ADDITIONAL QUESTIONS AND ANSWERS:
Answer the following questions :
1. Which factors influence the agricultural productivity in terms of the variety of crops grown in our country ?
Ans: The physical features give it an unique climatic regime. The variety in its geology gives rise to various land forms which in turn has given us a variety of minerals, soil and forests. These factors influence the agricultural productivity in terms of the variety of crops grown in our country .
2. Why does one need to study the continental drift theory ?
Ans: The country like India is associated with different physical features like mountains, plains and plateaus. To understand the formation of such features one needs to study the continental drift theory.
3. Name seven major plates and three minor plates present in the tectonic theory .
Ans: The seven major plates are African, North American, South American, Eurasian, Australian, Antarctica and Pacific plates. The minor plates that also exist are the Arabian, Nazca and Philippine plates .
4. What enables the tectonic plates to move ?
Ans: The difference in strength and density between the upper lithosphere and lower asthenosphere enables the tectonic plates to move. Other natural forces like gravity, earth’s rotation also contribute to the movement of the tectonic plates .
5. What is a plate boundary ?
Ans: The plates in relationship with each other move in different directions and at varied speeds. The place where the two plates meet is called a plate boundary .
6. What are the three types of plate boundaries ? Explain each briefly .
Ans:
(i) Convergent Plate Boundaries :
The places where two plates crash or crunch together are called convergent boundaries. These plates move merely a few centimeters from each other .
(ii) Divergent Plate Boundaries :
The places where two plates move apart are called divergent boundaries. As the plates separate along the boundary, the block between the faults crack and fall down. Thereafter, the sinking of the block forms a valley called the rift valley .
(iii) Transform Boundaries :
The places where two plates move past each other are called transform boundaries. The plates on either side of a transform boundary just slide past each other and do not tear each other .
7. What defines India as the northern Indian subcontinent ?
Ans: The great arc of mountains consisting of the Himalayas, Hindu Kush and Patkai ranges defines it as the northern Indian subcontinent .
8. Which factor isolates India from the rest of Asia ?
Ans: The mountain ranges consisting of the Himalayas, Hindu Kush and Patkai have some of the tallest mountains which act as natural barriers to the cold polar winds. It is this factor that isolates India from the rest of Asia .
9. Name the physiographic divisions of India .
Ans: India is divided into the following physiographic divisions :
i) The Northern Mountain ii) The Northern plains
iii) The Peninsular Plateau iv) The Coastal Plains
v) The Indian Deserts vi) The Islands .
10. What is known as the roof of the world ?
Ans: The Pamir plateau with the Pamir Knot in the central Asian country of Tajikistan, is known as the roof of the world .
11. Write a few sentences on the Himalayas .
Ans: The Himalayas are considered to be the highest mountain range in the world and are the youngest fold mountains. The Himalayas are an arc shaped mountain range which extends over a distance of 2500 kms in the North West – South East direction .
12. What are ‘Duns’ and ‘Dwars’ ?
Ans: The wide longitudinal valleys in between the lesser Himalaya and the Shiwaliks are called ‘Duns’ in Western and Central Himalaya and ‘Dwars’ in Eastern Himalaya .
13. What are the regional divisions of the Himalayas ?
Ans: The regional divisions of the Himalayas are Kashmir Himalaya, Himachal and Kumaun Himalayas in the west, Eastern Himalayas and Purvanchal .
14. Write three sentences on each of the following:
(i) Himadri (ii) Himachal (iii) Shivalik .
Ans:
(i) Himadri :
(a) It is the highest Himalayan range .
(b) It is permanently covered with snow .
(c) The world’s tallest mountains are situated in this mountain range, e.g. Kanchenjunga, Nangaparbat .
(ii) Himachal :
(a) It lies to the south of Himadri or greater Himalayas .
(b) Average height is above 3000m .
(c) It has many hill stations like Shimla, Darjeeling .
(iii) Shivalik :
(a) It lies to the south of lesser Himalayas .
(b) These form the foothills of Himalayas .
(c) Several flat valleys run parallel to the mountain ranges. They are referred to as Duns .
15. What is known as the Terai ?
Ans: The numerous smaller streams originating on the slopes of Shivalik disappear in the Bhabar belt. To the south of this belt, they re-appear and create a wet, swampy and marshy region known as the Terai .
16. Agriculture remains the most indispensable occupation in the Ganga plain. Why ?
Ans: The western plain beyond the Ganga is more or less dry. To the east of the Ganga, the soil is very fertile.The rich soil and the abundant water supply and favourable climate make this region good for agriculture. Therefore agriculture remains the most indispensable occupational activity .
17. The great northern plains are densely populated. Why ?
Ans: The rich soil cover combined with the abundant water supply and favourable climate makes this region a highly agriculturally productive section of India. These factors have largely attracted human population thereby making this region the most densely populated region of the country .
18. Write a short note on the Central Highland .
Ans: The Central Highlands cover the area to the north of Narmada river and includes the Malwa Plateau. The Aravalli hills mark its northwest boundary beyond which it merges in the Thar Desert of Rajasthan. The hills of Vindhya outline its southern boundary.The major north flowing rivers are the Chambal, Betwa and the Ken .
19. The Deccan plateau slopes gently eastwards. Why ?
Ans: The Western Ghats are higher than the Eastern Ghats so the Deccan Plateau slopes gently eastwards .
20. What are the different names of the Western ghats in (i) Maharashtra (ii) Tamil Nadu .
Ans: Western Ghats are known as the Sahyadris in Maharashtra and the Niligris in Tamil Nadu .
21. Briefly describe the Eastern Ghats .
Ans: The Eastern Ghats extend from the Mahanadi river valley in the north to the Nilgiris in the south. These hills rise steeply from the Coromandel coastal plain. The Eastern Ghats are well developed in the region between the Godavari and the Mahanadi rivers. The Eastern Ghats are discontinuous as they are intervened by the deltas of the rivers of the Deccan .
22. What is Deccan trap? Explain in brief .
Ans: The Deccan Plateau is covered with a particular black soil called the Deccan Trap. It is also known as the black cotton soil. This soil is rich in humus and ideal for cotton and sugarcane cultivation .
23. How will you describe the Deccan Plateau region ?
Ans: This region is rich in mineral deposits and has many sources for irrigation and generation of hydroelectric power. It is also endowed with a rich and diverse flora and fauna .
24. What forms the coastal plains ?
Ans: The narrow lowlands along the coast of India between the sea and the Eastern and Western Ghats form the coastal plains .
25. How are the Bay of Bengal islands formed ?
Ans: They are formed from the extension of Arakan Yoma mountain and are volcanic in origin .
26. The Bay of Bengal islands are divided into three groups. What are they ?
Ans: They are divided as North Andaman, Middle Andaman and South Andaman .
27. What is Duncan passage ?
Ans: The passage of water separating the Little Andaman from the Great Andaman is known as the Duncan passage .
28. Where are Lakshadweep islands located ?
Ans: At a distance of about 200 to 300 kms off the coast of Kerala lie a group of 25 tiny coral islands in the Arabian Sea known as Lakshadweep .
29. Write a short note on Lakshadweep islands .
Ans: Earlier they were known as Laccadive, Minicoy and Amindivi. They were named Lakshadweep in the year 1973. These islands form the smallest Union Territory of India and have a total land area 32 sq.kms .
The Lakshadweep has nearly thirty-six islands and islets, three reefs and five submerged banks. The main islands are Kavaratti (the capital city), and Minicoy .
30. Name the three physical divisions of Goa. Write a few sentences on each one .
Ans: The three natural physical divisions are the Low lands, the Plateaus and the Mountain region
(i) Low Lands: The low lands are mainly coastal and about 105 km long. Many beaches are located along the coast. It stretches from Terekhol in the north to Polem in the South .
(ii) Plateau Lands: This region comprises of laterite stone which is used for building houses and other construction work. Some parts of the plateau are called headlands .
(iii)Mountain Regions: The Sahyadris part of the Western Ghats are to the east of South Goa. This part is covered with dense forest. In this area, some of the mountains are very steep .
31. What is a headland? Give two examples .
Ans: A headland is a piece of land that projects from the coastline into the sea .
Examples are Sada, Cabo de Ram, Aguada .
32. The mountain region is thickly populated. Why ?
Ans: Many streams and rivers flow from this region to lowlands; making the land fertile and hence it is thickly populated .
33. Distinguish between converging and diverging tectonic plates :
Ans:
| Converging tectonic plates | Diverging tectonic plates |
| 1. When two tectonic plates collide with each other, they are called converging tectonic plates | 1. When tectonic plates move apart from each other, they are called diverging tectonic plates. |
| 2. Here the plates bend downwards and move below One another. | 2. Here the two plates move away from each other. |
34. Distinguish between Bhangar and Khadar .
Ans:
| Bhangar | Khadar |
| 1. The older alluvium of the plain is called Bhangar |
1. The newer, younger deposits of the flood plains are called Khadar. |
| 2. with continuous deposit alluvium, a terrace like feature is formed, which rises above the level of the flood plain. | 2. They are renewed almost every year and so are fertile and ideal for intensive agriculture. |
Fill in the blanks :
1. Bitra is the smallest island in Lakshadweep .
2. The super continent was named as Pangaea and the mega ocean was called Panthalassa .
3. The super continent was broken into two continents that is Eaurasia and Gondwanaland .
4. In the year 1967, Parker and Morgen proposed the tectonic theory.
5. The tectonic plates are composed of two types of lithosphere thicker continental and thin oceanic .
6. The movement of convergent plate boundaries led to the formation of the Himalayas and Great Northern plains .
7. The uninhabited Pitli island has a bird sanctuary .
8. An ancient shallow sea called the Sea of Tethys were on a tectonic plate .
9. The great arc of mountains consisting of Himalayas, Hindu Kush, Patkai ranges defines it as the northern India sub continent .
10. The northern mountain ranges are sub divided into 3 divisions that is TransHimalayas, Himalayas, Purvanchal hills .
11. The plateau is divided into two broad divisions. They are Central Highland and Deccan Plateau .