Q.1. What is Plate Tectonics?
Ans. The concept of Plate Tectonics, developed in 1960s explains the origin of continents, oceans and other landforms. Plate is a broad segment of lithosphere that floats on asthenosphere continuously. The concept explains the movement of the crustal plate.
Q.2. What is the peninsular plateau composed of?
Ans. Igneous and metamorphic rocks.
Q.3. What are the longitudinal division of Himalayas?
Ans. a. Himadri b. Himachal c. Shiwaliks
Q.4. How are the Himalayas divided regionally or on the basis of river valleys?
Ans. a. Punjab Himalayas between river Indus and Satluj b. Kumaon Himalayas between river Satluj and Kali c. Nepal Himalayas between river Kali and Teesta d . Assam Himalayas between river Teesta and Brahmaputra.
Q.5. What are distributaries?
Ans. Distributaries are the numerous channels which get split from the main river when it is about to enter the sea.
Q.6. Identify the regional division of the Northern Plains.
Ans. a. Punjab Plains b. Ganga Plain c. Brahmaputra Plain
Q.7. What are the relief features that are found in the Northern Plains?
Ans. a. Bhabar b. Terai c. Bhangar d. Khadar
Q.8. Which landform feature was a part of Gondwanaland?
Ans. Peninsular plateau
Q.9. Which plateau lies between the Aravallies and the Vindhaya range?
Ans. Malwa plateau
Q.10. Where is the Aravali hills located?
Ans. The Aravali hills lie on the western and north-western margins of the peninsular plateau in Rajasthan.
Q.11. Name the landmasses that were included in the Gondwanaland.
Ans. India, Australia, Southern Africa, South America
Q.12. What is a doab?
Ans. The land between two rivers is known as a doab. ‘Do’ means two and ‘ab’ means water.
Q.13. What are riverine islands?
Ans. In the lower course of the river, due to gentle slope, the velocity of the river decreases and it involves into depositional work leading to the formation of riverine islands. Ex. Majuli in Brahmaputra
Q.14. Which island in Lakshadweep has got a bird sanctuary? ‘
Ans. Pitli island
Q.15. Differentiate between Convergent and Divergent Plate Boundaries.
Ans. CONVERGENT PLATE BOUNDARIES DIVERGENT PLATE BOUNDARIES ( Put it in a tabular column)
i.The tectonic plates move closer to each-other in convergent plate boundaries.
i. Tectonic plates move away from each-other in divergent plate boundaries
ii. The two plates coming together may either collide, or may slide under the other.
ii. The two plates drift away from each-other creating gap between the two.
iii. Convergence of plates may result into activities like earthquake.
iii. Divergence of plates may result into volcanic eruption.
iv. Formation of Himalayas is a result of convergence of plates.
iv. Formation of Great Atlantic drift is a result of divergence of plates.
Q.16. How was the Himalayas formed?
Ans. a. Himalayas are the product of a process of the convergence of Indo-Australian plate and Eurasian plate.
- Some 70 million years ago, the Indian plate started moving towards the Eurasian plate and the Tethys Sea between the two began to contract due to this movement.
- There occurred the lateral compression of the marine sediments in the bed of the Tethys Sea.
- Geologists believe that the sediments got folded giving rise to the ranges of Himalayas.
Q.17. What is the shape and size of the Himalayas?
Ans. a. Himalayas run in a west –east direction from Indus to Brahmaputra covering 2400km. b. They form an arc.
- Width of the Himalayas varies from 400km in Kashmir to 150 km in Arunachal Pradesh.
- Average height of the Himalayas also varies from about 6000m to 900m above the sea level.
Q.18. “Himalayas are the young fold mountains.” Justify the given statement.
Ans. A. Himalayas were formed as result of convergence of plates that further resulted into the folding of sediments from the Tethys Sea. Therefore, they are Fold Mountains.
- Himalayas have conical peaks and deep valleys which indicate that Himalayas are still young.
- Geologists believe that the Height of the Himalayas is still rising.
- Himalayas are 7 million years old. This time period is considered as very young in the geological time scale. Therefore, we can say that the Himalayas are “Young Fold Mountains.”
Q.19. Write the characteristics of the following:
Ans. I. HIMADRI It is the northernmost range of Himalayas. Also known as “Great Himalayas” or “Inner Himalayas”. It is the most continuous range consisting of very high peaks.
Average height of Himadri range is 6000m Core of the Himadri range is composed of granite. It is covered with snow almost throughout the year and a number of glaciers descend from it.
- HIMACHAL This range lies to the south of Himadri and forms the most rugged mountain system. Also known as “Lesser Himalayas”. It is mainly composed of highly compressed and altered rocks. Altitude varies between 3700 to 4500m and average width is 50m. Further divided into – Pir Panjal range, Mahabharata and Dhauladhar range. Well known for hill stations- Kashmir valley, Kullu valley, Kangra valley.
III. SHIWALIKS It is the outermost range of Himalayas. Width extends over 10-50km and altitude 900-1100m. Composed of unconsolidated sediments brought down by rivers. Covered with thick gravel and alluvium. Longitudinal valleys between Himachal and Shiwaliks are found known as ‘Duns’. Ex.- Dehradun, Patlidun, Kotlidun.
- PURVANCHALS Beyond the Dihang gorge, Himalayas bend sharply to the south and spread along the eastern boundary of India known as Purvanchals or Eastern hills. They are mostly composed of strong sandstones which are sedimentary rocks. Forms a natural frontier between India and Myanmar. Covered with dense forest and mostly run as parallel range. It is comprised of Patkai hills, Naga hills, Manipur hills, and Mizo hills.
Q.20. How was the Northern Plains formed?
Ans. 1. After the formation of the Himalayas out of the Tethys sea, the vast basin was formed at the foothills of the Himalayas.
- Thereafter, the deposition of alluvium in the vast basin was done for the millions of years.
- This deposition was done mainly by the three river systems – Indus, Ganga, and Brahmaputra that resulted into the formation of Northern Plains.
Q.21. Why the Northern Plains are most densely populated areas of the world?
Ans. A. FLAT TERRAIN The Northern Plain region has got flat topography almost without any undulations making it easier for the human beings to construct houses, industries, transport and to do agriculture.
- ADEQUATE CLIMATE The Northern Plains experience almost every type of climate giving a wide variety of doing agriculture.
- FERTILE SOIL The soil present here is highly fertile because of the sedimentation done by the rivers making it suitable for agriculture.
- RIVER SUPPLY Many rivers and tributaries are present here providing regular supply of water for agriculture, industries and other domestic works. Therefore, Northern Plains are densely populated regions of the world.
Q.22. Differentiate between the following:
Ans. BHABAR AND TERAI ( Put it in a tabular column)
i. It lies to the south of Shiwalik range.
i. The belt exist to the south of Bhabar area.
ii. The width ranges between 8 to 16km.
ii. It is almost parallel to the Bhabar.
iii. The area is highly coarse in nature due to many pebbles and ‘kankars’ found over here.
iii. The area has got highly fine sediments due to the deposition made by several streams.
iv. Main feature is that river disappear in the Bhabar region because if big pores present in it.
iv. Since the river re-emerges back in this region, the area becomes highly swampy and marshy.
v. Vegetation found here is very less.
v. Very dense vegetation is found in Terai region.
KHADAR and BHANGAR ( Put it in a tabular column)
i. Khadar is the new alluvium that is formed after the recent deposition made by the river.
i. Bhangar is the old alluvium that is formed after the change in the course of the river.
ii. Being new, khaddar is more fertile.
ii. Since bhangar has been used up, therefore, the fertility is comparatively less.
iii. Soil is very fine in nature.
iii. The texture of the soil is coarse because of concentration of kankars.
iv. The colour of the soil is lighter.
iv. The soil is comparatively darker in colour.
v. It lies near to the flood plains.
v. It is slightly above from the flood plains.
Western Ghats and Eastern Ghats ( Put it in a tabular column)
i. Western Ghats mark the western boundary of the peninsular plateau, stretching from Gujarat to Kerala.
i. Eastern Ghats mark the eastern boundary of the peninsular plateau, stretching from Orissa to Kerala.
ii. It is a regular stretch of highland.
ii. They are dissected and irregular because of the major rivers flowing through them.
iii. Western ghats are comparatively more in height i.e. from 900-1600m.
iii. Height of eastern ghats is comparatively less than western ghats ranging from 600- 900m.
iv. Western ghats receive more rainfall due to orographic rainfall.
iv. Rainfall received is comparatively less because the monsoon winds move parallel to the eastern ghats.
v. Highest peak of western ghats is Anai Mudi, followed by Doda Betta.
v. Highest peak of eastern ghats is Mahendragiri.
Western Coastal Plains and Eastern Coastal Plains ( Put it in a tabular column)
i. Western Coastal Plains is a belt of plain region lying towards west between western ghats and Arabian sea.
i. Eastern Coastal Plains is a belt of plain region lying towards the east between eastern ghats and Bay of Bengal.
ii. This belt of plains is narrow in width.
ii. Eastern Coastal Plains are comparatively wider.
iii. Western coastal plains are less fertile because no major river is engaged in sediment deposition.
iii. Eastern coastal plains are very fertile because rivers like Mahanadi, Godavari, Krishna, Kaveri deposit their sediments during delta formation.
iv. Western plains receive more rainfall.
iv. Eastern plains receive comparatively lesser rainfall.
v. From North to South, Western Coastal plains are divided into Konkan Coast, Kannad Coast and Malabar Coast.
v. From North to South, Eastern Coastal plains are divided into Northern Circars and Coromandal Coast.
ANDAMAN AND NICOBAR ISLANDS & LAKSHADWEEP ISLANDS ( Put it in a tabular column)
i. These island groups are located in Bay of Bengal.
i. These islands are located in Arabian Sea.
ii. They are volcanic in origin.
ii. They are formed because of coral deposition.
iii. Andaman and Nicobar is a chain of islands.
iii. Lakshadweep is a cluster of islands.
iv. These island groups are far away from the mainland.
iv. This island group is closer to the mainland.
v. Administrative unit is Port Blair.
v. Administrative unit is Kavarati.
Q.23. Give the characteristics features of the Indian desert.
Ans. a. Indian desert is an undulating sandy plain covered with sand dunes.
- The region receives very low rainfall below 150mm per year.
- The region has arid climate with low vegetation cover.
- Barchans (crescent shaped dunes) and sand dunes cover large area of the desert.
- Luni is the only major seasonal river in this region.
Q.24. How can you say that the diverse physical features of India makes the country richer in its natural resources?
Ans. a. The northern mountains are the major source of water and forest wealth.
- The northern plains provide us with number of agricultural crops.
- The plateau is the store house of the minerals which is highly important for the industrialization of the country.
- The coastal region and island groups provide sites for fishing and port activities. Thus, we can say that the diverse physical features of India make the country richer in its natural resources.
ideal 9 