Wednesday, 22 August 2012

Class IX - Physical Features of India

Questions in the Exercise
Q.1. Choose the right answer from the four alternatives given below :
(i) A landmass bounded by sea on three sides is referred to as
(a) Coast (b) Island (c) Peninsula (d) None of the above.
Ans. Peninsula
(ii) Mountain ranges in the eastern part of India forming its boundaries with Myanmar
are collectively called :
(a) Himachal (b) Uttaranchal   (c) Purvanchal (d) None of the above.
Ans. Purvanchal
(iii)The western coastal strip south of Goa is referred to as
(a) Coromandel (b) Konkan (c) Kannad (d) Northern Circar
Ans. Konkan
(iv) The highest peak in the Eastern Ghats is
(a) Anai Mudi (b) Kanchenjunga    (c) Mahendragiri  (d) Khasi
Ans. Mahendragiri
Q.2. Answer the following questions briefly
(i) What are tectonic plates ?
Ans. Large fragments of the Earth’s crust torn due to the rising currents are called tectonic plates.
(ii) Which continents of today were part of the Gondwanaland? (CBSE - 2010)
Ans. South America, Africa and Australia.
(iii) What is the ‘Bhabar’?
Ans. Bhabar is a pebble studded formation situated at the junction of mountain and plain.
(iv) Name the three major divisions of the Himalayas from north to south.
Ans. The Great or the Inner Himalayas or the Himadri, the Middle Himalayas or the Himachal, and
the Outer Himalayas or the Shivaliks.
(v) Which plateau lies between the Aravali and the Vindhya ranges?
Ans. The Malwa plateau lies between the Aravali and the Vindhya Ranges.
(vi) Name the island group of India having coral origin.
Ans. Lakshadweep Islands is the island group of India having coral origin.
Q.3. Distinguish between
(i) Converging and Diverging Tectonic Plates.
Ans. Converging Plates                                                     Diverging Plates
(a) When tectonic plates move towards                      (a) When tectonic plates move away from
each other, they are called converging plates.                    each other, they are termed as diverging plates.
 (b) When they move towards each other,                   (b) When they move away from each other,
they collide or crumble or one of                                       they do not collide or crumble.
them slides under the other.
(c) Converging plates cause folds                                    (c) Diverging plates cause fractures in the crust.
in the crust.

(ii) Distinguish between Bangar and Khadar.
Ans. Bangar                                                                       Khadar
(a) Formed of older alluvium                                         (a) Renewed every year.
(b) Lies above flood plains of rivers.                              (b) Is newer, younger deposit of flood
(c) Presents a terrace like feature.                         (c) Contains calcerous deposits  locally known as Kankar.
(d) Less fertile                                                             (d) More fertile

(iii) Distinguish between the Western Ghats and the Eastern Ghats.
Ans.  Western Ghats                                                            Eastern Ghats
(a) They stand like a continuous wall and                         (a) They are discontinuous and irregular.
can be crossed through passes only.                                     They have been dissected by rivers
Thal Ghat provides passage to rails and roads.                     which have made their passages to
                                                                                           reach the Bay of Bengal.
(b) This range is a source of many large rivers.                    (b) No big river originates from this range.
(c) It obstructs the monsoon winds coming                          (c) They are almost parallel to 
 from the Arabian Sea which causes                                          the monsoons originating in the   
heavy rainfall in the Western Coastal Plains                                monsoons originating in the Bay
                                                                                              of Bengal and do not cause much rainfall.
Q.4. Describe how the Himalayas were formed.
Ans. Geologists claim that a sea was located where the Himalayas now stand. Internal and external
changes of Earth’s crust occurred. It is said that one of the crustal plates, called the Indo-
Australian plate, separated from the super-continent named Gondwanaland. It drifted slowly
towards the north to collide with the Eurasian plate five million years ago. The northern edge
of the Indo-Australian plate was pushed beneath the Eurasian plate. After the collision of these
two plates, the sedimentary rocks of enclosed ocean folded to form the Himalayas.
Q.5. Which are the major physiographic divisions of India? Contrast the relief of the
Himalayan region with that of the Peninsular Plateau.
Ans. The major physiographic divisions of India are :
(i) The Great Mountains of the North. (ii) The North Indian Plain.
(iii) The Peninsular Plateau (iv) The Coastal Plains and
(v) The Islands.
Himalayan Region                                                              Peninsular Plateau
(a) This  region comprises greatest and                          (a) Rugged and dissected terrain plateau is
highest mountain ranges                                                      a remnant portion of the supercontinent
of the world.                                                                      the Gondwanaland.
(b) The ranges have I-shaped                         (b) It has horsts, rift valleys and troughs and U-shaped valleys.
(c) It is the origin of perennial rivers.                             (c) It has rainfed, seasonal rivers.
(d) Young fold mountains made from the                       (d) Created from igneous and metamorphic
uplift of the strata formed by the sedimentary rocks.            rocks after splitting of Gondwanaland.

(e) Parallelly arranged mountain                                    (e) Rivers dissect. Faults and vertical
ranges are separated by valleys and plains.                         movement of the Earth mark the plateau.

Q.6. Give an account of the Northern Plains of India.
Ans. The Northern Plains have been formed from the alluvium that the mountain rivers deposited
here. This turned the soil on the surfaced land fertile for growing a rich harvest of variety of
crops. This led to the development of the Indus River Valley Civilisation. The rich soil was
further aided by favourable climate and constant water supply from the rivers. Between the
mouths of the Indus and the Ganga-Brahmaputra, the North Indian Plain covers a distance of
3200 km. It is 300 to 150 km wide at some places. The North Indian Plains have the Indus
river system in the west and the Ganga-Brahmaputra river system in the east. The first includes
Jhelum, Chenab, Ravi, Beas, Satluj. The Indus flows into the Arabian Sea.
The second includes Ganga, its tributaries and the Brahmaputra which combine as Meghna as
they drain into the Bay of Bengal. They form the world’s largest and fastest growing delta.
The difference in relief has led the North Indian Plains to be divided into four zones :
(i) Bhabhar, (ii) Tarai, (iii) Bangar and (iv) Khadar.
Q.7. Write short notes on the following.
(i) The Indian Desert
Ans. Lying towards the western margins of the Aravali Hills, the Indian desert is formed of sandy
plain covered with sand dunes. Receiving less than 10 mm rainfall in a year, the region has
arid climate, low vegetation and streams that appear only in the rainy season. But they soon
disappear into the sands, lacking enough water to reach the sea. Large areas of the deserts have
crescent shaped sand dunes, i.e. barchans, while longitudinal dunes are abundant near Indo-Pakistan boundary.
(ii) Central Highlands.
Ans. The northern part of the Peninsular Plateau consists of plateaus, denuded mountain ranges and
low hills made of igneous rocks. In the north-west are the Aravali range, running in south-west,
north-east direction forming a discontinuous ridge. Thar Desert lies to the west of Aravali
ranges. The southern boundary is demarcated by the Vindhya Range with Kaimur Hills in the
eastern extent. The Malwa plateau lies between Aravalis and Vindhyas. Between the valleys
of Narmada and the Son, escarpments are formed by the Vindhyan Kaimur range.
(iii) Island groups of India.
Ans. The Lakshadweep consists of many small islands located opposite the Kerala coast in the
Arabian Sea. The islands of this group are formed of coral deposits called ‘atolls’ in
Malayalam which refer to their ring or ‘horse-shoe’ shape. The Andaman and Nicobar Islands,
on the other hand, are larger in size. They are more in number and more widely scattered.
There are about 200 islands in the Andaman group and 19 islands in the Nicobar group.

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