World Geography — Continents, Oceans, Straits, Deserts, Mountains, Rivers

World Geography questions appear in most PSC exams (2-4 questions). Focus on superlatives (longest, highest, largest), important straits, and major physical features.

Continents

Continent	Area (million sq km)	Key Fact
Asia	44.58	Largest continent; most populous
Africa	30.37	Second largest; most countries (54)
North America	24.71	Third largest
South America	17.84	Amazon River, Andes
Antarctica	14.20	Coldest, driest, windiest continent; no permanent population
Europe	10.18	Second smallest; highest GDP per capita
Australia/Oceania	8.53	Smallest continent

Mnemonic (by size): “All Asians Need Some Antarctic European Air” — Asia, Africa, North America, South America, Antarctica, Europe, Australia.

Oceans

Ocean	Area (million sq km)	Key Fact
Pacific	165.25	Largest and deepest; Mariana Trench (10,994 m)
Atlantic	106.46	Second largest; S-shaped; busiest for trade
Indian	70.56	Third largest; named after a country
Southern (Antarctic)	21.96	Recognised officially in 2000 by IHO
Arctic	14.06	Smallest and shallowest

Important Straits

Strait	Separates
Strait of Malacca	Malay Peninsula and Sumatra (Indian-Pacific Ocean link)
Strait of Hormuz	Iran and Oman (Persian Gulf to Arabian Sea — oil route)
Strait of Gibraltar	Spain and Morocco (Atlantic to Mediterranean)
Bab-el-Mandeb	Yemen and Djibouti (Red Sea to Gulf of Aden)
Palk Strait	India (Tamil Nadu) and Sri Lanka
Strait of Dover	England and France (English Channel)
Bering Strait	Alaska (USA) and Russia (Pacific to Arctic)
Strait of Magellan	South America mainland and Tierra del Fuego
Bosphorus	European Turkey and Asian Turkey (Black Sea to Sea of Marmara)
Dardanelles	European Turkey and Asian Turkey (Sea of Marmara to Aegean)
Taiwan Strait	China and Taiwan
Mozambique Channel	Mozambique and Madagascar
Sunda Strait	Java and Sumatra
Cook Strait	North Island and South Island (New Zealand)

Major Deserts

Desert	Location	Type	Key Fact
Sahara	North Africa	Hot	Largest hot desert (9.2 million sq km)
Antarctic	Antarctica	Cold	Largest desert overall (14.2 million sq km)
Arabian	West Asia	Hot	Second largest hot desert
Gobi	Mongolia/China	Cold	Fifth largest
Kalahari	Southern Africa	Hot	Botswana, Namibia, South Africa
Thar	India/Pakistan	Hot	Also called Great Indian Desert
Atacama	Chile	Cold (coastal)	Driest place on earth
Patagonian	Argentina	Cold	Largest desert in South America

Major Mountain Ranges

Mountain Range	Location	Highest Peak
Himalayas	Asia	Mt. Everest (8,849 m) — highest in the world
Karakoram	Asia	K2/Godwin-Austen (8,611 m) — second highest
Andes	South America	Aconcagua (6,961 m) — highest outside Asia
Rocky Mountains	North America	Mt. Elbert (4,401 m)
Alps	Europe	Mont Blanc (4,808 m)
Ural Mountains	Russia	Boundary between Europe and Asia
Atlas Mountains	North Africa	Morocco, Algeria, Tunisia
Great Dividing Range	Australia	Longest range in Australia
Appalachian	Eastern North America	Oldest mountain range in N. America

Highest Peaks by Continent

Continent	Peak	Height
Asia	Mt. Everest	8,849 m
South America	Aconcagua	6,961 m
North America	Denali (Mt. McKinley)	6,190 m
Africa	Mt. Kilimanjaro	5,895 m
Europe	Mt. Elbrus	5,642 m
Antarctica	Vinson Massif	4,892 m
Australia/Oceania	Puncak Jaya	4,884 m

Major Rivers of the World

River	Length (km)	Continent	Key Fact
Nile	6,650	Africa	Longest river in the world
Amazon	6,400	South America	Largest by discharge volume
Yangtze	6,300	Asia	Longest in Asia; longest in China
Mississippi-Missouri	6,275	North America	Longest in N. America
Yenisei	5,539	Asia	Flows into Arctic Ocean
Yellow River (Huang He)	5,464	Asia	”China’s Sorrow” (floods)
Ob-Irtysh	5,410	Asia	Western Siberia
Congo	4,700	Africa	Deepest river in the world
Danube	2,860	Europe	Flows through most countries (10)
Volga	3,530	Europe	Longest in Europe
Rhine	1,230	Europe	Major trade waterway
Murray-Darling	3,672	Australia	Longest in Australia

World Superlatives — Quick Table

Superlative	Answer
Largest country (area)	Russia
Smallest country	Vatican City
Most populous country	India (surpassed China in 2023)
Largest island	Greenland
Largest lake	Caspian Sea (salt)
Largest freshwater lake	Lake Superior
Deepest lake	Lake Baikal (Russia, 1,642 m)
Highest lake	Ojos del Salado crater lake (Chile, 6,390 m)
Largest plateau	Tibetan Plateau (“Roof of the World”)
Deepest ocean point	Mariana Trench (Challenger Deep, 10,994 m) — Pacific Ocean
Largest ocean	Pacific
Saltiest water body	Dead Sea (actually a lake, not a sea)
Longest coral reef	Great Barrier Reef (Australia)
Largest delta	Sundarbans (Ganges-Brahmaputra delta)
Driest place	Atacama Desert (Chile)
Wettest place	Mawsynram (Meghalaya, India)
Hottest place	Death Valley, California (56.7 degrees C recorded)
Coldest place	Vostok Station, Antarctica (-89.2 degrees C recorded)
Highest waterfall	Angel Falls (Venezuela, 979 m)
Largest rainforest	Amazon Rainforest
Longest wall	Great Wall of China

Important Geographic Lines

Line	Significance
Equator (0 degrees)	Divides Northern and Southern hemispheres
Tropic of Cancer (23.5 degrees N)	Passes through India (8 states: Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, WB, Tripura, Mizoram)
Tropic of Capricorn (23.5 degrees S)	Southern limit of sun’s overhead position
Arctic Circle (66.5 degrees N)	6 months day/night at poles begins here
Antarctic Circle (66.5 degrees S)	Southern counterpart
International Date Line	180 degrees longitude; crosses the Pacific Ocean
Prime Meridian (0 degrees)	Passes through Greenwich, London
Durand Line	India (now Pakistan) and Afghanistan border
McMahon Line	India and China (Tibet) border
Radcliffe Line	India and Pakistan border (1947 partition)

Mnemonic for Tropic of Cancer states (west to east): “GReat Men Can Just Win Two Medals” — Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram.

Focus on superlatives, straits, and boundary lines — these are the most frequently repeated question types.