NCERT Solutions for Class 11 Geography - Structure and Physiography

Q1: Choose the right answer from the four alternatives given below.
(i) Which one of the water bodies separates the Andaman from the Nicobar?
(a) 11° Channel
(b) Gulf of Mannar
(c) 10° Channel
(d) Andaman Sea
Ans: (c)

(ii) On which of the following hill range is the ‘Dodabeta’ peak situated?
(a) Nilgiri hills
(b) Anaimalai hills
(c) Cardamom hills
(d) Nallamala hills
Ans: (a)

Q2: Answer the following questions in about 30 words.
(i) If a person is to travel to Lakshadweep, from which coastal plain does he prefer and why?
Ans: The person will prefer to travel from the western coastal plains because the Lakshdweep islands are situated in Arabian Sea which distance is lowest from this coast. Therefore, it will take the least time to reach the Lakshadweep.

(ii) Where in India will you find a cold desert? Name some important ranges of this region.
Ans: The cold desert in India is located in the north eastern part of the Kashmir Himalayas, which lies between the Greater Himalayas and the Karakoram ranges.

(iii) Why is the western coastal plain is devoid of any delta?
Ans: The western coastal plains are narrow and have steep slope. The rivers flow rapidly in one part and hence they don't form any deltas. Therefore, the western coastal plain is devoid of any delta.

Q3: Answer the following questions in not more than 125 words.
(i) Make a comparison of the island groups of the Arabian Sea and the Bay of Bengal.
Ans: Island groups of Arabian Sea :

• This island group consists of about 36 islands of which 11 are inhabited.
• The Lakshadweep islands are scattered between 8° to 12°N latitudes and 71° E to 74° E longitudes.
• These are situated at the distance of 280 km to 480 km. off the Kerala coast.
• The entire island group is built of coral deposits.
• Minicoy is the largest island of 453 sq. km. area.

Island groups of Bay of Bengal :

• This island group consists of about 572 islands.
• These are situated between 6° to 14° N latitudes and 92° E to 94°E longitudes.
• It is divided into Andaman and Nicobar islands.
• These are separated by 10 degree Channel.
• These islands are an elevated portion of sub-marine mountains and some are volcanic in origin.

(ii) What are the important geomorphological features found in the river valley plains?
Ans: The valley plains are formed by the alluvial deposits brought by the rivers.

• Bhabar: It is a narrow belt ranging between 8 km and 10 km parallel to Shiwalik foothills at the break up of the slope.
• Tarai: South of Bhabar is the belt of Tarai with a width about 10 to 20 km where the most of rivers re-arrange without having any properly demarcated channel creating a marshy and swampy condition known as Tarai.
• Bhangar: It is composed of old alluvium and forms the alluvial terraces above the level of the flood plains.
• The Khadar: The flood plain which has newer alluvium is called Khadar. A newer layer is deposited by river floods every year.
• Delta: The mouth of mighty rivers also form the delta. Sunderban delta is an example.

(iii) If you move from Badrinath to Sunderbans delta along the course of the river Ganga, what major geomorphological features will you come across?
Ans:

• Badrinath is situated along Ganga river.
• The Sunderban delta is on the mouth of Ganga and Brahmaputra in Bay of Bengal.
• If we are moving from Badrinath to Sunderbans delta along the course of the river Ganga, we will come across various of geomorphological features.
• As we start moving we will come across gorges, V-shaped valleys, rapids, waterfalls, etc.
• We will also see places where tributaries meet main river Ganga.
• After sometime, we will enter into northern plains.
• We will see various erosional and depositional landforms such as sand bars, meanders, oxbow lakes and braided channels.
• At last, we will reach our destination, swampy and marshy area known as Sunderbans delta formed by the Ganga and Brahmaputra river.