NCERT Solutions Class-11 Geography Chapter-6 Landforms and their Evolutions: This article includes free NCERT Solutions Class 11 Geography Chapter 6 Landforms and their Evolutions to help students of Class 11 learn the solutions and ace their exams.
It has been developed by the subject matter experts at GFG, according to the latest CBSE Syllabus 2024-25, and guidelines to help the students of Class 11 create a solid conceptual base for Class 11 Geography Chapter 6.
Furthermore, these solutions enable students to handle various questions more easily, making their studies more manageable and efficient. In this article, we will discuss NCERT Solutions for Class 9 Geography in detail.
NCERT Solutions Class-11 Geography Chapter-6 Landforms and their Evolutions
Exercises Page No: 61-62
1. Multiple choice questions.
(i) In which of the following stages of landform development, downward cutting is dominated?
(a) Youth stage
(b) Late mature stage
(c) Early mature stage
(d) Old stage
Answer:
(a) Youth stage
(ii) A deep valley characterised by steep step-like side slopes is known as
(a) U-shaped valley
(b) Gorge
(c) Blind valley
(d) Canyon
Answer:
(d) Canyon
(iii) In which one of the following regions the chemical weathering process is more dominant than the mechanical process?
(a) Humid region
(b) Limestone region
(c) Arid region
(d) Glacier region
Answer:
(b) Limestone region
(iv) Which one of the following sentences best defines the term ‘Lapies’?
(a) A small to medium sized shallow depression
(b) A landform whose opening is more or less circular at the top and funnel shaped towards bottom (c) A landform forms due to dripping water from surface
(d) An irregular surface with sharp pinnacles, grooves and ridges
Answer:
(a) A small to medium sized shallow depression
(v) A deep, long and wide trough or basin with very steep concave high walls at its head as well as in sides is known as:
(a) Cirque
(b) Glacial valley
(c) Lateral Moraine
(d) Esker
Answer:
(a) Cirque
2. Answer the following questions in about 30 words.
(i) What do incised meanders in rocks and meanders in plains of alluvium indicate?
Answer:
Incised meanders in rocks and meanders in plains of alluvium provide clues about the past geological processes that shaped the landscape, particularly the erosive power of streams and rivers over time. These features indicate the presence of flowing water that gradually carved out these distinctive patterns in the rock formations or alluvial plains. By studying these meanders, geologists can infer the history of the land surfaces and the evolution of the river systems that created them.
(ii) Explain the evolution of valley sinks or uvalas.
Answer:
In limestone areas, surface run-off often disappears underground through swallow and sinkholes, flowing as underground streams. These streams can re-emerge downstream through cave openings. When sinkholes and dolines combine due to material slumping or cave roof collapses, they form valley sinks or Uvalas, which are elongated trenches.
(iii) Underground flow of water is more common than surface run-off in limestone areas. Why?
Answer:
In limestone areas, the underground flow of water is prevalent because limestone contains calcium carbonate. Through chemical processes like solution and precipitation deposition, surface water and groundwater form various landforms. These processes are particularly active in limestone regions, whether they occur exclusively or alongside other rock types.
(iv) Glacial valleys show up many linear depositional forms. Give their locations and names.
Answer:
Glacial valleys exhibit several linear depositional forms:
- Terminal moraines: Found at the end (toe) of glaciers.
- Lateral moraines: Formed along the sides parallel to the glacial valleys.
- Ground moraines: Result from the rapid retreat of valley glaciers, leaving an irregular sheet of till over their valley floors.
- Eskers: Formed by ice flowing over the ground, with ice forming its banks.
- Outwash Plains: Located at the foot of glacial mountains or beyond the limits of continental ice sheets.
- Drumlins: Formed beneath heavily loaded ice through fissures in the glacier.
(v) How does wind perform its task in desert areas? Is it the only agent responsible for the erosional features in the deserts?
Answer:
Winds in deserts move swiftly along the desert floors, causing turbulence when obstructed. This leads to deflation, abrasion, and impact. Deflation involves lifting and removing dust and smaller particles from rock surfaces. Sand and silt, transported by wind, abrade the land surface. Impact occurs when sand is blown into or against rock surfaces with sheer force. Wind action creates various erosional and depositional features. However, winds are not the sole agents responsible; rain or sheet wash also play significant roles.
3. Answer the following questions in about 150 words.
(i) Running water is by far the most dominating geomorphic agent in shaping the earth’s surface in humid as well as in arid climates. Explain.
Answer:
In humid regions, running water comprises overland flow as a sheet across the land surface and linear flow as streams and rivers in valleys. Erosional landforms are mostly associated with vigorous, youthful rivers. Over time, steep gradients lead to gentler stream channels, reducing velocity and promoting deposition. Sheet erosion is caused by overland flow, which can concentrate into narrow or wide paths depending on the land surface. In early stages, down-cutting dominates, removing irregularities like waterfalls. Middle stages see slower stream bed cutting and severe lateral erosion of valley sides. Terminal stages result in the formation of deltas by running water.
In arid regions, despite infrequent rainfall, desert rocks experience torrential downpours over short periods. Lack of vegetation exposes rocks to rapid mechanical and chemical weathering due to drastic temperature changes. Rainfall accelerates the removal of weathered materials. Wind and rain/sheet wash work together to transport weathered debris in deserts. Running water remains the predominant geomorphic agent shaping the Earth's surface in both humid and arid climates.
(ii) Limestones behave differently in humid and arid climates. Why? What is the dominant and almost exclusive geomorphic process in limestone areas and what are its results?
Answer:
Limestones behave differently in humid and arid climates due to variations in water availability. In humid climates, where groundwater is abundant, limestones undergo chemical weathering through processes like solution and deposition, resulting in the formation of karst topography characterized by features like caves, sinkholes, and underground rivers.
In arid climates, where groundwater is limited, physical weathering dominates, and limestone landscapes are less affected by dissolution processes.
(iii) How do glaciers accomplish the work of reducing high mountains into low hills and plains?
Answer:
Glaciers are massive sheets or linear flows of ice that slowly move over the land due to gravity. Their movement, though slow, causes significant erosion as they scrape and drag along the land, carrying debris and causing abrasion and plucking. Glacial erosion can transform tall mountains into lower hills and plains over time.
The process of erosion by glaciers is intense due to the sheer weight of the ice and the friction it generates. Rocks and debris plucked by glaciers are carried along, inflicting substantial damage to the landscape. Eventually, as glaciers move, they remove debris, lower divides, and flatten slopes, leaving behind low hills and expansive outwash plains as depositional features.
Preparation Tips for Class 11 Geography
Preparing for Class-11 Geography can be a fulfilling and beneficial experience if you follow some effective study tips. Here are some tips to help you excel in the subject:
- Understand the syllabus and topics covered in Class 11 Geography.
- Dedicate specific time each day for studying Geography and stick to a consistent study schedule.
- Take clear and organized notes while studying to facilitate easier revision later on.
- Refer to NCERT books as they are fundamental for understanding the subject.
- Use NCERT solutions to practice and deepen your understanding of concepts.
- Practice map-reading skills by using maps and identifying geographical features.
- Solve previous years’ question papers and sample papers to familiarize yourself with the exam pattern.
- Take mock tests to evaluate your knowledge and identify areas for improvement.
- Participate in group study sessions to gain different perspectives and reinforce understanding.
- Utilize visual aids such as charts and diagrams to grasp complex concepts more effectively.
- Regularly review the material you’ve learned to retain information efficiently.
- Stay updated on current affairs related to geography to broaden your understanding of the subject.
Related Links
1. CBSE Notes Class 10 Geography Chapter 4 – Agriculture
2. CBSE Notes Class 10 Geography Chapter 5: Minerals and Energy Resources
3. Manufacturing Industries Class 10 Geography Notes Chapter 6
4. CBSE Notes Class 10 Geography Chapter 7- Lifelines of National Economy
