UPSC NDA Geography Syllabus

In which atmospheric layer does weather occur, and in which is the ozone layer found?

Weather occurs in the Troposphere; the ozone layer is in the Stratosphere.

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

About 6.5 degrees C decrease per 1,000 metres (or 1 degree C per 165 metres) of altitude.

Define 'isobars' and 'isotherms'.

Isobars are lines joining places of equal atmospheric pressure; isotherms are lines joining places of equal temperature.

What are the Trade Winds and from which direction do they blow?

Permanent winds blowing from subtropical high-pressure belts toward the equatorial low; NE in the Northern Hemisphere and SE in the Southern Hemisphere.

What is the Coriolis effect?

The deflection of moving air/water due to Earth's rotation, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Differentiate between weather and climate.

Weather is the short-term, day-to-day state of the atmosphere at a place; climate is the average weather over a long period (about 30+ years).

What causes the Indian monsoon (basic mechanism)?

Seasonal reversal of winds due to differential heating of land and sea; the SW monsoon (June to September) brings most of India's rainfall.

Name the two branches of the South-West Monsoon in India.

The Arabian Sea branch and the Bay of Bengal branch.

What are the three main types of rainfall?

Convectional (heating), Orographic/relief (mountain barrier), and Cyclonic/frontal (meeting of air masses).

What is the largest ocean on Earth and the deepest known point?

The Pacific Ocean is the largest; the Mariana Trench (Challenger Deep) is the deepest point, about 11,000 m deep.

Define 'ocean currents' and name a major warm current.

Large-scale movements of ocean water driven by wind, temperature, and salinity differences. Example warm current: the Gulf Stream (North Atlantic).

What are tides and what causes them?

The periodic rise and fall of sea level caused mainly by the gravitational pull of the Moon (and Sun) on the oceans.

Differentiate between spring tides and neap tides.

Spring tides are the highest tides (Sun, Moon, Earth aligned at new/full moon); neap tides are the lowest (Sun and Moon at right angles, first/third quarter).

What is salinity of ocean water and its average value?

Salinity is the total dissolved salt content; average ocean salinity is about 35 parts per thousand (35 g per litre).

Which sea has the highest salinity, and which is a famous very saline lake?

The Dead Sea (a salt lake) is famous for extremely high salinity; among open seas the Red Sea is highly saline.

Name the largest continent and the smallest continent by area.

Largest: Asia; Smallest: Australia (Oceania as a continent).

What is the longest river in the world and the largest by discharge?

Longest: the Nile (by traditional measure); Largest by discharge/volume: the Amazon.

Name the highest mountain peak in the world and its height.

Mount Everest (Sagarmatha/Chomolungma) at about 8,849 metres.

What is the Tropic of Cancer's latitude, and which Indian states does it pass through (any two)?

23.5 degrees N. It passes through states such as Gujarat, Rajasthan, Madhya Pradesh, Jharkhand, West Bengal, Tripura, Mizoram (any two).

What are India's latitudinal and longitudinal extents?

Latitude about 8 degrees 4 minutes N to 37 degrees 6 minutes N; longitude about 68 degrees 7 minutes E to 97 degrees 25 minutes E.

Name the northernmost mountain range of the Himalayas and its highest Indian peak.

The Greater Himalayas (Himadri); its highest peak in India is Kanchenjunga (about 8,586 m).

Which is the longest river in India and where does it originate?

The Ganga (Ganges); it originates from the Gangotri glacier in the Himalayas.

Name the major Peninsular rivers that flow into the Arabian Sea.

The Narmada and Tapi (Tapti), which flow westward through rift valleys into the Arabian Sea.

What is the Deccan Plateau primarily composed of, and how was it formed?

Mainly basalt (igneous rock) forming the Deccan Traps, created by massive volcanic lava flows.

Differentiate between the Eastern Ghats and Western Ghats.

Western Ghats are continuous, higher, and parallel to the west coast; Eastern Ghats are discontinuous, lower, and dissected by rivers along the east coast.

What is black soil (regur) and which crop is it ideal for?

Clayey, moisture-retentive volcanic soil of the Deccan, rich in iron and lime; ideal for cotton cultivation.

What is alluvial soil and where is it predominantly found in India?

Fertile soil deposited by rivers; found mainly in the Northern Plains (Indo-Gangetic plain) and coastal deltas.

Name the three types of natural vegetation/forests based on rainfall in India.

Tropical evergreen (high rainfall), tropical deciduous/monsoon (moderate rainfall), and thorn/desert vegetation (low rainfall).

What is the Greenhouse Effect?

The trapping of long-wave (infrared) radiation by atmospheric gases (CO2, water vapour, methane), which warms the Earth's surface.

Differentiate between renewable and non-renewable resources with examples.

Renewable can be replenished naturally (solar, wind, water, forests); non-renewable are finite and exhaustible (coal, petroleum, natural gas, minerals).

What is the equinox and when do the two equinoxes occur?

The equinox is when day and night are of equal length worldwide; it occurs around 21 March (spring/vernal) and 23 September (autumnal).