Ratna Sagar Geography Solutions Solutions for Class 6 Social science Chapter 6 - Major Landforms Of The Earth

Answer:

The correct answer is option (d).

Explanation: The main agents of erosion and deposition are winds, running water, glaciers and sea waves. Volcanoes are not an agent of erosion and deposition. 

Answer:

The correct answer is option (c).

Explanation: The Prairies are not mountains. They are grasslands of the North American continent. The Rockies are a mountain range of North America, the Andes are a mountain range of South America and the Apennines are a mountain range of Europe.

Answer:

The correct answer is option (a).

Explanation: The Himalayas and the Rockies are of recent origin. Hence, they are called young fold mountains. The Aravallis, on the other hand, are comparatively old, so they are called old fold mountains. But Kilimanjaro does not fit into either category; it was formed by a volcanic eruption.

Answer:

The correct answer is option (c).

Explanation: Cotopaxi in South America, Fujiyama in Japan and Rainier in the USA are mountains of volcanic origin. These mountains are formed by the solidification of lava erupted from volcanos. Karakoram is a part of the Himalayan mountain system formed by folding.

Answer:

The correct answer is option (d).

Explanation: Plateaus are the land masses that rise abruptly from the neighbouring areas with steep slopes. Their top is either rounded or flat. Owing to their large area, they are also known as tablelands.

Answer:

The correct answer is option (b).

Explanation: Among the given alternatives, the Columbian Plateau in the USA, the Bolivian Plateau in the Andes and the Bie Plateau in South Africa are categorised as plateaus. The Pampas, on the other hand, are the grasslands of South America.

 

Answer:

The correct answer is option (a).

Explanation: The Tibetan Plateau is the highest plateau in the world. It covers the area around Central Asia and the north of the Himalayas. It is approximately 4,500 metres high.

Answer:

The correct answer is option (a).

Explanation: Plains are flat and low-lying areas. Since they are formed by the deposition of sand and silt brought by rivers, they are very fertile. This is the reason farming is the main occupation of the people living in these areas.

Answer:

1. The forces which originate from within the earth are called tectonic forces.

Explanation: Tectonic forces originate from within the Earth's surface. They cause irregularities on the surface of the Earth, thereby forming highlands and lowlands.

2. â€‹The wearing away of the earth's surface is called erosion.

Explanation: Erosion is the phenomenon of the removal of the top layer of the Earth's surface through the action of agents like air, running water and glaciers.

3. â€‹A mountain chain has several parallel, long and narrow ranges.

Explanation: In a mountain chain, there are numerous long mountain ranges running parallel to each other. For example, the Himalayan mountain chain is divided into the higher, middle and lower Himalayas.
 
4. â€‹Big cities are located in the plains.

Explanation: Plains are wide stretches of land at a relatively low height. They are the fertile lands formed by the deposition of sand and silt brought by rivers. Hence, they are densely populated. This is the reason big cities are located in plains.

Answer:

1. The examples of fold mountains are given below.

• The Himalayas in Asia
• The Rockies in North America

• The Black Forest in Germany
• The Salt Range in Pakistan

• Mount Vesuvius in Italy
• Mount Kilimanjaro in Africa

• The Plateau of Bolivia in the Andes
• The Tibetan Plateau in Asia

• The Ranchi Plateau in India
• The Potwar Plateau in Pakistan

• The Columbian Plateau in the USA
• The Malwa Plateau in India

Answer:

1. The given statement is true.

Explanation: Tectonic forces originate within the Earth's surface. They cause irregularities on the surface of the Earth, thereby forming highlands and lowlands.

2. â€‹The given statement is false.

Explanation: Cordillera is a Spanish term that stands for several mountain systems. They stretch over a large area of a continent.

3. â€‹The given statement is false.

Explanation: Plateaus are land masses that rise abruptly from the neighbouring areas with steep slopes. Their top is either rounded or flat. They are the oldest landforms on the Earth.

4. â€‹The given statement is true.

Explanation: Plains are wide stretches of land at relatively low height. They are fertile lands formed by the deposition of sand and silt brought by rivers. River valleys were the cradles of civilisation in ancient times.

Answer:

1. 

Answer:

1. Fold mountains: These mountains are formed by the folding of tectonic layers within the Earth's surface. They are of two types: young fold mountains and old fold mountains. The Himalayas and the Rockies are of recent origin; hence, they are called young fold mountains. The Aravallis, on the other hand, are comparatively old, so they are called old fold mountains.

2. Block mountains: The horizontal movement of plates results into cracks and faults on the Earth's surface. With the breaking of these faults, blocks emerge. When they rise to a high elevation, they are referred to as block mountains. They have steep slopes and flat tops. One example is the Black Forest in Germany.

3. Volcanic mountains: These mountains are formed as a result of the solidification of the lava that comes of the volcanos and gets accumulated near their mouth. Cotopaxi in South America, Fujiyama in Japan and Rainier in the USA are the mountains of volcanic origin.

4. Intermontane plateaus: These are the plateaus that are enclosed between high mountains. They are very high and complex structures of the Earth. For example, the Tibetan Plateau is the highest plateau in the world. It is bounded by the Himalayas and covers a large part of Asia and Central Asia.

5. Continental plateaus: The plateaus that rise abruptly from either seas or lowlands are referred to as continental plateaus. The Potwar Plateau in Pakistan and the Ranchi Plateau in India are continental plateaus. 

6. Plains: They are the lowlands formed by the deposition of silt caused by the running water of rivers. The silt and sand brought by the rivers get deposited and result into the formation of plains. These areas are generally very fertile; hence, they are densely populated, for example, the Northern Plains of India.

Answer:

1. Fold mountain in North America - The Rockies

2. â€‹Block mountain in Europe - The Black Forest in Germany  

3. â€‹Volcanic mountain in Indonesia - Krakatao

4. â€‹Highest plateau in the world - The Tibetan Plateau in Asia
 
5. â€‹Lava plateau in India - The Deccan and Malwa Plateau
 
6. Plains of Argentina - The Pampas

Answer:

On the basis of origin, mountains can be classified into the following three categories:

1. Fold mountains: These mountains are formed by the folding of tectonic layers within the Earth's surface. They are of two types: young fold mountains and old fold mountains. The Himalayas and the Rockies are of recent origin; hence, they are known as young fold mountains. The Aravallis, on the other hand, are comparatively old, so they are called old fold mountains.

2. Block mountains: The horizontal movement of plates results into cracks and faults on the Earth's surface. With the breaking of these faults, blocks emerge. When they rise to a high elevation, they are referred to as block mountains. They have steep slopes and flat tops. One example is the Black Forest in Germany.

3. Volcanic mountains: These mountains are formed as a result of the solidification of the lava that is vented out of volcanos and gets accumulated near their mouth. Cotopaxi in South America, Fujiyama in Japan and Rainier in the USA are the mountains of volcanic origin.

Answer:

There occurs continuous movements within the surface of the Earth. These movements are caused by tectonic forces. They originate within the Earth's surface and cause irregularities on the surface of the Earth. They result in the subsidence of the surface. The gradational forces modify these irregularities to form several landforms like mountains, plateaus and plains. Volcanic mountains are formed by the solidification of the lava near the vents of volcanos. 

Answer:

Mountains are useful to us in the following ways:

• They cause winds to rise, causing the condensation of moisture.
• They are effective barriers against the hot and cold winds. For example, the Himalayas protect the Indian mainland from cold Siberian winds.
• The slopes of mountains have a rich variety of forests and grasslands.
• Mountains are a major source of origin of rivers, which provide water for irrigation.
• They are important tourist destinations during summers.
• They are a storehouse of several minerals.
• The rock material found in mountains is used in construction.

Answer:

The difference between mountains and plateaus can be understood with the help of the table given below.
 

Answer:

Plains are found in low-lying areas that barely have any difference between their highest and lowest points. They are generally formed by the phenomena of erosion and deposition caused by the running water of rivers. The silt and alluvium brought by the rivers result in fertile soil, which, in turn, promotes agriculture in these areas. As a result, agriculture is the prime occupation of people living in plains. Due to this, these plains are densely populated. It also results in the growth of the service sector that aims to provide good facilities to the people residing in these areas. 

Answer:

Mountainous regions are sparsely populated because of the following reasons:

• Life is very difficult in terrain.
• ​The uneven topography makes it very difficult to build basic infrastructure, which includes roads and houses.
• Facilities like hospitals, schools and banks are inaccessible to the people living in these areas.
• The extreme low temperature too proves hostile for a easy and comfortable life.  Combined with topography, it is a barrier to large scale agriculture.

Answer:

River valleys are thickly populated because of the following reasons:

• Rivers provide water, which is essential for several household and industrial purposes.
• The silt brought by rivers results in the formation of alluvial soil, which is very fertile.
• Farming is the major occupation of people living in these areas.
• River valleys are easily accessible. Therefore, people prefer to live in plains.

Answer:

Life in mountainous regions is very difficult owing to the below-mentioned reasons:

• The uneven topography makes it difficult to build proper infrastructure in the form of roads, hospitals, schools, etc.
• Access to these regions is very difficult and very risky too.
• Generally, the temperature in these regions is very low; this makes it difficult for the people to stay there.
• The land available for cultivation is very less. Hence, people are dependent on plains for their needs.
• The hilly areas are far-flung; hence, the development in these areas is slow.