Major Landforms of Earth
NCERT Exercise Solution
Question 1: How are mountains useful to man?
Answer: Importance of Mountains:
- Mountains are rich sources of water. Many important rivers originate from glaciers on mountains. Water from the mountains is used for irrigation and also for power generation.
- River valleys and terraces are ideal for cultivation.
- Mountains are rich in flora and fauna. The plant species of a place is called flora. The animal species of a place is called fauna.
- Mountains provide many forest produce; like wood, herbs, medicinal plants, honey, catechu, etc.
- Mountains are ideal tourist spots. Many adventure sports are only possible in the mountains; like river rafting, paragliding, hang gliding, skiing, etc.
Question 2: What is the difference between a mountain and a plateau?
|Mountain is narrow at top.||Plateau is flat at top.|
|Mountain’s elevation is in several thousand meters.||Plateau’s elevation is between several hundred and several thousand meters.|
|High mountains are snow-capped.||Most of the plateaus are not covered with snow.|
|Glaciers are found in mountains.||Plateaus do not have glaciers.|
Question 3: What are the major landforms?
Answer: The major landforms are; mountains, plateaus and plains.
Question 4: What are the different types of mountains?
Answer: The different types of mountains are; fold mountains, block mountains and volcanic mountains.
Question 5: How are plains formed?
Answer: Formation of Plains: Plains are usually formed by rivers and their tributaries. When a river flows down a mountain, it erodes the mountain. The river carries forward the eroded material. Then the river deposits the load in its valley. The load consists of stones, sand and silt. Plains are formed from these deposits.
Question 6: Why are the river plains thickly populated?
Answer: Plains are usually highly fertile and hence most ideal for cultivation. It is very easy to make transport network in the plains. Due to above mentioned factors; plains are the best areas for human habitation. Hence, plains are thickly populated.
Question 7: Why are mountains thinly populated?
Answer: Life is difficult in mountain areas because of rugged terrain. Hence, mountain areas are sparsely populated.
Tick the correct answers
Question 1: The mountains differ from the hills in terms of
Answer: (a) elevation
Question 2: Glaciers are found in
- the mountains
- the plains
- the plateaus
Answer: (a) the mountains
Question 3: The Deccan Plateau is located in
Answer: (c) India
Question 4: The river Yangtze flows in
- South America
Answer: (c) China
Question 5: An important mountain range of Europe is
- the Andes
- the Alps
- the Rockies
Answer: (b) the Alps
Fill in the blanks:
- A ___________ is an unbroken flat or a low-level land.
- The Himalayas and the Alps are examples of _______________types of mountains.
- _____________ areas are rich in mineral deposits.
- The _________________ is a line of mountains.
Answer: mountain range
- The ____________areas are most productive for farming.
Question 1: What is a mountain?
Answer: A mountain is the natural elevation of the earth’s surface. A mountain may be narrow at top and broad at the base. The elevation of mountain is considerably more than that of surrounding area.
Question 2: What is a plateau?
Answer: A plateau is a flat and elevated land. A plateau is at higher elevation than the surrounding areas. A plateau may have one or more sides with steep slopes.
Question 3: What is a plain?
Answer: Plains are flat lands and are generally not more than 200 m above mean sea level. Some plains are extremely level, while others may be slightly rolling and undulating.
Question 4: Describe the formation of fold mountains.
Answer: When a tectonic plate gets pressure from two sides, it gets folded. Some of its portion becomes elevated and forms the mountains. The depressions form the valleys.
Question 5: Describe the formation of block mountains.
Answer: When large areas are broken and displaced vertically, Block Mountains are formed. In this case, the uplifted blocks are called horsts. On the other hand, the lowered blocks are called graben.
Question 6: What is the significance of plateaus?
Answer: Importance of Plateau
- Plateaus are rich in mineral deposits. Many mining belts in the world are located in the plateau areas.
- Most of the mining areas in India are in the Chhotanagpur Plateau in Jharkhand, Orissa and Chhattisgarh.
- The African plateau is famous for mines of gold and diamond.
- Many waterfalls are present in plateau areas. For example; the Hundru falls in the Chhotanagpur and Jog falls in Karnataka.
- The lava plateaus are rich in black soil. Black soil is fertile and is good for cultivation.
- Plateau areas are great tourist attractions because of lot of scenic spots.
Question 7: Discuss the processes which lead to formation of landforms.
Answer: There are two processes which lead to formation of different landforms. These processes are; internal process and external process.
Internal Process: The earth beneath your feet is continuously moving. The movement of earth’s surface results in internal process. The internal process results in a portion of the earth’s surface getting elevated or getting sunk.
External Process: Continuous wearing down and rebuilding of the earth’s surface is the result of external process.