Class | Subject | Book | Chapter | Session | Questions covered |
|---|---|---|---|---|---|
XI | Geography | India: Physical Environment (NCERT) | 2 – Structure and Physiography | 2026-27 | 8 of 8 |
Chapter at a glance
Division | Key points |
|---|---|
Northern and north-eastern mountains | Himalayas (Himadri, Himachal, Shiwaliks) and Purvanchal; sub-divisions: Kashmir, Himachal–Uttarakhand, Darjeeling–Sikkim, Arunachal, Eastern hills |
Northern plain | Formed by Indus, Ganga, Brahmaputra deposits; bhabar, tarai, bhangar (old alluvium), khadar (new alluvium) |
Peninsular plateau | Oldest landmass; Deccan plateau, Central Highlands, North-eastern plateau; Western and Eastern Ghats; Anaimudi (2,695 m) highest peak, Dodabeta in Nilgiris |
Indian desert | Thar; arid, sand dunes, barchans; Luni river |
Coastal plains | Western (narrow, submerged, no deltas, natural ports) and Eastern (broad, emergent, deltas) |
Islands | Bay of Bengal: Andaman and Nicobar (Ten Degree Channel); Arabian Sea: Lakshadweep (coral) |
Exercise Questions
Question 1 (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
Answer
The Andaman group lies north and the Nicobar group south of the Ten Degree Channel.
- 10° Channel
Question 1 (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
Answer
Dodabeta (2,637 m) is the highest peak of the Nilgiri hills.
- Nilgiri hills
Question 2 (i)
If a person is to travel to Lakshadweep, from which coastal plain does he prefer and why?
Answer
The person would prefer the western coastal plain, specifically the Malabar coast of Kerala (e.g. Kochi). Lakshadweep lies in the Arabian Sea only about 220–440 km off the Kerala coast, and Kochi has good port and ship services to the islands.
The western (Malabar/Kerala) coastal plain, as Lakshadweep lies just 220–440 km off the Kerala coast with ship links from Kochi.
Question 2 (ii)
Where in India will you find a cold desert? Name some important ranges of this region.
Answer
The cold desert lies in Ladakh, in the trans-Himalayan region of the Kashmir Himalayas (north of the Great Himalayas). Important ranges: Karakoram, Ladakh and Zaskar ranges.
In Ladakh; ranges include the Karakoram, Ladakh and Zaskar.
Question 2 (iii)
Why is the western coastal plain devoid of any delta?
Answer
- The western coastal plain is narrow and a submerged coast, so rivers have no broad plain on which to deposit sediment.
- Rivers flowing west (from the Western Ghats) are short and swift, carrying little silt; large rivers like the Narmada and Tapi flow through rift valleys and form estuaries instead.
Because it is a narrow, submerged coast where short, swift rivers (and the Narmada and Tapi in rift valleys) form estuaries rather than deltas.
Question 3 (i)
Make a comparison of the island groups of the Arabian Sea and the Bay of Bengal.
Answer
Basis | Bay of Bengal islands (Andaman and Nicobar) | Arabian Sea islands (Lakshadweep and Minicoy) |
|---|---|---|
Number | About 572 islands/islets | About 36 islands, 11 inhabited |
Location | Roughly 6°N–14°N and 92°E–94°E | Between 8°N–12°N and 71°E–74°E, 220–440 km off Kerala |
Origin | Elevated portions of submarine mountains; some volcanic (Barren Island — India’s only active volcano, Narcondam) | Built of coral deposits (atolls) |
Relief | Hilly, with peaks such as Saddle Peak (738 m) | Low, flat; storm beaches of pebbles and boulders on the east |
Division | Andaman (north) and Nicobar (south) separated by the Ten Degree Channel | Divided by the Nine Degree Channel (Amini to the north, Cannanore to the south) |
Size | Larger islands; dense forests, equatorial climate | Small islands; Minicoy the largest (453 ha) |
Andaman–Nicobar: many large, hilly, partly volcanic islands of submarine-mountain origin, split by the Ten Degree Channel. Lakshadweep: about 36 small, flat coral islands off Kerala, split by the Nine Degree Channel.
Question 3 (ii)
What are the important geomorphological features found in the river valley plains?
Answer
In the northern river plains, from the mountains towards the sea:
- Bhabar: a narrow belt (8–10 km) of pebbles and boulders at the foot of the Shiwaliks, where streams disappear.
- Tarai: south of the Bhabar, 10–20 km wide, where streams re-emerge, forming marshy, swampy land.
- Bhangar: older alluvium on higher terraces, with kankar nodules.
- Khadar: younger, fertile alluvium on floodplains renewed every year.
Other features: sand bars, meanders, oxbow lakes, braided channels, levees, floodplains, and riverine islands; in the lower course, deltas (e.g. Sunderbans) and estuaries.
Bhabar, tarai, bhangar and khadar belts; plus meanders, oxbow lakes, braided channels, sand bars, levees, floodplains and deltas.
Question 3 (iii)
If you move from Badrinath to Sunderbans delta along the course of the river Ganga, what major geomorphological features will you come across?
Answer
- Upper course (Badrinath to Haridwar): high mountains, glaciers (Gangotri), deep V-shaped valleys, gorges, waterfalls and rapids; confluences such as Deva Prayag (Alaknanda and Bhagirathi).
- Foothills (around Haridwar): bhabar (pebble and boulder belt) and tarai (marshy belt) where the river enters the plains; alluvial fans.
- Middle course (plains of UP and Bihar): broad floodplains with bhangar (older) and khadar (newer) alluvium, meanders, oxbow lakes, levees, sand bars, braided channels.
- Lower course (West Bengal): very gentle slope, river splits into distributaries; formation of the Ganga–Brahmaputra delta (Sunderbans) with tidal creeks, mangrove swamps (char and bils), and estuarine features near the sea.
Glaciers, gorges and V-shaped valleys in the mountains; bhabar, tarai and alluvial fans at the foothills; floodplains, meanders, oxbow lakes, levees in the plains; distributaries, delta, mangroves and tidal creeks in the Sunderbans.
Topic checklist
- Geological divisions: Peninsular block, Himalayas, Indo-Ganga-Brahmaputra plain
- Northern and north-eastern mountains and their sub-divisions
- Northern plain: bhabar, tarai, bhangar, khadar
- Peninsular plateau, Indian desert
- Coastal plains and islands