Geography: UPSC Previous Year Questions (Prelims)

Explanation

Option (a) is correct: The Konkan Railway runs along the Konkan region of India, covering the western coastal states of Maharashtra, Goa, Karnataka, and Kerala. The railway was inaugurated in 1998 and significantly improved connectivity and economic development in these states. The Konkan Railway runs from Roha in Maharashtra to Thokur in Karnataka, covering a distance of approximately 760 km. It benefits towns and cities in Kerala situated nearby karnataka borders.

Option (b) is incorrect: Option includes Madhya Pradesh and Tamil Nadu, which are not part of the Konkan region. These states do not benefit directly from the Konkan Railway.

Option (c) is incorrect: Option lists Tamil Nadu, a southern state not served by the Konkan Railway, which runs along the western coast.

Option (d) is incorrect: Option contains Gujarat and Tamil Nadu, both of which lie outside the typical route of the Konkan Railway. Gujarat is in the north-west and Tamil Nadu in the south-east, making this option unsuitable.

Explanation

The Ahmedabad-Vadodara Expressway is a 6-lane expressway that connects the cities of Ahmedabad and Vadodara in Gujarat. It was one of India’s first expressways and significantly reduced travel time between the two cities. The expressway became operational in the late 1990s. The Mumbai-Pune Expressway is also a 6-lane expressway but was officially opened to traffic in 2002.

Explanation

Option (c) is correct: The floating islands in Manipur, known as Phoomdis, are composed of weeds, decaying vegetation, and suspended silt. These islands provide a unique habitat for the people living in the region and have been a part of the local culture and ecology for centuries. Options (a), (b) and (d) are incorrect:

Tipis are traditional conical tents used by some Indigenous tribes of North America, especially the Plains Indians. They are made from wooden poles and animal skins, and they are not related to the floating islands in Manipur. Barkhans are crescent-shaped sand dunes typically found in deserts like the Sahara Desert. They are not related to floating vegetation islands and do not exist in Manipur. Izba is a term used for traditional wooden houses or cabins, typically in Russia or Slavic regions, and it does not relate to floating islands or structures in Manipur.

Explanation

Option (a) is correct: Damodar River is the east-flow-ing river that has a rift valley due to down warping. The river flows through the Damodar Valley, which is one of the most important industrial regions in India, situated between the Chota Nagpur Plateau and the Bengal Basin. The valley formed due to geological processes like down warping and faulting, which allowed the river to cut through the region.

Option (b) is incorrect: The Mahanadi is an east-flowing river that does not flow through a rift valley. It originates from the Chhattisgarh Plateau and flows towards the east into the Bay of Bengal.

Option (c) is incorrect: The Sone River is a tributary of the Ganga and flows in the region of Bihar and Uttar Pradesh, but it does not have a rift valley.

Option (d) is incorrect: The Yamuna River is another major river in India, but it does not have a rift valley. It flows through the Himalayan foothills and North India before joining the Ganga.

Explanation

Option (b) is correct: Indian Standard Time (I.S.T.) is based on the meridian 82°30’ E, which is the reference for I.S.T. If it is noon (12:00 PM) at I.S.T., and people at another place are having 6:00 AM morning tea, that means the time difference between the two places is 6 hours. To calculate the longitude difference:

A time difference of 1 hour corresponds to a 15° difference in longitude. Therefore, a 6-hour difference corresponds to a 90° difference in longitude (6 × 15°). Since the other place is 6 hours behind I.S.T., it must be 90° to the west of the I.S.T. meridian. I.S.T. The meridian is at 82°30’ E, so moving 90° to the west brings us to 7°30’ W. Thus, the place is at a longitude of 7°30’ W.

Explanation

Option (d) is correct:

Asteroids are rocky objects that orbit the Sun, primarily found in the Asteroid Belt between Mars and Jupiter. They are remnants from the early formation of the Solar System. They vary in size from small pebbles to Ceres, which is nearly 946 km in diameter and classified as a dwarf planet. Options (a), (b) and (c) are incorrect:

Meteors do not revolve around the Sun in a fixed orbit like asteroids. They are small space debris or fragments of asteroids or comets that enter Earth’s atmosphere and burn up due to friction with the air, producing a bright streak of light (commonly called a shooting star). Comets are not confined to the region between Mars and Jupiter. Comets are icy celestial bodies that originate from the Kuiper Belt or Oort Cloud (far beyond Neptune). They follow highly elliptical orbits around the Sun and develop a glowing coma and a tail when they approach the Sun due to ice subli-mation. Meteorites are meteors that survive their passage through Earth’s atmosphere and land on Earth’s surface. Unlike asteroids they do not orbit the Sun.

Explanation

The Sun, positioned at the center of the Solar System, is the closest star to Earth, with a distance of roughly 93 million miles (approximately 8 light-minutes). Its proximity makes it crucial for life on Earth.

Option (d) is incorrect: Sirius, also known as the Dog Star, is one of the brightest stars visible from Earth. However, it is located approximately 8.6 light-years away, making it significantly farther than the Sun.

Explanation

The presence of ice caps and frozen water is the most critical condition for the potential existence of life on Mars. Water is fundamental for life as we know it. The presence of frozen water (ice caps) on Mars suggests the possibility of liquid water under certain conditions, making it the most crucial factor for life. Recent discoveries of underground water reservoirs beneath the Martian surface further highlight its importance.

Explanation

Option (b) is correct: An isopleth map is a type of thematic map that uses lines (isopleths) to connect points of equal value of a particular variable. These maps are ideal for visualizing data that changes gradually across a geographical area, like pressure. Lines (isopleths) link points of identical values, such as isobars (equal pressure), isotherms (equal temperature), or isoheights (equal altitude). Isobars, which are lines connecting points of equal atmospheric pressure, are a classic example of data visualized using an isopleth map. Options (a), (c) and (d) are incorrect:

A choropleth map uses different shades or colors to represent statistical data across predefined areas, such as population density by country or state. Chorochromatic Map also known as area-class maps, chorochromatic maps depict regions of different categories using various colors, often representing qualitative data like land use or vegetation types.For example a map showing different colors for various land cover types, such as forests, urban areas, and water bodies. Choroschematic maps simplify spatial relationships using schematic representations, often abstracting geographic details to highlight specific information. It may not adhere to strict geographic accuracy. Example: A transit map illustrating subway lines and stations without accurate geographic scaling.

Explanation

Option (b) is correct: The Indian Ocean exhibits a unique phenomenon called the monsoon drift, where seasonal wind reversals, driven by the monsoon system, significantly influence ocean currents. During the northeast monsoon (November-March), winds originate from the northeast, pushing the North Equatorial Current southwestward and westward across the Equator. In contrast, the southwest monsoon (May-September) brings winds from the southwest, causing a reversal in current direction. This cyclical shift in wind patterns directly impacts the flow of ocean currents, making the Indian Ocean distinct from other major oceans.

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

As the reversal of ocean currents in the Indian Ocean is caused by seasonal monsoon winds and not the ocean’s size. As the Indian Ocean is not landlocked though it is bordered by Asia, Africa, Australia, and the Indian subcontinent. It is because salinity variations do not primarily cause the reversal of currents.