UPSC Previous Year Questions (Prelims): Geomorphology | Geography for UPSC CSE PDF Download

Correct Answer is Option (d)
All four of the listed substances are products of volcanic eruptions:

• Pyroclastic debris: This refers to fragments of volcanic rocks, lava, and ash ejected during explosive volcanic eruptions.
• Ash and dust: Volcanic eruptions release large amounts of ash and fine dust particles into the atmosphere. These are formed when lava and magma break apart due to volcanic activity.
• Nitrogen compounds: Volcanic eruptions can release various gases, including nitrogen compounds like nitric oxide (NO) and nitrogen dioxide (NO₂), which can contribute to atmospheric pollution.
• Sulphur compounds: Volcanic eruptions are also significant sources of sulfur compounds, particularly sulfur dioxide (SO₂), which can have impacts on the climate and contribute to acid rain.

Thus, the correct answer is Option D (All four).

Correct Answer is Option (b)

• Central Asia – Vosges – Fold mountain:
  Incorrect. The Vosges mountain range is in Europe, not Central Asia, and is indeed a fold mountain, but the region is wrong.
• Europe – Alps – Block mountain:
  Incorrect. The Alps are fold mountains, not block mountains.
• North America – Appalachians – Fold mountain:
  Correct. The Appalachians in North America are indeed fold mountains.
• South America – Andes – Fold mountain:
  Correct. The Andes in South America are also fold mountains

So, two rows are correctly matched (rows 3 and 4), not just one. Hence, the correct answer is Option B (Only two).

Correct Answer is Option (d)
The Rann of Kutch is the best example of repeated falls in sea level, giving rise to extensive marshland. It is a large, salt marshy area located in the Kutch district of Gujarat. Over the centuries, the region has experienced repeated fluctuations in sea level, leading to the formation of the Rann, a seasonal marshland that is submerged during the monsoon season and becomes dry and cracked during the dry season. The phenomenon is linked to tectonic activity and changes in sea levels.
The other options are not as closely related to the phenomenon of repeated sea level fluctuations:

• Bhitarkanika Mangroves are coastal wetlands, but they are primarily influenced by tidal actions and river discharge rather than repeated sea level changes.
• Marakkanam Salt Pans are salt production areas, not marshlands created by sea level fluctuations.
• Naupada Swamp is a coastal marsh but not known for being primarily a result of repeated sea level falls.

Correct Answer is Option (d)

Ilmenite and rutile are both important ores of titanium. These minerals are rich in titanium dioxide (TiO₂) and are primarily used in the production of titanium metal and its compounds. India has significant deposits of ilmenite and rutile, particularly along its coastal regions, which are mined for their titanium content.

• Ilmenite is the most common titanium ore and is primarily used to extract titanium metal, which is used in industries such as aerospace, automotive, and in manufacturing pigments.
• Rutile is another important source of titanium and is also used in the production of titanium dioxide, a key component in paints, coatings, and other products.

Correct Answer is Option (c)
The Gandikota Canyon, often referred to as the "Grand Canyon of India," was created by the Pennar River. The river has carved deep gorges and valleys through the rugged terrain of the Eastern Ghats, forming this spectacular canyon located in the Kadapa district of Andhra Pradesh.
The other rivers mentioned are not responsible for the formation of Gandikota Canyon:

• Cauvery flows in Tamil Nadu and Karnataka.
• Manjira is a tributary of the Godavari.
• Tungabhadra is a major river in the region but does not form the Gandikota Canyon.

Thus, the correct answer is Option C (Pennar).

Correct Answer is Option (b)

• Monazite is a source of rare earths:
  This is correct. Monazite is a mineral that contains a significant amount of rare earth elements, which are used in various high-tech industries.
• Monazite contains thorium:
  This is correct. Monazite is rich in thorium, a radioactive element that is used in nuclear energy production.
• Monazite occurs naturally in the entire Indian coastal sands in India:
  This is incorrect. While monazite is found in the coastal sands of India, it does not occur throughout the entire coastline. Major deposits are found in certain coastal regions, especially in Kerala, Tamil Nadu, and Odisha.
• In India, Government bodies only can process or export monazite:
  This is correct. The processing and export of monazite are regulated by the Government of India due to its thorium content and the associated nuclear concerns. Only authorized government agencies or entities can handle monazite.

Thus, the correct answer is Option B (1, 2, and 4 only).

Correct Answer is Option (b)

The black cotton soil of India, also known as Regur soil, is primarily formed due to the weathering of fissure volcanic rock, which is rich in iron and magnesium. These soils are found in regions where volcanic eruptions have occurred, particularly in areas like Maharashtra, Madhya Pradesh, and Gujarat. The volcanic rocks, when weathered, break down to form a rich, dark-colored soil that is highly fertile and ideal for growing cotton, hence the name "black cotton soil." Option B (fissure volcanic rock) is the correct answer because this type of rock, when weathered, produces the characteristic black cotton soil.

Correct Answer is Option (b)

• Nagavali and Vamsadhara are the rivers that rise from the Eastern Ghats.
• Nagavali originates from the hill ranges of the Eastern Ghats in the state of Odisha.
• Vamsadhara also originates from the Eastern Ghats, in the region of Andhra Pradesh.

On the other hand, Brahmani and Subarnarekha originate from different regions:

• Brahmani originates from the confluence of the Sankh and Koel rivers in Jharkhand, which are part of the Chhotanagpur Plateau, not the Eastern Ghats.
• Subarnarekha rises from the Ranchi Plateau in Jharkhand.

Thus, the correct answer is Option B (2 and 4).

Correct Answer is Option (d)

The Siachen Glacier is located in the Karakoram Range in the northern part of India and is situated north of the Nubra Valley in Ladakh. The glacier lies at an elevation of about 5,400 meters (17,700 feet) above sea level and is the largest glacier in the world outside the polar regions.

• The Nubra Valley lies to the south of the Siachen Glacier, and the glacier is situated to the north of it. The valley is separated from the glacier by the Saltoro Range, which forms part of the Line of Control (LoC) between India and Pakistan.
• The glacier is not to the east of Aksai Chin, east of Leh, or north of Gilgit, so these options are incorrect.

Correct Answer is Option (c)

• Mekong River: The Mekong River does not flow into the Andaman Sea; it flows into the South China Sea through the Mekong Delta. Hence, Pair 1 is incorrect.
• Thames River: The Thames River does not flow into the Irish Sea; it flows into the North Sea via the Thames Estuary. Hence, Pair 2 is incorrect.
• Volga River: The Volga River flows into the Caspian Sea, which is correct. Hence, Pair 3 is correct.
• Zambezi River: The Zambezi River flows into the Indian Ocean, specifically through the Mozambique Channel. Hence, Pair 4 is correct.

Thus, the only correct pairs are 3 (Volga-Caspian Sea) and 4 (Zambezi-Indian Ocean).

Correct Answer is Option (a)
Barren Island volcano became active again in March 1991. The second phase of eruptions started in 1995. So it means the third statement is wrong, by elimination, we have the answer (a) only 1.

Correct Answer is Option (c)
Continental Drift has affected the evolution of animals, the world's geographical positions, and the world's climates. The split of the original super landmass Pangea into Gondwanaland and the Laurasia created new geographical/ climatic regions. The rearrangement and displacement of huge landmasses have helped create the diversity which we see in modern-day species. The final stages of evolution of Genus Homo occur in the last 3 glacial cycles.

Correct Answer is Option (c)
The core of the earth is made up of nickle and iron.

Correct Answer is Option (d)
Volcanic mountain. St. Helen is located in United States of America.

Correct Answer is Option (c)
Quartzite is a metamorphosed form of sandstone.

Correct Answer is Option (a)
The basaltic rock found in the Baltic sea is transported by glaciers.

Correct Answer is Option (d)
All the statements are true about the sedimentary rock.

Correct Answer is Option (d)
Anthracite is a dense, shiny coal that has a high carbon content. Very little volatile matter is present in it. It gives a clean flame while burning. Anthracite contains 91% of carbon; is very little volatile and has almost smokeless burning.