121) What are 'distributaries'?
Answer:The rivers in their lower course split into numerous channels due to the deposition of silt. These channels are known as 'distributaries'.
122) How 'Punjab Plains' are formed?
Answer:The western part of the Northern Plains is called Punjab Plains, formed by the Indus and its tributaries, the larger part of this plain lies in Pakistan.
123) What does 'doab' mean?
Answer: 'Doab' is made up of two words - 'do' means two and 'ab' means water.
124) To which parts Ganga Plains are extended?
Answer:The Ganga Plain extends between Ghaggar and Teesta rivers. It is spread over the states of North India, Haryana, Delhi, U.R, Bihar, partly Jharkhand West Bengal.
125) What is 'Bhabar'?
Answer:The rivers after descending from the mountains deposit pebbles in a narrow belt of about 8 to 16 kms in width lying parallel to the slopes in width lying parallel to the slopes of the Shiwaliks, known as 'bhabar'.
126) Which region is called 'Terai Region'?
Answer:South of bhabar, the streams and rivers re-emerge and create a wet swampy & marshy region known as Terai.
127) What does 'Bhangar' mean?
Answer:The largest part of the northern plains is formed of older alluvium. It lie above the flood plains of the rivers and present a terrace like feature. This part is known as 'Bhangar'.
128) What is 'Khadar'?
Answer:The newer younger deposits of the floodplains are called khadar. They are renewed almost every year and so are fertile, thus, ideal for intensive agriculture.
129) How was Peninsular Plateau of India formed?
Answer:It was formed due to the breaking and drifting of the Gondwana land and thus, making it a part of the oldest landmass.
130) Name the two major divisions of the Peninsulas Plateau?
Answer:They are ? The Central Highlands and The Deccan Plateau.
131) Where are The Central Highlands located?
Answer:The part of the Peninsular Plateau lying to the north of the Narmada river covering a major area of the Malwa Plateau is knows as Central Highlands.
132) Which rivers drain Central Highlands?
Answer: The Chambal, the Sind, the Betwa and the Ken.
133) What is the eastward extensions of Central Plateau known as?
Answer:The eastward extensions of this plateau are locally known as the Bundelkhand and Baghelkhand and the Chotanagpur plateau.
134) Which hill ranges form the Deccan Plateau?
Answer: The Satpura range in the north while the Mahadev, the Kaimur hills and the Maikal range form its eastward extensions.
135) What is the north east extension of Deccan Plateau called?
Answer: North East extension of the Plateau is known as Meghalaya, Karbi Anglong Plateau and North Cachar hills.
136) What is the average elevation of Western Ghats?
Answer:Their average elevation is 900-1600 metres.
137) Name the highest peak of Western Ghats.
Answer:The highest peak of Western Ghats is Anai Mudi (2,695 metres).
138) Name the highest peak of Eastern Ghats.
Answer:The highest peak of Eastern Ghats is MahendraGiri (1,501 metres).
139) What is the role of Western Ghats in south west Monsoon?
Answer: The Western Ghats cause orographic rain by facing the rain bearing moist winds to rise along the western slopes of the Ghats.
140) Name the famous hill stations of Western Ghats.
Answer: The famous hill stations are Udagamandalaem popularly known as Ooty and the Kodaikanal.
141) What is Deccan Trap?
Answer:The black soil area of Peninsular Plateau is known as Deccan Trap. This is of volcanic origin, hence the rocks are igneous. These rocks have denuded over time and are responsible for the formation of black soil.
142) Where are Aravali Hills located?
Answer:The Aravali Hills lie on the western & north western margins of the Peninsular Plateau. These are highly eroded hills. They extend from Gujarat to Delhi in a southwest-northeast direction.
143) Which is the only large river of Indian Desert of Rajasthan?
Answer:The Luni river.
144) What are Barchans?
Answer:They are crescent-shaped sand dunes covering large areas of Rajasthan's Thar desert.
145) What are the local names of the Western Coastal Plains?
Answer:The northern part of the coast is called the Konkan (Mumbai - Goa), the central stretch is called the Kannad Plain (Karnataka) while the Southern stretch is referred as the Malabar Coast (Kerala).
146) By what names are Eastern Coastal plains called?
Answer: In northern part it is referred to as the Northern Circar while the Southern part is known as the Coromandel Coast.
147) Where is Chilka Lake located?
Answer: The Chilka Lake is the largest salt water lake in India. It lies in the state of Orissa, to the south of the Mahanadi Delta.
148) How are Lakshdweep Island formed?
Answer:This group of islands is composed of small coral islands. They are in horse shoe or ring shaped called atolls.
149) Name the capital of Lakshdweep.
150) How are Andaman & Nicobar Islands formed?
Answer: They are formed by volcanic eruptions in the sea (Bay of Bangal).
151) What is the contribution of Northern chain of Mountain Blocks?
Answer:The mountains are the major sources of water and forest wealth & protect India as natural barriers.
152) What is the importance of plateaus of India?
Answer: The plateaus are storehouses of minerals, which have played a crucial role in the industralisation of the country.
153) What do you mean by the 'Theory of Plate Tectonics'?
Answer: Earth scientists have explained the formation of physical features with the help of some theories and one such theory is the 'Theory of Plate Tectonics'. According to this theory, the crust i.e.- the upper part of the Earth has been formed out of seven major and some minor plates. The movement of these plates resulted in building up of stresses within the plates, leading to folding, faulting and volcanic activities.
154) What are the three types of plate movements on the Earth?
Answer: (i) Coverage boundary: When some plates come towards each other, they form a convergent boundary. It may also be called folding movements.
(ii) Divergent boundary: When some plates move away from each other they form a divergent boundary. It is also called faulting movements.
(iii) Transform boundary: In the event of two plates coming together, they may either collide and crumble or may slide under the other and form the transform boundary.
155) How were the northern plains formed?
Answer: The Himalayan uplift out of the Tethy's sea and subsidence of the northern flank of the Peninsular plateau resulted in the formation of a large basin. In due course of time, this depression gradually got filled with the deposition of the sediments by the rivers flowing from mountains in the north. A flat land with extensive alluvial deposits by these rivers led to the formation of the Northern Plains of India.
156) Name the major physiographic divisions of India.
Answer: The major physiographic divisions of India are:
(i) The Himalayan Mountains
(ii) The Northern Plains
(iii) The Peninsular Plateau
(iv) The Indian Desert
(v) The Coastal Plains
(vi) The Islands
157) Give a brief description of the Himalayan mountains.
Answer: The Himalayas, geologically young and structurally fold mountains stretch over the northern borders of India. These mountain ranges run in a west- east direction from the Indus to the Brahmaputra. The Himalayas are loftiest and one of the most rugged mountain barriers of the world. They form an arc, which covers a distance of 2,400 kilometres.
158) Describe the three parallel ranges of the Himalayas.
Answer: The three parallel ranges of the Himalayas are:
(a) Himadri (Great or Inner Himalayas) It is the most continuous range. The northernmost range is called the Himadri. It consists of loftiest peaks with an average height of 6,000 metres. It contains all the prominent peaks It remains snow covered throughout the year, resulting into the formation of glaciers and some perennial rivers.
(b) Himachal (Lesser Himalayas) It lies to the south of Himadri and forms the most rugged mountain system. The ranges are mainly composed of highly compressed and altered rocks. Average height is betwee3,700 to 4,500 metres. Some famous ranges are the Pir Panjal range, Dhaula Dhar and Mahabharat ranges. It has some famous valleys like Kullu, Kangra and Kashmir. They are known for their hill stations. The average width is 50 Km.
(c) Shiwaliks (Outer Himalayas) This is the outermost range of the Himalayas. Its height varies between 900 and 1,100 metres. These ranges are composed of unconsolidated rock material, so these ranges are prone to earthquakes and landslides. These longitudinal valleys lying between lesser Himalayas and Shiwaliks are called 'Duns' like Dehra Dun, Kotii Dun and Patlin Dun, etc.
159) Name the highest peaks of the Himalayas with their heights.
|(i) Mt. Everest|| 8,848 metres, Nepal|
|(ii) Kanchenjunga || 8,598 metres, India|
|(iii) Dhaulagiri||8,172 metres, Nepal|
|(iv) Nanga Parbat||8,126 metres, India|
|(v) Annapurna ||8,078 metres, Nepal|
|(vi) Nanda Devi ||7,817 metres, India|
|(vii) Kamet||7,756 metres, India|
|(viii) Namcha Barwa||7,756 metres, India|
|(ix) Guria Mandhata||7,728 metres, Nepal |
160) Why are the Shiwalik ranges prone to earthquakes?
Answer: The Shiwalik ranges are still in the process of folding. This is the youngest range of the Himalayas formed by unconsolidated rock material. Therefore, these ranges are prone to earthquakes and landslides.
161) Classify the Himalayas on the basis of regions from the West to East.
Answer: This division of the Himalayas is demarcated by the river valleys.
(i) Punjab Himalayas: This part of the Himalayas lies between the rivers Indus and Satluj. It is also known as Kashmir and the Himachal Himalayas.
(ii) Kumaon Himalayas: This part of the Himalayas lies between Satluj and Kali rivers.
(iii) Nepal Himalayas: This part of the Himalayas lies between Kali and Teesta rivers.
162) What do you know about 'Purvanchal?
Answer: The Eastern Hills are collectively known as Purvanchal. These hills running through the north-eastern states are mostly composed of strong sandstones which are sedimentary rocks. They are covered with dense forest; they mostly run as parallel ranges and valleys. Purvanchal comprises of the Mizo hills, Naga hills, Manipur hills, Patkai Bum, Garo, Khasi and Jaintia hills.
163) Why are the Northern Plains the agriculturally productive parts of India?
Answer: The Northern Plains are drained by three river systems?the Indus, Ganga and the Brahmaputra along with their tributaries. They deposit alluvial soils in vast basins lying at the foothills of the Himalayas. With a rich soil cover combined with adequate water supply and favourable climate, it is agriculturally a very productive part of India.
164) How are riverine islands formed?
Answer: The rivers coming from the northern mountains carry alluvium with them and do the depositional work. In the lower course, due to gentle slope, the velocity of the river decreases which results in the formation of riverine islands.
165) Classify the Northern Plains on the basis of its location.
Answer:The Northern Plains are broadly divided into three sections:
(i) Punjab Plains: The western part of the Northern Plain is called the Punjab Plains. It is formed by the river Indus and its tributaries.
(ii) Ganga Plains: It extends between Ghaggar and Teesta rivers. It is spread over the states of North India, i.e., Delhi, Haryana, UP, Bihar and parts ofJharkhand and West Bengal.
(iii) Brahmaputra Plains: To the east of the Ganga plain lies the Brahmaputra Plain. They cover the areas of Assam and Arunachal Pradesh.
166) Write any three characteristics of the Central Highlands.
Answer: The part of the Peninsular plateau lying to the north of the Narmada river, covering a major area of the Malwa plateau is known as the 'Central Highlands'. Its three characteristics are:
(i) They stretch from the north-west with the Aravalis, further merging with the sandy and rocky desert of Rajasthan.
(ii) They are wider in the West but narrower in the east.
(iii) The eastward extension of this plateau is locally known as Bundelkhand and Baghelkhand. The Chota Nagpur plateau is the easternmost part of this plateau, which is drained by the river Damodar.
167) Differentiate between western coastal plains and eastern coastal plains.
Answer: Western Coastal Plains
(i) It is a narrow plain.
(ii) This part of the plain receives rains from South West Monsoons.
(iii) Narmada and Tapti rivers flow from it, forming estuaries.
Eastern Coastal Plains
(i) It is a wide and levelled plain.
(ii) Coromandel Coast receives rains from North East Monsoons.
(iii) All the major peninsular rivers form a delta by making the land fertile.
168) Where are the famous Passes of Himalayas located?
Answer: Shipkila Pass: It is located on the Tibet-Himalaya Road. It lies in the Satluj valley in Himachal Pradesh. Nathula Pass: It is on the way from India to Lhasa. It lies in the Chumbi valley in Sikkim. Bomdila Pass: It lies further east in Arunachal Pradesh. It leads to Arunachal- China border.
169) What do you know about valleys and duns in Himalayas?
Answer: The Kashmir valley is so beautiful that it is described as 'paradise on the earth'. The Kangra and Kullu valleys in Himachal Pradesh are also beautiful. The Kathmandu valley in Nepal is famous as well. Small valleys in Kumaon Himalayas of Uttarakhand are called 'duns'. Some of the famous duns are Dehra Dun, Kotii Dun and Patii Dun.
170) Give some important characteristics of Northern Plains.
Answer: (i) The Northern Plains of India lie between the Himalayas in the north and Peninsular Plateau in the South.
(ii) They are made of the fine silt or alluvium, brought down by rivers from the Himalayas and the Peninsular Plateau.
(iii) These plains are one of the world's most extensive and fertile plains. They are drained by three major rivers?the Indus, the Ganga and the Brahmaputra and their tributaries.