Geography: UPSC Previous Year Questions (Prelims)

Explanation

Statement 1 is incorrect: Generally the westerlies flow between 30°N and 60°N and 30°S and 60°S latitude respectively, not between 30°N and 60°S latitudes.

Statement 2 is correct: The moist air masses that cause winter rains in the north-western region of India are indeed part of the westerlies. These are often referred to as winter disturbances or western disturbances, which bring moisture from the Mediterranean region, contributing to the winter rainfall in parts of India, especially the north-west.

Explanation

The passage describes a typical daily weather pattern characterized by:

Clear and bright mornings with a sea breeze.

As the Sun climbs high, heat builds up, causing dark clouds to form. Afternoon rain with thunder and lightning. The rain is short-lived, and this pattern repeats daily. This pattern is characteristic of equatorial regions, which experience convectional rainfall due to the intense heating of the Earth’s surface throughout the day. The high humidity and consistent temperatures near the equator lead to daily thunderstorms, often in the afternoon.

Explanation

The Equatorial Counter Current (CEC) is an eastward-flowing current located between the North Equatorial Current (NEC) and the South Equatorial Current (SEC) in the oceans near the equator. It is most prominent in the Pacific and Indian Oceans and helps redistribute heat across the equator, contributing to global climate regulation.

Option (a) is incorrect: While the Earth’s rotation influences large-scale oceanic circulation through the Coriolis force, it does not directly explain the eastward flow of the Equatorial Counter Current. The Coriolis effect is minimal near the equator.

Option (b) is correct: The North Equatorial Current (NEC) and the South Equatorial Current (SEC) flow westward due to trade winds. As these currents converge in the western parts of the oceans, water piles up. Under the influence of gravity, this piled-up water flows eastward, forming the Equatorial Counter Current.

Option (c) is incorrect: While salinity influences vertical water movement, its impact on large-scale horizontal currents like the Equatorial Counter Current is negligible.

Option (d) is incorrect: The Doldrums (regions of calm winds near the equator) do not actively cause the eastward flow. Instead, they create areas of weak wind, which are more relevant for localized weather conditions than large-scale currents. Fig.: Equatorial counter current in Pacific Ocean

Explanation

Tides are the periodic rise and fall of sea levels, driven by various forces acting upon Earth’s water bodies. These forces include:

The Sun’s gravitational pull plays a secondary role in creating tides, as it is much farther away from Earth compared to the Moon. However, its gravitational influence still contributes significantly to spring tides (higher-than-normal tides) when the Sun, Moon, and Earth are aligned (new moon and full moon phases). The Moon’s gravitational force is the primary driver of tides. Due to its proximity to Earth, the Moon exerts a stronger pull on Earth’s oceans, causing the bulge of water that forms high tides. The gravitational pull of the Moon is nearly 2.5 times more effective than that of the Sun in causing tides due to its closer proximity. The Earth-Moon system rotates around a common center of mass, creating a centrifugal force that acts opposite to the Moon’s gravitational pull. This force also contributes to the formation of tides on the side of Earth opposite the Moon, leading to high tides there. It helps explain the formation of high tides on the side of Earth opposite the Moon.

Explanation

Option (a) is incorrect: Saltpetre (Potassium nitrate) is not used in steel production. It is used in the production of fertilizers, rocket propellants, fireworks, and tree stump removal.

Option (b) is incorrect: Rock phosphate is used in the production of fertilizers, not in steel production. It is primarily a source of phosphorus.

Option (c) is correct: Coking coal is crucial for steel production. It is used in the process of converting iron ore into iron and then into steel. India has limited reserves of high-quality coking coal, and more than 60% of the coking coal requirement of the domestic steel industry is met through imports.

Explanation

Teak(Tectona grandis) is a dominant tree species of Tropical moist deciduous forest. Tropical moist deciduous forests are found in the states of Jharkhand, Chhattisgarh, West Odisha, and on the eastern slopes of the Western Ghats. Also known as Monsoon Forests, annual rainfall in these forests is in the range of 100 to 200 cm Characteristics of Tropical Moist Deciduous Forests Rainfall: 1000-2000 mm annually Temperature: 24-32°C Seasonality: Distinct wet and dry seasons, leading to partial shedding of leaves during dry months Soil: Deep, fertile, well-drained alluvial and lateritic soils Main Trees are Teak (Tectona grandis), Sal (Shorea robusta), Sandalwood, Rosewood, Indian Laurel, Mahua, etc.

Explanation

The Godavari is India’s second longest and third-biggest river, after the Ganga. Through a vast network of tributaries, the river eventually drains into the Bay of Bengal. The Godavari is the greatest river in peninsular India in terms of length, catchment area, and flow, and has been nicknamed the Dakshina Ganga, or "Southern Ganga." It originates from Trimbakeshwar in Maharashtra. Options 2 and 3 are correct:

Indravati River is one of the most significant tributaries of the Godavari, originating from the Dandakaranya Plateau in Kalahandi district, Odisha. It flows westward through Chhattisgarh and Maharashtra before joining the Godavari near Bhadrachalam, Telangana. It plays a crucial role in the region’s hydrology by supporting the Indravati Hydroelectric Project, one of India’s largest hydroelectric power projects. Pranahita River is another major tributary of the Godavari formed by the confluence of the Wardha and Wainganga rivers in Maharashtra. It flows southward through Maharashtra and Telangana and eventually merges into the Godavari. Pranahita is considered one of the largest tributaries of Godavari in terms of water volume and significantly contributes to the river’s flow, especially during the monsoon. Other tributaries of Godavari include Manjra, Pravara, Purna, and Kinnerasani. Options 1 and 4 are incorrect:

The Vamsadhara River rises in the Durgakangar Hills of the Eastern Ghats in the Kalahandi district of Odisha. It flows through Odisha and Andhra Pradesh before draining into the Bay of Bengal. The Pennar rises in the Chennakesava hill of the Nandidurga range, in Chikkaballapura district of Karnataka and flows eastward eventually draining into the Bay of Bengal.

Explanation

Option (a) is correct: Living root bridges (Jing Kieng Jri) in Meghalaya are crafted by the Khasi and Jaintia tribes using aerial roots of Ficus elastica (Indian rubber tree). These eco-friend-ly, self-sustaining bridges grow stronger over time, resist floods, and support heavy loads. The Umshiang Double-Decker Root Bridge is a famous example of this sustainable engineering. Living root bridges require high humidity, evergreen forests, and tree species like Ficus elastica (Indian rubber tree) which thrive in tropical climates.

Explanation

Tropical Wet Evergreen Forests are characterized by high rainfall (typically over 2500 mm annually), high humidity(over 77 perecent) and warm temperatures(over 25°C) throughout the year. They are dense, multi-layered forests with a great diversity of plant and animal life. The trees in these forests are evergreen, meaning they do not shed their leaves simultaneously due to the high heat and humidity. The important species of these forests are mahogany, mesua, white cedar, jamun, canes, bamboo, etc.

Option 1 and 3 are correct: In India, tropical wet evergreen forests are found on the eastern and western slopes of the Western Ghats in such states like Tamil Nadu, Karnataka, Kerala and Maharashtra. They are also found in Assam, Arunachal Pradesh, Meghalaya, Nagaland, Tripura, Mizoram, West Bengal and Andaman and Nicobar Islands.

Option 2 is incorrect: Himachal Pradesh comes under the Montane type of forest. The Montane Forests are characterized by the decrease in temperature with increasing altitude that leads to a corresponding change in natural vegetation. As such, there is a succession of natural vegetation belts in the same order as observed from the tropical to the tundra region.

Explanation

The Andaman & Nicobar Islands uniquely house a combination of mangrove, evergreen, and deciduous forests, making them one of India’s most ecologically diverse regions. The Andaman and Nicobar Islands have a tropical rainforest canopy. The Middle Andamans harbours mostly moist deciduous forests. North Andamans is characterised by the wet ever-green type, with plenty of woody climbers. The coastal regions of Andaman and Nicobar Islands have mangrove forests.