Geomorphology: UPSC Previous Year Questions (Geography)
2 previous year UPSC Prelims questions on Geomorphology (Geography). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–2 of 2 questions
UPSC 2024Geography · Geomorphology
Q1. Consider the following statements: Statement-I: Rainfall is one of the reasons for the weathering of rocks. Statement-II: Rain water contains carbon dioxide in solution. Statement-III: Rain water contains atmospheric oxygen. Which one of the following is correct in respect of the above statements?
Explanation
Statement I is correct: Rainfall plays a key role in weathering rocks through both physical and chemical processes. For instance rainfall water seeps into cracks, causing rocks to expand and contract. Over time, this weakens the rock structure. Similarly, In colder regions, rainwater freezes inside crevices and expands. This leads to cracks and eventually breaks the rock apart. Heavy rainfall also washes away loose particles, speeding up erosion. Chemically, rainwater reacts with minerals in the rock, causing slow decomposition and dissolution. Over time, these processes break down and lead to weathering of rocks.
Statement II is correct: Rainwater absorbs carbon dioxide (CO₂) from the atmosphere, forming a weak acid solution known as carbonic acid (H₂ CO₃). This acidic rainwater reacts with minerals in rocks, leading to chemical weathering, particularly in limestone and carbonate rocks, which dissolve in acidic conditions. This process is responsible for the formation of karst landscapes, caves, and sinkholes in limestone regions.
Statement III is correct: Rainwater absorbs oxygen (O₂) from the atmosphere, which plays a crucial role in oxidation reactions in rocks containing iron and other reactive minerals. Oxygen reacts with iron-rich minerals (e.g., magnetite, pyrite) in rocks to form iron oxides (rust), which weakens the rock structure. Both Statement-II (CO₂ in rainwater) and Statement-III (O₂ in rainwater) are correct. They both explain Statement-I, as they contribute to rock weathering through chemical processes like carbonation and oxidation.
UPSC 2024Geography · Geomorphology
Q2. Consider the following: 1. Pyroclastic debris 2. Ash and dust 3. Nitrogen compounds 4. Sulphur compounds How many of the above are products of volcanic eruptions?
Explanation
A volcano is an opening or rupture in the Earth’s crust through which molten rock (magma), gases, and ash escape from beneath the surface. When magma reaches the surface, it is called lava. Volcanic eruptions can shape mountains and islands, affecting both the environment and climate. Example:
Mount Etna(Italy), Kilauea (USA) The materials that reach the Earth’s surface in volcanoes include: lava flows pyroclastic debris volcanic bombs ash and dust gases such as nitrogen compounds sulphur compounds minor amounts of chlorine, hydrogen and argon etc.
Exam tip:
You can try, The "NOT" approach for all statements, this tests the improbability of negating a statement--if denying its impact seems highly unlikely, the statement is plausibly true. For example: Can I deny Pyroclastic flow, or gases or ash are not products of Volcanoes? Likely No!, Hence all are likely true.
Answer key for these questions
Q
UPSC year
Correct answer
1
2024
(a) Both Statement-II and Statement-III are correct and both of them explain Statement-I
2
2024
(d) All four
Frequently asked questions
How many previous year UPSC questions are there on Geomorphology?
This page covers 2 previous year UPSC Prelims GS Paper-I questions on Geomorphology (Geography), asked from 2001 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Geomorphology?
Questions on Geomorphology (Geography) are available for 9 years, from 2001 to 2025. Use the Year filter to practise a single paper.
