UPSC 2020 Geography Questions with Answers

Explanation

The Jet Stream is a geostrophic wind that generally blows from west to east across the upper layers of the troposphere at an altitude of 20,000 to 50,000 feet. Air masses with different temperatures collide to form jet streams. Thus, the location of the Jet Stream’s formation is normally characterized by surface temperatures.

Statement 1 is incorrect: Jet streams exist in both the Northern and Southern Hemispheres. They typically form near the boundaries of major air masses and are driven by temperature differences and the Earth’s rotation. The Polar Jet Stream and Subtropical Jet Stream are present in both hemispheres.

Statement 2 is correct: Not all cyclones form an eye. The eye is a distinct feature of well-developed, intense tropical cyclones. In contrast, temperate cyclones do not have an eye because there is no central area where winds and rainfall are calm or inactive.

Statement 3 is incorrect: The eye of a tropical cyclone is the calm center with the lowest surface pressure and the warmest air above it. At about 12 km high, the air in the eye can be 10°C or more warmer than the surrounding air, while at the surface, it’s only 0-2°C warmer.

Explanation

Ocean Mean Temperature (OMT) represents the thermal energy in the upper layer of the ocean. It is measured up to the 26°C isotherm, which represents the depth where water temperature is consistently 26°C. OMT is a more reliable indicator than Sea Surface Temperature (SST) for predicting the Indian monsoon rainfall, as it reflects the ocean’s thermal energy more comprehensively.

Statement 1 is incorrect: OMT is measured up to the 26°C isotherm. In the southwestern Indian Ocean during January-March, the depth of the 26°C isotherm is approximately 59 meters, not 129 meters.

Statement 2 is correct: OMT, especially during the January-March period (pre-monsoon season) has been found to be a useful indicator for forecasting the Indian Summer Monsoon rainfall. Warmer OMT in this period can suggest a stronger monsoon and potentially higher rainfall, while cooler OMT may indicate a weaker monsoon. This is because the ocean’s temperature influences the amount of moisture available for the monsoon winds. Studies by the Indian Institute of Tropical Meteorology (IITM) and other scientific bodies have shown a strong correlation between OMT and monsoon performance.

Explanation

Statement 1 is correct: In India, the important pulse crops grown in winter (rabi) are chickpea, lentil, lathyrus, field pea and kidney bean. However, green gram, black gram and cowpea are grown in both spring and rainy season. Black gram (Urad dal) can be cultivated in both kharif (monsoon) and rabi (winter) seasons in India, making it a versatile crop in the country’s agricultural cycle.

Statement 2 is incorrect: According to the Directorate of Economics and Statistics (DES), the share of pulse production in 2018-19 was as follows: Tur (15.34%), Gram (43.29%), Moong (Green gram, 10.04%), Urad (Black gram, 13.93%), Lentil (6.67%), and other pulses (10%). Green gram alone does not account for nearly half of India’s total pulse production.

Statement 3 is incorrect: Over the past three decades, both kharif pulses and rabi pulses have experienced increased production due to improved agricultural practices, increased area under cultivation, and better support for pulse farming.

Explanation

Option (a) is correct: Cotton is India’s most important fiber crop, accounting for about 25% of the world’s cotton production. Cotton growing condition requirements:

Temperature and climate: Cotton flourishes in a subtropical climate with optimal temperatures ranging from 21°C to 30°C. Rainfall: Cotton needs 50 to 100 cm of rainfall during its growing period, but excessive or waterlogged conditions can negatively affect its growth. Soil Type: Cotton grows best in light, well-drained, moisture-retaining soils, especially the black cotton soil of the Deccan Plateau, which has high moisture-retention capacity. Frost-Free Days: Requires at least 210 frost-free days and bright sunshine to complete its life cycle. Growing Season: It is a kharif crop and typically takes 6 to 8 months to mature Top Cotton Producing States: Gujarat > Maharashtra > Telangana > Andhra Pradesh > Rajasthan. Options (b), (c) and (d) are incorrect:

Jute: Requires high rainfall (150-200 cm) and humid weather, not subtropical conditions. Sugarcane: Requires higher rainfall (75-200 cm) and thrives mainly in tropical regions. Tea: Requires cool, humid conditions, heavy rainfall (150-300 cm), and acidic soils, unlike the drier conditions needed for cotton.

Explanation

In India, minerals are classified as major minerals and minor minerals under the Mines and Minerals (Development and Regulation) Act, 1957. Major minerals are those specified in the First Schedule of the Act and are under the regulatory control of the central government. Minor minerals are defined under Section 3(e) of the Act and are regulated by state governments.

Option (d) is correct: The following are Major minerals:

Chromite is an oxide mineral of chromium and iron and is the primary source for chromium. It is extensively used in metallurgy, refractory materials, and chemicals. Kyanite is a typically blue silicate mineral used in refractory and ceramic products. Sillimanite is an alumino-silicate mineral used in high-temperature ceramics and refractories. Bentonite is a type of clay formed from volcanic ash and is primarily used in drilling mud, binder, purifier, and absorbent applications. In India, bentonite is officially classified as a minor mineral.

Explanation

Option 1 is correct: Nagarhole National Park is located in the Kodagu and Mysore districts of Karnataka. The Nagarahole River flows through the park which joins the Kabini River which also is a boundary between Nagarahole and Bandipur National Park.

Option 2 is incorrect: Papikonda National Park is located in the East Godavari and West Godavari districts of Andhra Pradesh. It lies in the Godavari River Basin, not the Cauvery Basin.

Option 3 is correct: Sathyamangalam Tiger Reserve (STR) is located at the confluence region of Western and Eastern Ghats, in the Erode district of the state of Tamil Nadu. In the northern part of Erode district, the Palar river flows and drains into the Cauvery river. The Bhavani River, a major tributary of the Cauvery, flows through this region.

Option 4 is correct: Kabini river, a tributary of the Cauvery river flows through the Wayanad Wildlife Sanctuary.

Explanation

The Siachen Glacier lies to the north of the Nubra Valley, which is situated in the northern part of the Ladakh region of India. It is located in the Karakoram Range in the northernmost part of the Indian subcontinent. It is positioned in the region claimed by both India and Pakistan and is the longest glacier in the world outside the polar regions, spanning approximately 76 kilometers (47 miles).The Nubra Valley, located at the confluence of the Shyok and Nubra Rivers, is a key geographical feature in the vicinity of the Siachen Glacier. It is also the world’s highest battlefield.

Explanation

Statement 1 is incorrect: The Mekong River originates in the icy headwaters of the Tibetan highlands. It flows through several countries in Southeast Asia, including China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. It does not flow into the Andaman Sea. It empties into the South China Sea through the Mekong Delta in southern Vietnam.

Statement 2 is incorrect: The Thames flows into the North Sea, not the Irish Sea. It is a major river in England, flowing through London. The Thames flows into the North Sea via the Thames Estuary.

Statement 3 is correct: The Volga River is the longest river in Europe. It runs through Russia with its delta flowing into the Caspian Sea just south of the Kazakhstan border.

Statement 4 is correct: The Zambezi River, which means "Great River" in the Tonga language is one of Africa’s most bio-diverse rivers, and the fourth-largest river basin on the continent. It flows into to the Indian Ocean. The river is known for the Victoria Falls, one of the largest and most famous waterfalls in the world.