UPSC Prelims 2008 Q24: Geography – Indian Rivers & Water Resources
Consider the following pairs:
Tributary River - Main River
1. Chambal : Narmada
2. Sone : Yamuna
3. Manas : Brahmaputra
Which of the pairs given above is/are correctly matched?
- (a) 1, 2 and 3
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) 3 only
Answer: (d) 3 only
Explanation
Checking three tributary-main river pairs
These Indian rivers are matched here to the larger rivers they flow into, with some pairings mismatched.
| Pair | Verdict | Reason |
|---|---|---|
| 1. Chambal : Narmada | Incorrect | Chambal is actually a tributary of the Yamuna (via the Ganga system), not the Narmada |
| 2. Sone : Yamuna | Incorrect | Sone (Son) is actually a tributary of the Ganga, not the Yamuna |
| 3. Manas : Brahmaputra | Correct | Manas is indeed a tributary of the Brahmaputra |
Correct tributary-main river pairs:
| Tributary | Actual main river |
|---|---|
| Chambal | Yamuna (NOT Narmada) |
| Sone (Son) | Ganga (NOT Yamuna) |
| Manas | Brahmaputra |
Answer: (d) 3 only.
Why each option is right or wrong
- (a) Incorrect. Pairs 1 and 2 (Chambal-Narmada, Sone-Yamuna) are both wrong, so '1, 2 and 3' is wrong.
- (b) Incorrect. Pair 1 (Chambal-Narmada) is wrong; Chambal flows into the Yamuna, not Narmada.
- (c) Incorrect. Pair 2 (Sone-Yamuna) is also wrong; Sone flows into the Ganga, not Yamuna.
- (d) CORRECT. Only pair 3, Manas-Brahmaputra, is correctly matched.
Key point
Manas-Brahmaputra is the only correctly matched pair — Chambal is actually a tributary of the Yamuna (not Narmada), and Sone (Son) is actually a tributary of the Ganga (not Yamuna).
Remember
Only Manas-Brahmaputra is correctly matched; Chambal flows into the Yamuna, and Sone flows into the Ganga.
Common mistakes
- Confusing Chambal's actual Yamuna tributary status with the unrelated Narmada river.
- Confusing Sone's actual Ganga tributary status with the Yamuna.
- Assuming all three listed tributary-main river pairs are automatically correct without individual verification.
Exam tip
Chambal = tributary of Yamuna (not Narmada). Sone = tributary of Ganga (not Yamuna). Only Manas-Brahmaputra is correctly matched among these three.
Sources
- NCERT Class XI Geography — India: Physical Environment — Drainage System
- Central Water Commission and National Remote Sensing Centre — India-WRIS: River Basin Atlas (Ganga and Brahmaputra basins)