Samacheer Kalvi Class 7 Social Science Solutions Term 1 Chapter 2 Landforms

S.No	Natural Agents	Landforms
		Erosion	Deposition
1	River
2	Glacier
3	Wind
4	Sea wave

Answer:

S.No	Natural Agents	Erosion	Deposition
1.	River	V-Shaped Valley	Alluvial Fan
2.	Glacier	Arete	Moraine
3.	Wind	Inselberg	Barchan
4.	Sea wave	Cliff	Lagoon

In simple words: This table categorizes landforms based on whether they are created by erosion (wearing away) or deposition (building up) from different natural agents like rivers, glaciers, wind, and sea waves. For example, rivers erode to make V-shaped valleys and deposit to make alluvial fans.

🎯 Exam Tip: When filling such tables, identify one erosional and one depositional landform for each agent, focusing on distinct and representative examples.

 

Activity:

Find out the names of a few rivers of the world that form a delta with the help of the Atlas.

Answer:1. Amazon Delta 2. Danube Delta 3. Ebro Delta 4. Fly Delta 5. Ganges-Brahmaputra Delta 6. Godavari Delta 7. Irrawaddy Delta 8. Indus River Delta 9. Nile Delta 10. Yellow River Delta.
In simple words: Many big rivers around the world form deltas where they meet the sea, like the Nile, Amazon, and Ganges-Brahmaputra. These deltas are formed from the soil and sand the river carries.

🎯 Exam Tip: For activities requiring examples, choose a diverse set from different continents or regions to demonstrate broad knowledge.

7th Social Science Guide Landforms Additional Important Questions and Answers

I. Choose the Correct Answer:

 

Question 1. The place of the origin of the river is ...................................
(a) Source
(b) mouth
(c) Lake
(d) delta
Answer: (a) Source
In simple words: The source is the exact spot where a river begins, usually a spring, lake, or melting glacier. It is the very starting point of the river's flow.

🎯 Exam Tip: Clearly distinguish between a river's source (beginning) and its mouth (end) in your mind to avoid confusion.

 

Question 2. The highest waterfalls in South America is ...................................
(a) Niagara
(b) joke
(c) Angel
(d) Kuttralam
Answer: (c) Angel
In simple words: Angel Falls, located in Venezuela, is the tallest waterfall in South America and indeed the world. Its water drops from a very high cliff.

🎯 Exam Tip: When answering questions about "highest" or "largest" geographical features, ensure you recall the correct name and continent.

 

Question 3. ...................................falls is located on the border between Canada and U.S.A.
(a) Jake
(b) Niagara
(c) Angel
(d) contra lame
Answer: (b) Niagara
In simple words: Niagara Falls is a famous group of large waterfalls on the border between the United States and Canada. It is known for its immense power and beauty.

🎯 Exam Tip: Memorize the locations of major world landmarks, like Niagara Falls, to common geographical borders.

 

Question 4. Victoria Falls located in which continent
Answer: Africa
In simple words: Victoria Falls is a very large waterfall located in Africa, on the Zambezi River. It is a significant natural wonder of the continent.

🎯 Exam Tip: For continent-specific questions, double-check your knowledge of global geography to pinpoint the correct location.

 

Question 5. Meander River flows in ...................................
(a) Bengal
(b) Peru
(c) Asia minor
(d) England
Answer: (c) Asia minor
In simple words: The Meander River, famous for its winding course, is found in Asia Minor, which is a historical region primarily in modern-day Turkey. Its name is the origin of the English word 'meander'.

🎯 Exam Tip: Connect the origin of geographical terms (like "meander" from the Meander River) to their actual locations for an enriched understanding.

 

Question 6. Corride cirque is located in ...................................
(a) Holland
(b) Scotland
(c) Iceland
(d) New Zealand
Answer: (b) Scotland
In simple words: A cirque is a bowl-shaped hollow in mountains. In Scotland, it is known by the name "corrie". It is a landform specifically shaped by glacial erosion in mountainous areas.

🎯 Exam Tip: Remember that some geographical terms, like cirque, have regional names; "corrie" is the Scottish term for a cirque.

 

Question 7. The crescent-shaped sand dunes are called ...................................
(a) Barchens
(b) Meander
(c) Lagoon
(d) delta
Answer: (a) Barchens
In simple words: Barchens, also spelled barchans, are sand dunes that are shaped like a crescent moon. These dunes are typically found in deserts and are formed by wind blowing in one main direction.

🎯 Exam Tip: When identifying types of sand dunes, remember that "barchan" specifically refers to the crescent shape formed by wind action.

 

Question 8. The collection of sediments from all the mouths of river forms
(a) Lagoons
(b) delta
(c) Meander
(d) Valley
Answer: (b) delta
In simple words: When a river reaches the sea, it slows down and drops all the soil and sand it carried, forming a new land area called a delta. Deltas are typically very fertile.

🎯 Exam Tip: Remember that deltas are formed by deposition, specifically at the river mouth where the flow slows down significantly.

 

Question 9. The largest beach in the world is
(a) Marina
(b) vembanad
(c) Silica
(d) Miami
Answer: (d) Miami
In simple words: Miami Beach in the USA is known for being one of the longest beaches in the world. It is a famous stretch of sand.

🎯 Exam Tip: Always pay attention to details like location and specific features when answering questions about record-breaking natural formations.

 

Question 10. A shallow stretch of water partially separated from the sea is
(a) Lagoon
(b) delta
(c)
(d) Barchens
Answer: (a) Lagoon
In simple words: A lagoon is a calm, shallow area of water near the sea but mostly closed off from it, often by a sand barrier. These bodies of water can be very biologically diverse.

🎯 Exam Tip: Understand the key characteristic of a lagoon: it's a body of water near the sea, but mostly enclosed or protected by a natural barrier.

II. Fill in the blanks:

 

Question 1. Rivers generally originate from a .................... or ....................
Answer: mountain, hill
In simple words: Rivers usually start flowing from high places like mountains or hills. These high areas gather water that flows downwards.

🎯 Exam Tip: Remember that high ground is where water often collects and begins its downward path, forming rivers and streams.

 

Question 2. The raised river banks are called ....................
Answer: Levees
In simple words: Levees are natural raised banks along a river that form when floods leave behind mud and silt. They help to contain the river's flow.

🎯 Exam Tip: Levees are important natural formations that can prevent rivers from overflowing their banks during high water levels.

 

Question 3. An active agent of erosion and deposition in the deserts is ....................
Answer: wind
In simple words: In deserts, wind is the main natural force that changes the land, moving sand and dust around. It creates features like sand dunes.

🎯 Exam Tip: Think about the unique conditions of a desert - lack of water means wind plays a dominant role in shaping its features.

 

Question 4. An isolated residual hill, stand like a pillar with rounded tops are ....................
Answer: Inselbergs
In simple words: Inselbergs are tall, lonely hills with round tops that stand alone in flat areas. They form when softer rocks around them wear away.

🎯 Exam Tip: Inselbergs are striking landforms that show how harder rocks can resist erosion while softer surrounding rocks are worn away.

 

Question 5. Northern China loess deposits are brought from the .................... Desert.
Answer: Gobi
In simple words: The Gobi Desert is where the fine, yellowish soil (loess) that covers Northern China comes from, carried by strong winds. These deposits make the soil very fertile.

🎯 Exam Tip: Loess deposits are a result of wind erosion and deposition, creating fertile soils in distant areas, often far from the source of the sand.

 

Question 6. A part of land adjoining near the sea is called ....................
Answer: sea coast
In simple words: The land right next to the sea or ocean is called the sea coast. This is the area where land and water meet.

🎯 Exam Tip: The coast is where land meets the ocean, and it's constantly changed by waves and currents.

 

Question 7. The boundary of the sea coast, where land meets water is ....................
Answer: coastline
In simple words: The coastline is the exact line where the land touches the water of the sea or ocean. This line moves with tides.

🎯 Exam Tip: The coastline is a dynamic boundary, constantly shaped by natural forces like waves and tides, and human activity.

 

Question 8. ....................are steep rockfaces formed when the sea waves dash against them.
Answer: sea cliffs
In simple words: Sea cliffs are tall, rocky walls next to the ocean, made by waves hitting the land over and over again. They show the power of the sea.

🎯 Exam Tip: Sea cliffs are clear examples of coastal erosion, showing the power of the ocean to shape landforms over time.

 

Question 9. The wall-like feature in the sea is ....................
Answer: stacks
In simple words: Stacks are tall, narrow rocks that stand alone in the sea, looking like walls. They are often the last parts of a headland left after erosion.

🎯 Exam Tip: Stacks represent the final stage of coastal erosion when a headland has been worn down to isolated pillars of rock.

 

Question 10. The second largest beach in the world is the .................... beach in Chennai.
Answer: Marina
In simple words: Marina Beach in Chennai, India, is known as the second-longest urban beach in the world. It is a popular spot for locals and tourists.

🎯 Exam Tip: Recognize that specific geographic features often have unique characteristics, like Marina Beach being one of the world's longest urban beaches.

 

Question 11. Moraines ....................deposition.
Answer: glacial
In simple words: Moraines are landforms made from rocks and soil that have been moved and then dropped off by a glacier. They show where glaciers have moved.

🎯 Exam Tip: Moraines are key indicators of past glacial activity and help geologists understand ice age movements and glacial limits.

 

Question 12. ....................is a stream or river that flow into and joins the main river.
Answer: Tributary
In simple words: A tributary is a small river or stream that flows into and joins a larger main river. It adds water to the main river.

🎯 Exam Tip: Understand the difference: a tributary joins a main river, while a distributary branches off from it.

 

Question 13. The collection of sediments from all the mouths of river forms ....................
Answer: delta
In simple words: The sediments dropped by a river at its many mouths create a landform called a delta. This happens when the river water slows down.

🎯 Exam Tip: Deltas are fertile, low-lying areas formed by river sediments, often providing rich agricultural land and unique ecosystems.

 

Question 14. ....................is the armchair shaped depression formed by glacial erosion.
Answer: Cirque
In simple words: A cirque is a deep, bowl-shaped hollow on a mountainside that has been scooped out by a glacier. Snow and ice often gather there.

🎯 Exam Tip: Cirques are characteristic features of glaciated mountain regions, often marking the starting point of a glacier's flow.

 

Question 15. The process of leveling of highlands is called ....................
Answer: Gradation
In simple words: Gradation is the natural process that smooths out land by wearing down high areas and filling in low ones. It constantly changes the Earth's surface.

🎯 Exam Tip: Gradation is an important geological process that works to reduce relief and create a more uniform land surface through erosion and deposition.

III. Match the following.

 

Answer:
1. Meander River - (b) River curves
2. Valley Glacier - (d) Alps mountain
3. Continental Glacier - (a) Antarctica
4. Scotland - (c) Corrie cirque
In simple words: This table correctly pairs different types of glaciers and rivers with their characteristics or locations. For example, a Meander River makes curves, and Continental Glaciers are found in places like Antarctica.

🎯 Exam Tip: For matching questions, carefully read both columns and look for direct relationships or key characteristics to ensure correct pairings.

IV. Consider the following statement and tick (√) the appropriate answer:

 

Question 1. Assertion (A): The deltas are formed near the mouth of the river. Reason (R): The velocity of the river becomes slow when it approaches the sea.
(a) Both A and R are correct explanations of A
(b) A and R are correct but A does not explain R
(c) A is incorrect but R is correct
(d) Both A and R are incorrect
Answer: (a) Both A and R are correct explanations of A
In simple words: Both the statement about deltas forming at river mouths and the reason about the river slowing down near the sea are true. The slowing river drops its sediments, which explains why deltas are built there.

🎯 Exam Tip: When dealing with assertion-reason questions, first check if both statements are individually true, then assess if the reason correctly explains the assertion.

 

Question 2. Assertion (A) : Sea arches in turn become Sea stacks. Reason (R) : Sea Stacks are the results of wave deposition,
(a) Both A and R are correct explanations of A
(b) A is correct and R is wrong
(c) A is wrong and R is correct
(d) Both A and R are wrong
Answer: (b) A is correct and R is wrong
In simple words: It is true that sea arches can turn into sea stacks when their tops collapse. However, the reason given is wrong because sea stacks are formed by waves wearing away rock (erosion), not by waves dropping material (deposition).

🎯 Exam Tip: Distinguish carefully between erosion (wearing away) and deposition (building up) processes in landform creation, especially for coastal features.

V. Answer the following:

 

Question 1. Define erosion.
Answer: Erosion is the natural process where the surface of the Earth, including rocks and soil, is worn away and transported by forces like water, wind, ice, and gravity. This continuous action reshapes the landscape over time, creating new features and reducing others.
In simple words: Erosion is when natural forces like water or wind slowly wear away and carry off soil and rocks from the land.

🎯 Exam Tip: Defining geological terms accurately requires mentioning both the 'wearing away' and 'transportation' aspects of the process.

 

Question 2. How waterfalls are formed?
Answer: Waterfalls are formed when a river's water flows over a sudden drop or vertical step in its bed. This often happens because softer rock layers are eroded away faster than harder rock layers above them. The constant force of the water further deepens the plunge pool at the base. A well-known example is the Courtallam Falls.
In simple words: Waterfalls happen when a river flows over a tall step. This step forms when soft rocks in the river bed are worn away, leaving hard rocks higher up.

🎯 Exam Tip: When explaining formation, always mention the key factors: a vertical drop, differential erosion (soft vs. hard rock), and give an example if possible.

 

Question 3. Bring out the feature of Meanders with examples.
Answer: When a river flows onto a flat plain, its current slows down, causing it to form large, looping bends known as meanders. These curves develop due to the river eroding its outer banks and depositing sediment on its inner banks, creating a winding path. This natural process constantly shifts the river's course. An example of this can be seen with the meanders along the River Vellar in Tamil Nadu.
In simple words: When a river moves across flat land, it makes big curves called meanders. The River Vellar in Tamil Nadu shows these curves clearly.

🎯 Exam Tip: Explain both the 'what' (twists and turns) and the 'why' (river slowing down on plains, erosion/deposition) when describing meanders, and include an example.

 

Question 4. Define Glacier.
Answer: A glacier is a massive, slow-moving river of ice that forms over many years from accumulated snow that has compacted into solid ice. It flows downhill due to the force of gravity, carving out valleys and shaping landscapes as it moves. Glaciers are powerful agents of erosion.
In simple words: A glacier is a huge mass of ice that moves very slowly down a mountain or valley because of gravity.

🎯 Exam Tip: Key points for defining a glacier are 'large body of ice' and 'slowly moving due to gravity and its own weight'.

 

Question 5. What is inselberg?
Answer: An inselberg is an isolated hill or mountain that rises abruptly from a relatively flat surrounding plain. It often has a rounded top and appears like a pillar, formed by the long-term erosion of softer rock, leaving behind harder, more resistant rock. They are commonly found in desert regions, such as the Kalahari Desert.
In simple words: An inselberg is a lone, pillar-like hill with a round top that stands out in a flat area, formed when the surrounding softer rock erodes away.

🎯 Exam Tip: Remember that inselbergs are resistant rock formations left standing after extensive erosion of surrounding softer terrain, often indicating long-term geological processes.

 

Question 6. What is a Sand bar?
Answer: A sandbar is an elongated deposit of sand or mud that forms in a sea, lake, or river, running parallel to the coast or a riverbank. These underwater or partially submerged ridges are created by the movement of water currents and waves, often acting as natural breakwaters. They can often be seen near beaches.
In simple words: A sandbar is a long pile of sand, often under water or just above it, created by water currents in a sea or river.

🎯 Exam Tip: Distinguish sandbars from beaches; sandbars are typically submerged or partially submerged ridges created by currents, not necessarily continuous land access points.

VIII. Answer in a paragraph:

 

Question 1. What are the forces of landforms – Explain.
Answer: Landforms are shaped by two main types of forces: endogenic (internal) and exogenic (external) processes. Endogenic forces, which come from inside the Earth, cause parts of the Earth's surface to lift up or sink down, such as during mountain building or volcanic eruptions. Exogenic forces, on the other hand, act on the Earth's surface, constantly wearing it down through erosion (like by wind, water, and ice) and then rebuilding it through deposition. These two forces work together in a continuous cycle to create and change the Earth's diverse landscapes.
In simple words: Landforms are shaped by two forces: endogenic forces from inside Earth (like uplift of mountains) and exogenic forces from outside (like wind and water wearing down the land).

🎯 Exam Tip: Remember that endogenic forces build up landforms, while exogenic forces wear them down, creating a continuous cycle of change on Earth's surface.

 

Question 2. Describe Delta.
Answer: A delta is a triangular landform created at the mouth of a river where its main stream splits into several smaller channels, called distributaries, as it enters a larger body of water like an ocean or a sea. This happens because the river's flow slows down significantly, causing it to deposit large amounts of sediment (mud, sand, and silt). Deltas are typically very fertile areas, making them highly suitable for agriculture and often supporting rich ecosystems.
In simple words: A delta is a triangle-shaped piece of land at the end of a river, where the river drops its mud and sand before flowing into the sea.

🎯 Exam Tip: When describing a delta, include its location (river mouth), how it forms (sediment deposition), and its common shape (triangular or fan-shaped).

 

Question 3. How sea caves are formed?
Answer: Sea caves are formed by the continuous, powerful action of sea waves crashing against rocky coastlines. Over time, these waves exploit weaknesses and cracks in the rocks, enlarging them through hydraulic action and abrasion. This constant battering slowly carves out hollows in the cliff face, leading to the formation of sea caves. The process is slow but relentless.
In simple words: Sea waves hit rocks over and over again, causing cracks to grow bigger until hollow spaces, or sea caves, are formed.

🎯 Exam Tip: Focus on the 'continuous wave action' and 'erosion of cracks and weaknesses in rock' as the main mechanisms for sea cave formation.