Q30. Which river–tributary pair is correct?
1. Chambal–Narmada;
2. Son–Yamuna;
3. Manas–Brahmaputra.
[UPSC CSE Prelims (2008)]
(A) 1, 2 and 3
(B) 1 and 2 only
(C) 2 and 3 only
(D) 3 only
Answer: (D) 3 only
Explanation: Chambal joins the Yamuna, not the Narmada; Son joins the Ganga, not the Yamuna. Only Manas is correctly paired with the Brahmaputra. Himalayan sediment, seasonal floodwater and heavy rainfall strongly shape the river channels and adjoining plains.
Q29. On which river is the ancient Grand Anicut located?
[UPPCS Prelims (2008)]
(A) Godavari
(B) Krishna
(C) Cauvery
(D) Vaigai
Answer: (C) Cauvery
Explanation: Grand Anicut, or Kallanai, is an ancient barrage built across the Cauvery in Tamil Nadu to divert water through irrigation channels. Regional relief, river outlets and tributary connections help distinguish the surrounding drainage basin geographically.
Q28. Which river originates at Amarkantak?
[UPSC CSE Prelims (2007)]
(A) Damodar
(B) Mahanadi
(C) Narmada
(D) Tapi
Answer: (C) Narmada
Explanation: Narmada emerges at Amarkantak in Madhya Pradesh and follows a westward rift course. Damodar rises in Chota Nagpur, Mahanadi in Chhattisgarh and Tapi near Multai. Regional relief, river outlets and tributary connections help distinguish the surrounding drainage basin geographically.
Q27. Assertion: Kali Nadi is an east-flowing South Indian river.
Reason: The Deccan Plateau slopes chiefly eastwards.
[UPSC CSE Prelims (2007)]
(A) Both true, reason explains
(B) Both true, reason not explanation
(C) Assertion true, reason false
(D) Assertion false, reason true
Answer: (D) Assertion false, reason true
Explanation: The Kali River of Karnataka flows west to the Arabian Sea, so the assertion is false. The broader Deccan Plateau generally slopes east, supporting the reason. Regional relief, river outlets and tributary connections help distinguish the surrounding drainage basin geographically.
Q26. Arrange rivers from north to south: Shyok, Zanskar, Spiti and Sutlej.
[UPSC CSE Prelims (2006)]
(A) Shyok, Spiti, Zanskar, Sutlej
(B) Shyok, Zanskar, Spiti, Sutlej
(C) Zanskar, Shyok, Sutlej, Spiti
(D) Zanskar, Sutlej, Shyok, Spiti
Answer: (B) Shyok, Zanskar, Spiti, Sutlej
Explanation: Shyok lies in the northern Ladakh–Karakoram system, followed southwards by Zanskar, Spiti and Sutlej. Their courses are separated by high Himalayan ranges. Regional relief, river outlets and tributary connections help distinguish the surrounding drainage basin geographically.
Q25. Which source–river statement is incorrect?
[UPSC CSE Prelims (2006)]
(A) Mahanadi rises in Chhattisgarh
(B) Godavari rises in Maharashtra
(C) Cauvery rises in Andhra Pradesh
(D) Tapi rises in Madhya Pradesh
Answer: (C) Cauvery rises in Andhra Pradesh
Explanation: The Cauvery originates at Talakaveri in Karnataka’s Brahmagiri hills, not in Andhra Pradesh. The other source-region statements are correct. Regional relief, river outlets and tributary connections help distinguish the surrounding drainage basin geographically.
Q24. Rajghat River Valley Project is on which river?
[UPPCS Prelims (2006)]
(A) Ken
(B) Son
(C) Chambal
(D) Betwa
Answer: (D) Betwa
Explanation: Rajghat is a joint Madhya Pradesh–Uttar Pradesh project on the Betwa near Lalitpur. It provides canal irrigation and storage in Bundelkhand. Regional relief, river outlets and tributary connections help distinguish the surrounding drainage basin geographically.
Q23. Assertion: Narmada forms a delta at its mouth. Reason: It runs through a rift valley.
[UPPCS Mains (2005)]
(A) Both true, reason explains
(B) Both true, reason does not explain
(C) Assertion true, reason false
(D) Assertion false, reason true
Answer: (D) Assertion false, reason true
Explanation: Narmada normally enters the Gulf of Khambhat through an estuary, not a depositional delta. Its rift-guided course is a true geographical characteristic. Plateau slopes and underlying geological structures are especially important in determining peninsular drainage patterns.
Q22. Choose descending length order for Godavari, Mahanadi, Narmada and Tapi.
[UPSC CSE Prelims (2003)]
(A) Godavari, Mahanadi, Narmada, Tapi
(B) Godavari, Narmada, Mahanadi, Tapi
(C) Narmada, Godavari, Tapi, Mahanadi
(D) Narmada, Tapi, Godavari, Mahanadi
Answer: (B) Godavari, Narmada, Mahanadi, Tapi
Explanation: Approximate lengths are Godavari 1,465 km, Narmada 1,312 km, Mahanadi 851 km and Tapi 724 km, placing them in the second sequence. Plateau slopes and underlying geological structures are especially important in determining peninsular drainage patterns.
Q21. Match these river–tributary pairs: Ganga, Godavari, Krishna, Yamuna with Son, Manjira, Bhima, Ken.
[UPPCS Mains (2003)]
(A) Son, Ken, Manjira, Bhima
(B) Ken, Manjira, Son, Bhima
(C) Manjira, Son, Bhima, Ken
(D) Son, Manjira, Bhima, Ken
Answer: (D) Son, Manjira, Bhima, Ken
Explanation: Son joins Ganga, Manjira joins Godavari, Bhima joins Krishna and Ken joins Yamuna. The complete sequence is the fourth option. The wider drainage network links Himalayan tributaries with major alluvial floodplains and downstream deltas.
