CDS Geography · Indian Geography — Physical Features
Islands and Sea Channels
The Andaman and Nicobar Islands and Lakshadweep: the sea channels between them, their peaks and the tribes who live there.
Why this matters
Nine CDS questions from 2018 to 2026, 4 EASY and 5 MODERATE, none HARD. The Ten Degree Channel alone has been asked three times, so these are some of the surest marks in the chapter.
Concept 1 of 3: Sea channels and straits
Several channels are named after the line of latitude they follow. The Ten Degree Channel runs along 10°N and cuts the Andaman group off from the Nicobar group. The Eight and Nine Degree Channels lie on the other side of India, in the Arabian Sea, around Minicoy.
Definition
Two seas, two island groups:
- In the Bay of Bengal: the Ten Degree Channel separates the Andaman group from the Nicobar group.
- In the Arabian Sea: the Nine Degree Channel separates Minicoy from the rest of Lakshadweep, and the Eight Degree Channel separates Minicoy from the Maldives.
- The Palk Strait separates Tamil Nadu from Sri Lanka.
| Channel | What it separates |
|---|---|
| Ten Degree Channel | Little Andaman (Andaman group) from Car Nicobar (Nicobar group)Q CDS 2019 (I) and 2021 (I): the 10°N line is the answer for Andaman versus Nicobar. |
| Duncan Passage | South Andaman from Little Andaman |
| Coco Channel | North Andaman from the Coco Islands of Myanmar |
| Great Channel | Great Nicobar from Sumatra (Indonesia) |
| Nine Degree Channel | Minicoy from the main Lakshadweep islands |
| Eight Degree Channel | Minicoy (Lakshadweep) from the MaldivesQ CDS 2018 (II): Lakshadweep from Maldives, not Andaman from Nicobar. |
| Palk Strait | Tamil Nadu from Sri Lanka |
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2022 · CDS (I) 2022 — General Knowledge · Q72Easy
Example 1 · Indian Geography — Physical Features · Islands and Sea Channels
Ten Degree Channel is found between :
Ten Degree is Andaman and Nicobar
The Ten Degree Channel is in the Bay of Bengal, between Little Andaman and Car Nicobar. The Eight and Nine Degree Channels belong to Lakshadweep in the Arabian Sea.
Concept 2 of 3: Andaman, Nicobar and Lakshadweep
India's islands come in two very different sets. The Andaman and Nicobar Islands in the Bay of Bengal are the tops of a drowned mountain range, so they are hilly and have peaks. Lakshadweep in the Arabian Sea is made of coral, so its islands are small and flat.
Definition
Key facts:
- Andaman group (north): highest point Saddle Peak in North Andaman; Mount Diavolo in Middle Andaman; Port Blair in South Andaman.
- Nicobar group (south): Mount Thuillier (642 m) on Great Nicobar. Indira Point, India's southern tip, is also on Great Nicobar.
- Barren Island in the Andaman Sea is India's only active volcano.
- Lakshadweep: coral islands, capital Kavaratti, total area about 32 sq km, the smallest Union Territory.
| Island group | Facts to remember |
|---|---|
| Andaman group | Saddle Peak (North Andaman), Mount Diavolo (Middle Andaman), Port Blair (South Andaman)Q CDS 2022 (II): Lhotse is a Himalayan peak next to Everest, not an island peak. |
| Nicobar group | Mount Thuillier and Indira Point, both on Great Nicobar |
| Barren Island | India's only active volcano, in the Andaman Sea |
| Lakshadweep | Coral islands; capital Kavaratti; about 32 sq km, the smallest UTQ CDS 2020 (II): smaller than Chandigarh, Puducherry and Dadra and Nagar Haveli and Daman and Diu. |
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2022 · CDS (I) 2022 — General Knowledge · Q87Moderate
Example 2 · Indian Geography — Physical Features · Islands and Sea Channels
Mount Thullier (642 m) is an important mountain peak of Andaman and Nicobar Islands. It is located in :
Lakshadweep is coral, the Andamans are hills
The Andaman and Nicobar Islands are a drowned mountain range with peaks over 600 m. Lakshadweep is coral and flat. A question about a peak is always about the Andaman and Nicobar Islands.
Concept 3 of 3: Tribes of the Andaman and Nicobar Islands
Five small, ancient tribes of the islands are listed as particularly vulnerable tribal groups. Four live in the Andamans and one, the Shompen, in the forest of Great Nicobar. Tie each tribe to its island.
Definition
The five vulnerable groups:
- Great Andamanese: Strait Island.
- Onge: Little Andaman.
- Jarawa: western coast of South and Middle Andaman.
- Sentinelese: North Sentinel Island.
- Shompen: interior of Great Nicobar.
The Nyishi are not island people: they are the largest tribe of Arunachal Pradesh.
| Tribe | Island |
|---|---|
| Great Andamanese | Strait Island |
| Onge | Little Andaman |
| Jarawa | South and Middle Andaman (west coast) |
| Sentinelese | North Sentinel Island |
| Shompen | Great Nicobar (interior forest)Q CDS 2019 (I): the Shompen belong to the Andaman and Nicobar Islands, not Jharkhand or Odisha. |
Practice this conceptself-check · 3 quick reps
The same idea in a real exam question:
CDS · 2026 · CDS (I) 2026 — General Knowledge · Q104Easy
Example 3 · Indian Geography — Physical Features · Islands and Sea Channels
Which among the following tribes inhabit the Andaman and Nicobar Islands?
1. Onge
2. Jarawas
3. Sentinelese
Select the answer using the codes given below :
The Shompen are the one Nicobar tribe
Four of the five vulnerable island tribes live in the Andamans. The Shompen are the one that lives in the Nicobar group, on Great Nicobar.
Summary — formulas & gotchas at a glance
A revision cheat-sheet for the formulas and gotchas above. Click any concept name to jump back to its full explanation.
Reference tables (3)
Sea channels and straits7 rows
| Channel | What it separates |
|---|---|
| Ten Degree Channel | Little Andaman (Andaman group) from Car Nicobar (Nicobar group)Q CDS 2019 (I) and 2021 (I): the 10°N line is the answer for Andaman versus Nicobar. |
| Duncan Passage | South Andaman from Little Andaman |
| Coco Channel | North Andaman from the Coco Islands of Myanmar |
| Great Channel | Great Nicobar from Sumatra (Indonesia) |
| Nine Degree Channel | Minicoy from the main Lakshadweep islands |
| Eight Degree Channel | Minicoy (Lakshadweep) from the MaldivesQ CDS 2018 (II): Lakshadweep from Maldives, not Andaman from Nicobar. |
| Palk Strait | Tamil Nadu from Sri Lanka |
Andaman, Nicobar and Lakshadweep4 rows
| Island group | Facts to remember |
|---|---|
| Andaman group | Saddle Peak (North Andaman), Mount Diavolo (Middle Andaman), Port Blair (South Andaman)Q CDS 2022 (II): Lhotse is a Himalayan peak next to Everest, not an island peak. |
| Nicobar group | Mount Thuillier and Indira Point, both on Great Nicobar |
| Barren Island | India's only active volcano, in the Andaman Sea |
| Lakshadweep | Coral islands; capital Kavaratti; about 32 sq km, the smallest UTQ CDS 2020 (II): smaller than Chandigarh, Puducherry and Dadra and Nagar Haveli and Daman and Diu. |
Tribes of the Andaman and Nicobar Islands5 rows
| Tribe | Island |
|---|---|
| Great Andamanese | Strait Island |
| Onge | Little Andaman |
| Jarawa | South and Middle Andaman (west coast) |
| Sentinelese | North Sentinel Island |
| Shompen | Great Nicobar (interior forest)Q CDS 2019 (I): the Shompen belong to the Andaman and Nicobar Islands, not Jharkhand or Odisha. |
Watch out for (3)
- Ten Degree is Andaman and Nicobar→ Sea channels and straits
- Lakshadweep is coral, the Andamans are hills→ Andaman, Nicobar and Lakshadweep
- The Shompen are the one Nicobar tribe→ Tribes of the Andaman and Nicobar Islands
Test yourself on Indian Geography — Physical Features
20 past CDS questions from this chapter, timed at 20 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.