Class IX – Physical Features of India

Ans. Six physiographic divisions are as given below:

(i) The Himalayan Mountains

(ii) The Northern Plains

(iii) The Peninsular Plateau

(iv) The Indian Desert

(v) The Coastal Plains

(vi) The Islands

Ans. (i) The Himadri

(ii) The Himachal

(iii) The Shiwaliks

Ans. (i) The Punjab Himalayas

(ii) The Nepal Himalayas

(iii) The Assam Himalayas

(iv) Purvachal or Eastern Hills

Ans. (i) The longitudinal valley lying between lesser Himalayas and Shiwaliks are known as Duns.

(ii) Dehradun, Kotli Dun and Patli Dun are well-known duns.

Ans. The Northern Plain has been formed by the interplay of the three major river systems, namely – the Indus, the Ganga and the Brahmaputra along with their tributaries.

Ans. Doab is made up of two words, ‘do’ meaning two and ‘ab’ meaning water. Similarly, ‘Punjab’ is also made up of two words – ‘Punj’ meaning five and ‘ab’ meaning water. Thus, land of two rivers and five rivers respectively.

Ans. The Northern plains can be divided into four regions i.e., Bhabar, terai, Bhangar and Khadar.

Ans. The Peninsular Plateau was formed due to the breaking and drifting of the Gondwana Land, thus making it a part of the oldest land mass.

Ans. The Central Highlands are wider in the west but narrower in the east.

Ans. The Western Ghats are higher than the Eastern Ghats. Their average elevation is 900-1000 metres as against 600 metres of the Eastern Ghats.

Ans. It has arid climate and low vegetation cover. Streams appear during the rainy seasons.

Ans. Luni

Ans. The Western Coast sandwiched between the Western Ghats and the Arabian Sea, is a narrow plain.

Ans. India’s only active volcano is found on Barren island in Andaman and Nicobar group of islands.

Ans. Andaman and Nicobar Islands.

Ans. (a) Himalayan mountains:

(i) From the view point of geology, Himalayan mountains form an unstable zone.

(ii) The whole mountain system of Himalaya represents a very youthful topography with high peaks, deep valleys and fast flowing rivers.

(iii) These are structurally fold mountains.

(b) Peninsular Plateau:

(i) Geologically the Peninsular Plateau constitutes one of the ancient landmasses on the earth’s surface.

(ii) It was supposed to be one of the most stable land blocks.

Ans. The main features of the Himachal or lesser Himalayas are as follows:

(i) It is the most rugged mountain system.

(ii) It is composed of highly compressed and altered rocks.

(iii) Its altitude varies between 3,700 or 4,500 metres and the average width is of 50 kim.

(iv) Its prominent ranges are the Pir Panjal, the Dhaula Dhar and the Mahabharat. The Pir Panjal range is the longest range.

(v) The famous Kashmir valley and the Kangra and the Kullu valley are situated in this range.

(vi) This region is well known for hill stations, namely, Mussoorie, Nainital and Ranikhet.

Ans. The features are as follows:

(i) It is the most continuous range consisting of the loftiest peaks with an average height of 6,000 metres. All the prominent Himalayan peaks are in this range.

(ii) Its folds are asymmetrical in nature.

(iii) the core of this part of the Himalayas is composed of granite.

(iv) It is perennially snow bound.

(v) A number of glaciers descend from it.

Ans. (i) They extend over a width of 10-50 km

(ii) their altitude vary between 900 and 1,100 metres.

(iii) These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north.

(iv) These valleys are covered with thick gravel and alluvium.

(v) The longitudinal valley lying between lesser Himalayas and the Shiwaliks are known as Duns. Dehra Dun, Kotli Dun and Patli Dun are some of the well-known Duns.

Ans. The divisions of the Himalayas demarcated by the river valleys are as given below:

(i) Punjab Himalayas: The part of Himalayas lying between Indus and Satluj has been traditionally known as Punjab Himalayas. It is also known regionally as Kashmir and Himachal Himalaya from the west to east.

(ii) Kumaon Himalayas: It is the part of the Himalayas lying between the Sutluj and the Kali rivers.

(iii) Nepal Himalayas: It is the part of the Himalayas lying between the Kali and the Teesta rivers.

(iv) Assam Himalayas: It is demarcated by the Teesta and the Dihang rivers.

Ans. (a) In the northern plains, south of the bhabar region, the streams and rivers re-emerge and create a wet, swampy and marshy region that is known as terai.

(b) Once it was a thickly forested region full of wild life.

(c) However, at the time of Partition of India, the forests had been cleared to create agricultural land.

(d) The migrants from Pakistan were settled here

(e) Dudhwa National Park on Indo-Nepal border in Uttar Pradesh is in this region.

Ans. (a) Beyond the Dihang gorge, the Himalayas bend sharply to the south and spread along the eastern boundary of India.

(b) They are known as the Purvachal or the Eastern hills and mountains.

(c) These are composed of strong sandstones which are sedimentary rocks.

(d) They are covered with dense forests. They run as parallel ranges and valleys.

(e) The Purvachal comprises the Patkai hills, the Naga hills, the Manipur hills and the Mizo hills.

Ans. (i) The Mahadev, the Kaimur hills and the Maikal range form the eastern extension of the Central Highlands.

(ii) The Chotanagpur Plateau is the eastern extension of the Central Highlands.

(iii) An eastern extension of the Central Highlands is formed by the Raj Mahal Hills, to the south of which lies large reserve of mineral resources in the Chotanagpur Plateau.

Ans. Each physiographic region complements the other and makes the country richer in its natural resources.

(i) The northern mountains are the major sources of water and forest wealth.

(ii) The northern plans are the granaries of the country. They provide the base for early civilisations.

(iii) The plateau is a store-house of minerals which has played a crucial role in the industrialization of the country.

(iv) The coastal region and island groups provide sites for fishing and port activities. Thus, the diverse physical features of the land have immense future possibilities of development.