Selina Textbook Solutions: Landforms of the Earth | Geography Class 9 ICSE PDF Download

 Page 1


Landforms of the Earth 
Exercises 
I. Short answer questions. 
Question 1. 
What is meant by a landform ? 
Answer: 
A landform is a natural feature on the surface of the earth with a particular shape. 
Question 2. 
Why are the fold mountains called so ? 
Answer: 
Fold mountains are called so because of the result of large- scale earth movements 
caused by stresses in the earth’s crust. Such stresses may be caused by weight of the 
overlying rocks, movements in the mantle, the expansion or contraction of some part of 
the earth, etc. These stresses subject the rocks to compressive forces, producing 
wrinkling or folding along the lines of weakness. This is shown in fig. the raising of folds 
makes the fold mountains. 
 
Question 3. 
Give two chief characteristics of the fold mountains. 
Answer: 
1. The fold mountain system has parallel ranges. 
2. A fold mountain region is also a region of sudden forces such as of volcanoes and 
earthquakes. 
Question 4. 
Give one example of each : 
(a) Young fold mountains; 
(b) Old fold mountain. Why they are called so 
 
Page 2


Landforms of the Earth 
Exercises 
I. Short answer questions. 
Question 1. 
What is meant by a landform ? 
Answer: 
A landform is a natural feature on the surface of the earth with a particular shape. 
Question 2. 
Why are the fold mountains called so ? 
Answer: 
Fold mountains are called so because of the result of large- scale earth movements 
caused by stresses in the earth’s crust. Such stresses may be caused by weight of the 
overlying rocks, movements in the mantle, the expansion or contraction of some part of 
the earth, etc. These stresses subject the rocks to compressive forces, producing 
wrinkling or folding along the lines of weakness. This is shown in fig. the raising of folds 
makes the fold mountains. 
 
Question 3. 
Give two chief characteristics of the fold mountains. 
Answer: 
1. The fold mountain system has parallel ranges. 
2. A fold mountain region is also a region of sudden forces such as of volcanoes and 
earthquakes. 
Question 4. 
Give one example of each : 
(a) Young fold mountains; 
(b) Old fold mountain. Why they are called so 
 
Answer: 
(a) These mountains are made of light sedimentary rocks of recent tertiary age and are 
the highest mountain system which are still increasing their heights due to gradual 
upthrust force. The Himalayas are called young fold mountains. 
(b) The Alpine-Himalayan system and Circum Parific mountain belt are the ‘Old Fold 
Mountains’ which existed as geosynclines 50-60 million years ago. 
Question 5. 
Give example of residual mountains. 
Answer: 
Examples of Residual mountains are Nilgiri, Parasnath and Rajmahal Hills in India and 
the Catskill range in the USA. 
Question 6. 
How is a rift valley formed ? Give one example of a rift valley. 
Answer: 
A rift valley is formed by the submergence of a big landmass between two high block 
mountains, e.g. the Rhine river flows through a rift valley in its middle course. 
Question 7. 
Give a brief definition of a plateau. 
Answer: 
The Himalayas are an important form of folding being the highest mountain range in the 
world. 
Question 8. 
Give one example of each : 
(a) Intermontane plateau 
(b) Volcanic plateau and 
(c) Piedmont plateau 
Answer: 
(a) The Tibetan plateau 
(b) The Plateau of Peninsular India. 
(c) The Patagonian plateau of South America. 
Question 9. 
Give two points of importance of landforms. 
Answer: 
Various landforms display the internal and external forces of the earth, different climatic 
Page 3


Landforms of the Earth 
Exercises 
I. Short answer questions. 
Question 1. 
What is meant by a landform ? 
Answer: 
A landform is a natural feature on the surface of the earth with a particular shape. 
Question 2. 
Why are the fold mountains called so ? 
Answer: 
Fold mountains are called so because of the result of large- scale earth movements 
caused by stresses in the earth’s crust. Such stresses may be caused by weight of the 
overlying rocks, movements in the mantle, the expansion or contraction of some part of 
the earth, etc. These stresses subject the rocks to compressive forces, producing 
wrinkling or folding along the lines of weakness. This is shown in fig. the raising of folds 
makes the fold mountains. 
 
Question 3. 
Give two chief characteristics of the fold mountains. 
Answer: 
1. The fold mountain system has parallel ranges. 
2. A fold mountain region is also a region of sudden forces such as of volcanoes and 
earthquakes. 
Question 4. 
Give one example of each : 
(a) Young fold mountains; 
(b) Old fold mountain. Why they are called so 
 
Answer: 
(a) These mountains are made of light sedimentary rocks of recent tertiary age and are 
the highest mountain system which are still increasing their heights due to gradual 
upthrust force. The Himalayas are called young fold mountains. 
(b) The Alpine-Himalayan system and Circum Parific mountain belt are the ‘Old Fold 
Mountains’ which existed as geosynclines 50-60 million years ago. 
Question 5. 
Give example of residual mountains. 
Answer: 
Examples of Residual mountains are Nilgiri, Parasnath and Rajmahal Hills in India and 
the Catskill range in the USA. 
Question 6. 
How is a rift valley formed ? Give one example of a rift valley. 
Answer: 
A rift valley is formed by the submergence of a big landmass between two high block 
mountains, e.g. the Rhine river flows through a rift valley in its middle course. 
Question 7. 
Give a brief definition of a plateau. 
Answer: 
The Himalayas are an important form of folding being the highest mountain range in the 
world. 
Question 8. 
Give one example of each : 
(a) Intermontane plateau 
(b) Volcanic plateau and 
(c) Piedmont plateau 
Answer: 
(a) The Tibetan plateau 
(b) The Plateau of Peninsular India. 
(c) The Patagonian plateau of South America. 
Question 9. 
Give two points of importance of landforms. 
Answer: 
Various landforms display the internal and external forces of the earth, different climatic 
effects and features, forests, snow lands giving birth to rivers, coasts and islands as 
fishing regions. All these together make the earth beautiful and ideal for living and 
various activities. 
Question 10. 
What are known as epeirogenic movements ? 
Answer: 
The movements such as uplift and submergence working in vertical direction are known 
as epeirogenic movements. ‘Epeiros’ in Greek means continent ‘genic’ means building. 
As this movement created continents coming out higher from the oceans. 
Question 11. 
Name two landforms created by epeirogenic movements. 
Answer: 
1. Block mountains. 
2. Rift valleys and basins are produced by epeirogenic movements. 
Question 12. 
Why are the sudden forces described as ‘Constructive forces ? 
Answer: 
Earthquakes and volcanic activities are described as sudden forces. These forces are 
described as ‘Constructive Forces’ because they create relief features on the surface of 
the earth. As volcanic erruptions result in the formation of volcanic mountains, extensive 
plateaus and also plains. 
Question 13. 
What are called endogenic forces ? 
Answer: 
Endogenic forces are the internal diastrophic forces working inside the interior of the 
earth related to the tectonic forces. 
Question 14. 
Name four relief features on the surface of the earth. 
Answer: 
The four major landforms are mountains, plateaus, plains, valleys and basins. 
Question 15. 
What are known as exogenic forces ? 
Answer: 
Exogenic forces work on the surface of the earth through water, wind and ice, resulting 
in changing the shape of landforms slowly. 
Page 4


Landforms of the Earth 
Exercises 
I. Short answer questions. 
Question 1. 
What is meant by a landform ? 
Answer: 
A landform is a natural feature on the surface of the earth with a particular shape. 
Question 2. 
Why are the fold mountains called so ? 
Answer: 
Fold mountains are called so because of the result of large- scale earth movements 
caused by stresses in the earth’s crust. Such stresses may be caused by weight of the 
overlying rocks, movements in the mantle, the expansion or contraction of some part of 
the earth, etc. These stresses subject the rocks to compressive forces, producing 
wrinkling or folding along the lines of weakness. This is shown in fig. the raising of folds 
makes the fold mountains. 
 
Question 3. 
Give two chief characteristics of the fold mountains. 
Answer: 
1. The fold mountain system has parallel ranges. 
2. A fold mountain region is also a region of sudden forces such as of volcanoes and 
earthquakes. 
Question 4. 
Give one example of each : 
(a) Young fold mountains; 
(b) Old fold mountain. Why they are called so 
 
Answer: 
(a) These mountains are made of light sedimentary rocks of recent tertiary age and are 
the highest mountain system which are still increasing their heights due to gradual 
upthrust force. The Himalayas are called young fold mountains. 
(b) The Alpine-Himalayan system and Circum Parific mountain belt are the ‘Old Fold 
Mountains’ which existed as geosynclines 50-60 million years ago. 
Question 5. 
Give example of residual mountains. 
Answer: 
Examples of Residual mountains are Nilgiri, Parasnath and Rajmahal Hills in India and 
the Catskill range in the USA. 
Question 6. 
How is a rift valley formed ? Give one example of a rift valley. 
Answer: 
A rift valley is formed by the submergence of a big landmass between two high block 
mountains, e.g. the Rhine river flows through a rift valley in its middle course. 
Question 7. 
Give a brief definition of a plateau. 
Answer: 
The Himalayas are an important form of folding being the highest mountain range in the 
world. 
Question 8. 
Give one example of each : 
(a) Intermontane plateau 
(b) Volcanic plateau and 
(c) Piedmont plateau 
Answer: 
(a) The Tibetan plateau 
(b) The Plateau of Peninsular India. 
(c) The Patagonian plateau of South America. 
Question 9. 
Give two points of importance of landforms. 
Answer: 
Various landforms display the internal and external forces of the earth, different climatic 
effects and features, forests, snow lands giving birth to rivers, coasts and islands as 
fishing regions. All these together make the earth beautiful and ideal for living and 
various activities. 
Question 10. 
What are known as epeirogenic movements ? 
Answer: 
The movements such as uplift and submergence working in vertical direction are known 
as epeirogenic movements. ‘Epeiros’ in Greek means continent ‘genic’ means building. 
As this movement created continents coming out higher from the oceans. 
Question 11. 
Name two landforms created by epeirogenic movements. 
Answer: 
1. Block mountains. 
2. Rift valleys and basins are produced by epeirogenic movements. 
Question 12. 
Why are the sudden forces described as ‘Constructive forces ? 
Answer: 
Earthquakes and volcanic activities are described as sudden forces. These forces are 
described as ‘Constructive Forces’ because they create relief features on the surface of 
the earth. As volcanic erruptions result in the formation of volcanic mountains, extensive 
plateaus and also plains. 
Question 13. 
What are called endogenic forces ? 
Answer: 
Endogenic forces are the internal diastrophic forces working inside the interior of the 
earth related to the tectonic forces. 
Question 14. 
Name four relief features on the surface of the earth. 
Answer: 
The four major landforms are mountains, plateaus, plains, valleys and basins. 
Question 15. 
What are known as exogenic forces ? 
Answer: 
Exogenic forces work on the surface of the earth through water, wind and ice, resulting 
in changing the shape of landforms slowly. 
Question 16. 
Name the two land forms produced by exogenic forces. 
Answer: 
1. Alluvial and erosional plains 
2. Glacial landforms. 
Question 17. 
Give one chief characteristic of the fold mountains. 
Answer: 
The fold mountains are formed by the lateral compression of sedimentary rocks as seen 
by the different layers of various types of rocks one upon another. 
Question 18. 
Give one example of volcanic mountains. 
Answer: 
Volcanic mountains are formed by erupting magma from the inner core on the surface 
e.g. Mt. Krakatoa is an active volcano on the western side of Java. 
Question 19. 
How is a rift valley formed ? Give one example. 
Answer: 
A rift valley is formed by the submergence of a big landmass between two high block 
mountains, e.g. the Rhine river flows through a rift valley in its middle course. 
Question 20. 
Give a brief definition of a plateau. 
Answer: 
A plateau is a higher tableland between mountain and valley, lower than mountain and 
higher than valley. 
Question 21. 
Give one example of each 
(a) Intermontane plateau 
(b) Piedmont plateau 
(c) Volcanic plateau. 
Answer: 
(a) The Tibetan plateau. 
(b) The Patagonian plateau of South America. 
(c) The Plateau of Peninsular India. 
Page 5


Landforms of the Earth 
Exercises 
I. Short answer questions. 
Question 1. 
What is meant by a landform ? 
Answer: 
A landform is a natural feature on the surface of the earth with a particular shape. 
Question 2. 
Why are the fold mountains called so ? 
Answer: 
Fold mountains are called so because of the result of large- scale earth movements 
caused by stresses in the earth’s crust. Such stresses may be caused by weight of the 
overlying rocks, movements in the mantle, the expansion or contraction of some part of 
the earth, etc. These stresses subject the rocks to compressive forces, producing 
wrinkling or folding along the lines of weakness. This is shown in fig. the raising of folds 
makes the fold mountains. 
 
Question 3. 
Give two chief characteristics of the fold mountains. 
Answer: 
1. The fold mountain system has parallel ranges. 
2. A fold mountain region is also a region of sudden forces such as of volcanoes and 
earthquakes. 
Question 4. 
Give one example of each : 
(a) Young fold mountains; 
(b) Old fold mountain. Why they are called so 
 
Answer: 
(a) These mountains are made of light sedimentary rocks of recent tertiary age and are 
the highest mountain system which are still increasing their heights due to gradual 
upthrust force. The Himalayas are called young fold mountains. 
(b) The Alpine-Himalayan system and Circum Parific mountain belt are the ‘Old Fold 
Mountains’ which existed as geosynclines 50-60 million years ago. 
Question 5. 
Give example of residual mountains. 
Answer: 
Examples of Residual mountains are Nilgiri, Parasnath and Rajmahal Hills in India and 
the Catskill range in the USA. 
Question 6. 
How is a rift valley formed ? Give one example of a rift valley. 
Answer: 
A rift valley is formed by the submergence of a big landmass between two high block 
mountains, e.g. the Rhine river flows through a rift valley in its middle course. 
Question 7. 
Give a brief definition of a plateau. 
Answer: 
The Himalayas are an important form of folding being the highest mountain range in the 
world. 
Question 8. 
Give one example of each : 
(a) Intermontane plateau 
(b) Volcanic plateau and 
(c) Piedmont plateau 
Answer: 
(a) The Tibetan plateau 
(b) The Plateau of Peninsular India. 
(c) The Patagonian plateau of South America. 
Question 9. 
Give two points of importance of landforms. 
Answer: 
Various landforms display the internal and external forces of the earth, different climatic 
effects and features, forests, snow lands giving birth to rivers, coasts and islands as 
fishing regions. All these together make the earth beautiful and ideal for living and 
various activities. 
Question 10. 
What are known as epeirogenic movements ? 
Answer: 
The movements such as uplift and submergence working in vertical direction are known 
as epeirogenic movements. ‘Epeiros’ in Greek means continent ‘genic’ means building. 
As this movement created continents coming out higher from the oceans. 
Question 11. 
Name two landforms created by epeirogenic movements. 
Answer: 
1. Block mountains. 
2. Rift valleys and basins are produced by epeirogenic movements. 
Question 12. 
Why are the sudden forces described as ‘Constructive forces ? 
Answer: 
Earthquakes and volcanic activities are described as sudden forces. These forces are 
described as ‘Constructive Forces’ because they create relief features on the surface of 
the earth. As volcanic erruptions result in the formation of volcanic mountains, extensive 
plateaus and also plains. 
Question 13. 
What are called endogenic forces ? 
Answer: 
Endogenic forces are the internal diastrophic forces working inside the interior of the 
earth related to the tectonic forces. 
Question 14. 
Name four relief features on the surface of the earth. 
Answer: 
The four major landforms are mountains, plateaus, plains, valleys and basins. 
Question 15. 
What are known as exogenic forces ? 
Answer: 
Exogenic forces work on the surface of the earth through water, wind and ice, resulting 
in changing the shape of landforms slowly. 
Question 16. 
Name the two land forms produced by exogenic forces. 
Answer: 
1. Alluvial and erosional plains 
2. Glacial landforms. 
Question 17. 
Give one chief characteristic of the fold mountains. 
Answer: 
The fold mountains are formed by the lateral compression of sedimentary rocks as seen 
by the different layers of various types of rocks one upon another. 
Question 18. 
Give one example of volcanic mountains. 
Answer: 
Volcanic mountains are formed by erupting magma from the inner core on the surface 
e.g. Mt. Krakatoa is an active volcano on the western side of Java. 
Question 19. 
How is a rift valley formed ? Give one example. 
Answer: 
A rift valley is formed by the submergence of a big landmass between two high block 
mountains, e.g. the Rhine river flows through a rift valley in its middle course. 
Question 20. 
Give a brief definition of a plateau. 
Answer: 
A plateau is a higher tableland between mountain and valley, lower than mountain and 
higher than valley. 
Question 21. 
Give one example of each 
(a) Intermontane plateau 
(b) Piedmont plateau 
(c) Volcanic plateau. 
Answer: 
(a) The Tibetan plateau. 
(b) The Patagonian plateau of South America. 
(c) The Plateau of Peninsular India. 
Question 22. 
How are erosional plains formed ? 
Answer: 
Erosional plains are formed by the agents of erosion in millions of years, when the 
higher landforms are eroded into level plain areas, e.g. Lorraine plain in France. 
Question 23. 
Give two points of importance of landforms. 
Answer: 
Various landforms display the internal and external forces of the earth, different climatic 
effects and features, forests, snow lands giving birth to rivers, coasts and islands as 
fishing regions. All these together make the earth beautiful and ideal for living and 
various activities. 
II. Distinguish between each of the following  
1. Fold Mountain and Block Mountain. 
2. Intermontane plateau and Volcanic plateau. 
3. Structural plain and Depositional plains. 
4. Tectonic mountain and Volcanic mountain. 
Answer: 
1. Fold Mountain : 
1. Fold mountains is built by the tectonic forces folding the sedimentary rocks. 
2. These are formed of light sedimentary rocks e.g. the Himalayas 
Block Mountain : 
1. Block mountain is built after the submergence of a landmass leaving behind the 
big blocks on the both sides. 
2. These are formed by solid rocks standing on the both sides of a rift valley. e.g. 
Vosges mountain in France. 
2. Intermontane plateau : These are the highest and most extensive types on the 
globe surrounded by hills and mountains. The plateau of Tibet is the highest plateau as 
well as most extensive intermontane plateau. Other examples are Columbian Plateau, 
North Americal Cordillera, Bolivian, Peruvian and Mexican plateaus. 
Volcanic Plateau : In places where fissure eruptions have taken place magma erupts 
quietly through narrow fissures several kilometres in length. This magma spreads on the 
surface and cools down as a sheet of lava covering the surface of the land. Eruptions at 
intervals lead to the piling up of lava sheets one over the other in a series of steps. The 
Deccan trap region of Peninsular India has several lava sheets having a maximum