The tables above cover the common set.

Is a map needed for revision? Yes. Draw the Himalayan and Peninsular rivers on a blank outline map once a week, and mark the iron ore belts and the Western and Eastern Ghats.

Related reading

• AP geography notes: rivers, districts and ports
• AP rivers, dams and irrigation projects notes
• AP agriculture, irrigation and crops notes
• AP minerals, industries, SEZs and ports notes
• AP forests, wildlife and national parks
• Indian polity and Constitution notes for APPSC, DSC and AP Police
• Indian economy basics for APPSC, DSC and AP Police
• Telugu version of this post

Practise on pareeksha.in

After one pass through these notes, attempt a timed geography set on pareeksha.in and review every wrong answer against the table it came from. The platform offers 10 Lakh+ MCQs, 100+ Exams and 5,000+ Full-Length Mocks. For any time-sensitive figure, such as monsoon, production or census data, check the latest official release.

Sources and verification

Pages opened for this post:

• NCERT Geography, Class 11, India: Physical Environment (2026-27 reprint), chapters on location, structure and physiography, drainage, climate and natural vegetation (ncert.nic.in).
• NCERT Geography, Class 10, Contemporary India II (2026-27 reprint): resources and development (land use, soils), agriculture, minerals and energy.
• NCERT Geography, Class 11, Practical Work in Geography, chapter on latitude, longitude and time, and the Fundamentals of Physical Geography chapters on oceans, continents and landforms (read for context).
• NCERT Geography, Class 12, India: People and Economy, population chapter (Census 2011 density and growth).
• Ministry of Home Affairs, Annual Report 2023-24, border management chapter (land border and coastline).
• India Meteorological Department, Salient Features of the 2026 Southwest Monsoon Season (30 September 2026).
• Forest Survey of India, India State of Forest Report 2023, Volume I (salient findings and tables) and the FSI report page.
• Ministry of Agriculture and Farmers Welfare, Third Advance Estimates 2025-26 (figures read from a news report of the 27 May 2026 release; the Ministry's own site did not load).
• Indian Bureau of Mines, Indian Mineral Industry at a Glance 2022-23 (May 2025).
• Press Information Bureau, Census 2027 explainer (25 April 2026).
• Wikipedia pages on the 2011 Census of India, Geography of India, continents, oceans, lists of rivers and deserts, the Seven Summits, Mount Everest and time zones (cross-check only, for the Census 2011 final totals and world reference values).
• NOAA National Ocean Service, "How many oceans are there".

Not verified in a primary source and hedged in the text: the exact land-border total (sources differ, MHA 15,106.7 km used); the list of eight states on the Tropic of Cancer (standard atlas list, not opened in a primary source); the Tropic, Arctic Circle and Antarctic Circle latitudes (standard values); world continent, ocean, river and desert figures (cross-checked in reference summaries, not in a national agency table); the Nile versus Amazon length debate; the Census 2011 sex ratio, literacy and urban share (read from a reference summary); the Third Advance Estimates (read from a news report); and any later edition of the Indian Bureau of Mines yearbook or any newer forest report than ISFR 2023.