UPSC NDA & NA Geography Syllabus

What is the structure of the atmosphere from the surface upward (lowest four layers)?

Troposphere, Stratosphere, Mesosphere, and Thermosphere (followed by the Exosphere).

In which atmospheric layer does weather occur, and which layer contains the ozone layer?

Weather occurs in the Troposphere (lowest layer); the ozone layer lies in the Stratosphere.

What is the normal lapse rate of temperature in the troposphere?

Temperature decreases at about 6.4°C per 1,000 metres (roughly 1°C per 165 m) of ascent - the normal lapse rate.

What is an inversion of temperature?

A condition in which temperature increases with height instead of decreasing, common on calm, clear nights in valleys; it traps cold air and pollutants near the surface.

Name the three forms of precipitation based on the mechanism of uplift.

Convectional rainfall, Orographic (relief) rainfall, and Cyclonic (frontal) rainfall.

What are the major permanent planetary wind belts?

Trade winds (blowing toward the equator), Westerlies (in mid-latitudes), and Polar easterlies (near the poles).

Define relative humidity.

The ratio (expressed as a percentage) of the actual amount of water vapour present in the air to the maximum it can hold at that temperature.

What is the Coriolis force and its effect on winds?

An apparent deflecting force due to Earth's rotation that deflects winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

What proportion of Earth's surface is covered by water, and what share of that is in the oceans?

About 71% of the surface is water; roughly 97% of all water is held in the oceans (saltwater).

Name the world's oceans in order of size from largest to smallest.

Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Ocean.

What causes ocean tides and how often do high tides usually occur?

Tides are caused mainly by the gravitational pull of the Moon (and partly the Sun) on ocean water; most coasts experience two high tides and two low tides in about 24 hours.

Differentiate spring tides and neap tides.

Spring tides are the highest tides, occurring at new and full moon when Sun, Moon and Earth align; neap tides are the lowest, occurring at the first and third quarter when Sun and Moon are at right angles.

What are ocean currents, and name one warm and one cold current.

Ocean currents are continuous directed movements of seawater. Warm: Gulf Stream (Atlantic); Cold: Labrador Current / Humboldt (Peru) Current.

What is the difference between the continental shelf and the continental slope?

The continental shelf is the shallow, gently sloping submerged margin of a continent (rich in fisheries); the continental slope is the steeper descent from the shelf edge to the deep ocean floor.

What is salinity, and what is the average salinity of ocean water?

Salinity is the total dissolved salt content of seawater, expressed in parts per thousand (ppt); the ocean average is about 35 ppt.

List the broad bases of Koppen's climatic classification scheme.

Koppen's scheme is based on temperature and precipitation, giving five major groups: A (Tropical), B (Dry), C (Warm temperate), D (Cold/Snow), and E (Polar).

Describe the key features of the Equatorial (tropical rainforest) climate.

Hot and wet throughout the year, uniform high temperatures (~27°C), heavy convectional rainfall (>200 cm), high humidity, and dense evergreen rainforest (e.g., Amazon, Congo).

What characterises the Mediterranean type of climate?

Hot, dry summers and mild, wet winters; rainfall concentrated in winter from westerlies; found on west coasts in 30°-45° latitudes (e.g., Mediterranean basin, California).

What are the defining features of the Monsoon type of climate?

Seasonal reversal of winds, hot rainy summers and dry cool winters, rainfall highly seasonal; characteristic of South and Southeast Asia including India.

Describe the Tundra (polar) climate.

Extremely cold, long severe winters, very short cool summers, low precipitation (mostly snow), permanently frozen subsoil (permafrost), and sparse mosses and lichens vegetation.

What is the natural vegetation and typical wildlife of the Tropical Grassland (Savanna) region?

Tall grasses with scattered trees; supports large grazing herbivores (zebra, giraffe, antelope) and predators (lion); the classic example is the African Savanna.

Name the temperate grasslands of the world by their regional names.

Prairies (N. America), Pampas (S. America), Steppes (Eurasia), Veld (S. Africa), Downs (Australia), and Canterbury (New Zealand).

What is the Taiga (Coniferous/Boreal forest) natural region known for?

A belt of cold-climate softwood coniferous forests in the high northern latitudes of Eurasia and North America, the world's chief source of softwood timber and paper pulp.

What is the latitudinal and longitudinal extent of India?

India lies roughly between 8°4'N and 37°6'N latitude and 68°7'E and 97°25'E longitude.

Which is the standard meridian of India and why was it chosen?

82°30'E longitude (passing near Mirzapur, U.P.) is the Standard Meridian; Indian Standard Time is set 5 hours 30 minutes ahead of GMT based on it.

Name the major physiographic divisions of India.

The Northern (Himalayan) Mountains, the Northern (Indo-Gangetic) Plains, the Peninsular Plateau, the Coastal Plains, and the Islands.

What is the difference between black soil and alluvial soil in India?

Black (regur) soil is clayey, moisture-retentive, formed from Deccan lava and ideal for cotton; alluvial soil is deposited by rivers, very fertile, and covers the northern plains supporting most crops.

Which Indian rivers form deltas and which form estuaries on their way to the sea?

East-flowing rivers (Ganga, Godavari, Krishna, Kaveri) form deltas in the Bay of Bengal; west-flowing rivers Narmada and Tapi form estuaries in the Arabian Sea.

What is the difference between Kharif and Rabi crops in India?

Kharif crops are sown with the southwest monsoon (June-July) and harvested in autumn (e.g., rice, maize, cotton); Rabi crops are sown in winter (Oct-Dec) and harvested in spring (e.g., wheat, gram, mustard).

Which is the largest iron and steel producing region of India, and which mineral belt supplies it?

The Chhota Nagpur Plateau (Jharkhand-Odisha-West Bengal) belt is the chief iron and steel region, drawing on the Damodar Valley coalfields and rich iron-ore deposits.

What are the four major modes of transport in India and which carries the bulk of freight and passengers?

Roadways, Railways, Waterways (inland and shipping), and Airways. Indian Railways and roadways together carry the bulk of passenger and freight traffic, with roads handling the largest share.