Basic Quiz – 24 October 2026 | Geography

Correct Answer: (b) 1, 2 and 4 only

Explanation:

• Statement 1 is correct: During the Northern Hemisphere summer, the ITCZ shifts northward towards the Indian subcontinent, contributing to the formation of the monsoon trough. This low-pressure zone helps attract moisture-bearing winds.
• Statement 2 is correct: The Mascarene High is a subtropical high-pressure system over the southern Indian Ocean, near the Mascarene Islands. The pressure gradient between this high-pressure region and the low-pressure areas over the Indian subcontinent helps drive cross-equatorial winds that become part of the southwest monsoon circulation.
• Statement 3 is incorrect: The Tropical Easterly Jet is primarily a summer phenomenon associated with the southwest monsoon. During winter, the Subtropical Westerly Jet influences weather over northern India.
• Statement 4 is correct: A positive IOD is characterised by relatively warmer sea-surface temperatures in the western Indian Ocean and cooler temperatures in the eastern Indian Ocean. It can favour Indian monsoon rainfall and sometimes counteract the adverse influence of El Niño.

Remember for Prelims:

• The Southwest Monsoon generally occurs from June to September.
• The Northeast Monsoon is particularly important for rainfall in Tamil Nadu during October to December.
• El Niño refers to abnormal warming of the central and eastern equatorial Pacific Ocean.
• La Niña refers to abnormal cooling of the central and eastern equatorial Pacific Ocean.
• The Somali Jet, also called the Findlater Jet, is a low-level cross-equatorial jet associated with the southwest monsoon.

Correct Answer: (a) 1, 2 and 3 only

Explanation:

• Statement 1 is correct: The Indus originates in the Tibetan Plateau near the Kailash region and flows through Ladakh before entering Pakistan.
• Statement 2 is correct: The Brahmaputra is called the Yarlung Tsangpo in Tibet. It enters Arunachal Pradesh as the Siang or Dihang and subsequently receives major tributaries, including the Dibang and Lohit.
• Statement 3 is correct: The Teesta originates in the eastern Himalayan region of Sikkim. It flows through Sikkim and West Bengal before entering Bangladesh, where it joins the Brahmaputra-Jamuna river system.
• Statement 4 is incorrect: The Chenab is formed by the confluence of the Chandra and Bhaga rivers at Tandi in Himachal Pradesh. The Beas joins the Sutlej at Harike in Punjab.

Remember for Prelims:

• Indus tributaries: Jhelum, Chenab, Ravi, Beas and Sutlej.
• Brahmaputra tributaries: Subansiri, Kameng, Manas, Dibang and Lohit.
• Ganga headstreams: Bhagirathi and Alaknanda meet at Devprayag.
• Chenab: Formed by the Chandra and Bhaga rivers.
• Teesta: Flows through Sikkim, West Bengal and Bangladesh.

Correct Answer: (c) 1, 2 and 4 only

Explanation:

• Statement 1 is correct: The Humboldt Current, also called the Peru Current, is a cold eastern-boundary current flowing northward along the western coast of South America. It is associated with coastal upwelling and nutrient-rich waters.
• Statement 2 is correct: The Benguela Current is a cold current flowing northward along southwestern Africa. It contributes to atmospheric stability and limited rainfall, supporting the arid conditions of the Namib Desert.
• Statement 3 is incorrect: The Gulf Stream is a warm ocean current flowing from the region of the Florida Straits along the eastern coast of North America and into the North Atlantic.
• Statement 4 is correct: The warm Kuroshio and cold Oyashio currents meet in the northwestern Pacific near Japan. Their interaction contributes to nutrient availability and highly productive marine ecosystems.

Remember for Prelims:

• Cold currents: Humboldt, Benguela, California, Canary, Labrador and Oyashio.
• Warm currents: Gulf Stream, Kuroshio, Brazil, Agulhas and East Australian Current.
• Cold currents along western continental margins often contribute to coastal aridity.
• Coastal upwelling brings nutrient-rich deep water towards the ocean surface.
• Major fishing grounds are commonly associated with upwelling zones and regions where contrasting water masses interact.

Correct Answer: (d) 1, 2 and 4 only

Explanation:

• Statement 1 is correct: Black soils, also called regur soils, are extensively found in the Deccan Plateau. They are associated with weathering of basaltic rocks and contain a high proportion of clay, giving them considerable moisture-retention capacity.
• Statement 2 is correct: Laterite soils form in tropical and subtropical regions experiencing high temperatures, substantial rainfall and intense leaching. They are often enriched in iron and aluminium oxides.
• Statement 3 is incorrect: Alluvial soils are found not only in the Indo-Gangetic Plains but also in major river valleys, coastal plains and deltaic regions of peninsular India.
• Statement 4 is correct: Red and yellow soils commonly develop from crystalline igneous and metamorphic rocks, particularly in areas of low to moderate rainfall. Their reddish colour is associated with iron oxides.

Remember for Prelims:

• Black soil: Cotton cultivation, high clay content, moisture retention.
• Alluvial soil: Khadar (newer alluvium) and Bhangar (older alluvium).
• Laterite soil: Intense leaching, iron and aluminium enrichment.
• Red soil: Iron oxides responsible for reddish colour.
• Arid soil: Common in western Rajasthan, generally sandy and low in organic matter.

Correct Answer: (a) 1, 2 and 3 only

Explanation:

• Statement 1 is correct: The Himalayas developed through the collision of the Indian and Eurasian continental plates following the closure of the Tethys Ocean. The ongoing convergence contributes to the region’s high seismic activity.
• Statement 2 is correct: The Mid-Atlantic Ridge is a divergent plate boundary where tectonic plates move apart and magma rises to create new oceanic crust.
• Statement 3 is correct: The Pacific Ring of Fire is a major zone of earthquakes and volcanic activity surrounding much of the Pacific Ocean. Subduction zones are responsible for many of its volcanic arcs and powerful earthquakes.
• Statement 4 is incorrect: Transform boundaries involve lateral movement of plates past one another. They generally neither create nor destroy significant amounts of lithosphere. New oceanic crust is formed at divergent boundaries.

Remember for Prelims:

• Divergent boundary: Plates move apart; new crust may form.
• Convergent boundary: Plates move towards one another; subduction or continental collision may occur.
• Transform boundary: Plates slide horizontally past one another.
• San Andreas Fault: A major transform plate boundary in California.
• Andes Mountains: Associated with the subduction of the Nazca Plate beneath the South American Plate.
• Himalayas: Continental collision zone associated with frequent earthquakes.
• Mid-Atlantic Ridge: Major submarine mountain system associated with seafloor spreading.