Geography: UPSC Previous Year Questions (Prelims)

Explanation

The Onge, a Particularly Vulnerable Tribal Group (PVTG) inhabit Little Andaman Island of Andaman and Nicobar Islands. They are one of the oldest tribes of India, believed to have migrated from Africa around 60,000 years ago.The Onges are hunter-gatherers and rely on forest produce and fishing for survival. Their population is critically low, with fewer than 150 members as per the latest census.

Option (b), (c) and (d) are incorrect:

Dadra and Nagar Haveli is home to tribes like the Warli, Kokna, and Dhodia but not the Onge tribe. The tribes here are primarily engaged in agriculture and forest-based occupations. Daman and Diu, in contrast, has a smaller tribal presence and is better known for its Portuguese colonial heritage blended with Gujarati culture. Tribal communities are less culturally prominent here compared to Dadra and Nagar Haveli or Lakshadweep. Lakshadweep’s population is predominantly Muslim with traditional social groups like the Koyas (landowners), Melacheris (laborers), and Aminidivi (boat builders). Their rich maritime culture revolves around seafaring and fishing, influenced by Islamic traditions. They speak Malayalam and Dhivehi, showcasing a cultural fusion unique to their island environment.

Explanation

Malaysia is not part of the Mekong River basin. The river does not flow through Malaysia at any point. Malaysia’s major rivers include the Rajang River and Kinabatangan River. The Mekong River is one of the longest rivers in Asia (about 4,350 km long). It originates in China’s Tibetan Plateau and flows through six countries: China, Myanmar, Laos, Thailand, Cambodia, and Vietnam before emptying into the South China Sea.

Explanation

Option (d) is correct: Latvia is a Baltic country in Northern Europe, bordered by four countries: Estonia to the north, Russia to the east, Belarus to the southeast, and Lithuania to the south. It also has a western coastline along the Baltic Sea. Latvia does not share a border with Poland. Options (a), (b) and (d) are incorrect:

Latvia shares a border with Russia to the east, specifically in the Pskov and Leningrad regions. Latvia is directly north of Estonia, and both countries share a common border. Lithuania borders Latvia to the south, making this option incorrect.

Explanation

A is matched with 1: The Black Sea is an inland sea in south-eastern Europe. It is bordered by six countries: Bulgaria, Romania, Ukraine, Russia, Georgia, and Turkey. Bulgaria’s eastern coastline lies along the western edge of the Black Sea, providing it with significant maritime access. This strategic position has historically facilitated trade and cultural exchanges between Bulgaria and other Black Sea nations. B is matched with 3: The Red Sea is a seawater inlet of the Indian Ocean. It is situated between northeastern Africa and the Arabian Peninsula. It is bordered by several countries, including Egypt to the northwest, Sudan to the southwest, and Eritrea to the southeast. Djibouti and Saudi Arabia lie to the east, while Yemen is situated to the southeast. The Red Sea is also connected to the Mediterranean Sea through the Suez Canal and to the Arabian Sea via the Bab el-Mandeb Strait. C is matched with 2: The Yellow Sea is a marginal sea of the Western Pacific Ocean. It lies between mainland China and the Korean Peninsula. D is matched with 4: The Caspian Sea is recognized as the world’s largest inland body of water, and is bordered by five countries, namely, Kazakhstan, Russia, Azerbaijan, Iran, and Turkmenistan.

Explanation

Option (d) is correct: Venezuela is situated on the northern coast of South America, bordered by the Caribbean Sea to the north, Colombia to the west, Brazil to the south, and Guyana to the east. Notably, Venezuela does not share a border with Panama; the two countries are separated by Colombia. Options (a), (b) and (c) are incorrect: Panama, a Central American nation, is strategically positioned on the Isthmus of Panama, connecting North and South America. It shares its western border with Costa Rica, while Colombia lies to the east. The Pacific Ocean forms its southern coastline, and the Caribbean Sea borders it to the north. This unique geography has established Panama as a critical conduit for international maritime trade, exemplified by the Panama Canal, which links the Atlantic and Pacific Oceans.

Explanation

Statement 1 is correct: National Thermal Power Corporation (NTPC) has diversified into the hydropower sector as part of its efforts to expand into more environmentally friendly energy sources. It has undertaken projects like the Koldam Hydro Electric Power Project in Himachal Pradesh and other hydropower projects in Uttarakhand and West Bengal. Additionally, NTPC has acquired stakes in hydro-focused companies like THDC India and NEEPCO, further expanding its hydropower portfolio.

Statement 2 is correct: Power Grid Corporation of India (PG-CIL) has diversified into the telecom sector through its subsidiary, Power Grid Teleservices Limited, under the brand name PowerTel. It uses its extensive transmission network for laying optical fiber cables and offers telecom services, including leasing bandwidth to telecom operators.

Explanation

Kolkata-Hajira (Part of former NH6, now mostly NH53) is a major east-west corridor, traversing several states and covering a considerable distance. It is one of the longer na-tional highways in India, approximately in the range of 1900-2000 km, and it is likely the longest of the options. It runs west to east through Gujarat, Maharashtra, Chhattisgarh, Odisha, Jharkhand, and West Bengal. A significant portion of this route now falls under the renumbered NH53.

Explanation

The time a planet takes to complete one revolution around the Sun depends on its distance from the Sun. Planets farther from the Sun have larger orbits, resulting in longer revolution periods.

Option (b) is correct: Jupiter takes the longest time among the given options to orbit the Sun, requiring approximately 4,333 days(11.86 Earth years). This is due to its significantly larger orbital path compared to the other planets listed. Hence, this is the correct answer. Options (a), (c) and (d) are incorrect:

Earth completes one revolution around the Sun in approximately 365.25 days, which is relatively short compared to the other options provided. Mars requires around 687 days(1.88 Earth years) to complete a revolution. While this is longer than Earth’s revolution time, it is still shorter than that of Jupiter. Venus has the shortest revolution period among the listed planets, taking approximately 224.7 Earth days(0.615 years) to orbit the Sun.

Explanation

Assertion (A) is true: The amount of atmospheric moisture varies with latitude because temperature differences across latitudes influence evaporation and condensation. Near the Equator, high temperatures increase evaporation rates, allowing the atmosphere to hold more water vapor, resulting in higher moisture content. In polar regions, lower temperatures reduce evaporation, leading to minimal moisture in the air. Reason (R) is true: The capacity of air to hold moisture is directly related to its temperature. Warmer air has a greater capacity to retain water vapor, while colder air can hold much less moisture. Since temperature is latitude-dependent, atmospheric moisture content is indirectly influenced by latitude. Reason (R) explains Assertion (A): Because temperature, which is dependent on latitude, determines the air’s ability to hold water vapor. This explains the variation in atmospheric moisture content across latitudes, with tropical regions being more humid and polar regions drier.

Explanation

Primary productivity refers to the rate at which plants and other photosynthetic organisms produce organic compounds from carbon dioxide and sunlight, forming the base of the food chain in an ecosystem. Assertion (A) is false: While temperate forest soils are generally richer in nutrients due to slower decomposition rates and seasonal leaf litter, tropical rainforest soils are nutrient-poor. The rapid decomposition in tropical rainforests causes nutrients to be quickly absorbed by the dense vegetation, leaving the soil itself infertile. Once the forest is cleared, the exposed soil is rapidly depleted due to erosion and leaching from heavy rains, making sustained agriculture difficult without chemical inputs. Reason (R) is true: The primary productivity (the rate at which plants convert sunlight into energy through photosynthesis) of tropical rainforests is indeed very high compared to temperate forests. This is due to consistent warm temperatures, high rainfall, and abundant sunlight year-round, which promote continuous plant growth. However, this high productivity is linked to the forest’s ecosystem, not the soil’s fertility.