Which one of the following rivers is NOT the part of Indian Ganga river basin?
- (a)Punpun river
- (b)Ajoy river
- (c)Jalangi river
- (d)Jonk river
Correct — D, Jonk river. The Jonk is a tributary of the MAHANADI, rising on the Chhattisgarh-Odisha uplands and joining the Mahanadi system — so it drains the Mahanadi basin, NOT the Ganga basin. The other three all belong to the Ganga system: Punpun (Bihar), Ajoy/Ajay (Jharkhand-West Bengal) and Jalangi (West Bengal) each end up in the Ganga/Bhagirathi-Hooghly network. Since the question asks which river is NOT part of the Ganga basin, the Mahanadi tributary Jonk (d) is the answer.
- (a)Punpun river — Belongs to the Ganga basin (so not the answer) — the Punpun rises in the Chotanagpur plateau and flows through Bihar to join the Ganga a little downstream of Patna.
- (b)Ajoy river — Belongs to the Ganga basin (so not the answer) — the Ajay (Ajoy) rises in Jharkhand, flows through West Bengal and joins the Bhagirathi-Hooghly, the deltaic distributary of the Ganga.
- (c)Jalangi river — Belongs to the Ganga basin (so not the answer) — the Jalangi is a river of Nadia district, West Bengal, that carries Ganga water and joins the Bhagirathi (Hooghly), part of the Ganga delta network.
A river basin is the total area drained by a river and all its tributaries. Three of these rivers feed the Ganga system — the Punpun joins the Ganga trunk in Bihar, while the Ajay and Jalangi feed the Bhagirathi-Hooghly in the Ganga delta of West Bengal. The Jonk is different: it is a tributary of the Mahanadi, which is an independent east-flowing peninsular river that empties into the Bay of Bengal near Paradip, entirely separate from the Ganga system.
The task is to spot the ONE river that drains a different basin. If you recognise Punpun, Ajay and Jalangi as eastern-India rivers tied to the Ganga/Hooghly, the odd name out is 'Jonk'. Jonk is a lesser-known Mahanadi tributary of Chhattisgarh/Odisha — remembering that the Mahanadi basin is separate from the Ganga basin immediately gives option (d).
- Jonk river is a tributary of the Mahanadi (Chhattisgarh/Odisha) — Mahanadi basin, not Ganga basin.
- Punpun flows through Bihar and joins the Ganga near/downstream of Patna.
- Ajay (Ajoy) rises in Jharkhand and joins the Bhagirathi-Hooghly (Ganga delta) in West Bengal.
- Jalangi (Nadia, West Bengal) carries Ganga water and joins the Bhagirathi (Hooghly).
Three rivers feed the Ganga system; the Jonk drains to the Mahanadi, so it is the odd one out (answer d).
- Assuming every eastern-India river ending in the Bay of Bengal belongs to the Ganga — the Mahanadi (and its Jonk tributary) is a separate basin
- Confusing 'Jonk' with a Ganga tributary because of its unfamiliar name
UPPSC/UPSC often test 'river ↔ basin/tributary' membership — know which tributaries belong to the Ganga versus the Mahanadi/Godavari/Krishna systems, and match tributaries to their parent rivers.
In the map shown in the given figure, rivers labelled as 1, 2, 3 and 4 are respectively
- (a) Kosi, Gomati, Ghaghara and Gandak
- (b) Kosi, Ganga, Gomati and Ghaghara
- (c) Gandak, Ganga, Gomati and Ghaghara
- (d) Teesta, Gomati, Ghaghara and Kosi
Answer(a) Kosi, Gomati, Ghaghara and Gandak
Same concept — identifying rivers of the Ganga system. Kosi, Gomati, Ghaghara and Gandak are all Ganga tributaries, the very membership knowledge needed to pick the non-Ganga (Jonk) river here.
Consider the following rivers: I. Kishenganga II. Ganga III. Wainganga IV. Penganga The correct sequence of these rivers when arranged in the north-south direction is —
- (a) I, II, III, IV
- (b) II, I, III, IV
- (c) I, II, IV, III
- (d) I, III, IV, II
Answer(c) I, II, IV, III
Same underlying skill — distinguishing rivers of different systems (Ganga vs the Indus-system Kishenganga and the Godavari-system Wainganga/Penganga), i.e. knowing which river belongs to which basin.
Which one of the following (Tributary – River) is not correctly matched?
- (a) Manjra – Godavari
- (b) Hemavathi – Kaveri
- (c) Pranhita – Mahanadi
- (d) Malaprabha – Krishna
Answer(c) Pranhita – Mahanadi
Same concept — matching a tributary to its correct parent river/basin. There the false pair is 'Pranhita – Mahanadi' (Pranhita is a Godavari tributary); here the odd river is Jonk, an actual Mahanadi tributary outside the Ganga basin.
- practice — not a real PYQ
The Jonk river is a tributary of which of the following rivers?
- (a)Ganga
- (b)Mahanadi
- (c)Godavari
- (d)Narmada
Answer(b) Mahanadi — the Jonk drains the Chhattisgarh-Odisha uplands into the Mahanadi, so it belongs to the Mahanadi basin, not the Ganga basin.
- practice — not a real PYQ
Which one of the following rivers joins the Bhagirathi-Hooghly and is part of the Ganga delta system in West Bengal?
- (a)Jonk
- (b)Wainganga
- (c)Jalangi
- (d)Indravati
Answer(c) Jalangi — a Nadia (West Bengal) river that carries Ganga water and joins the Bhagirathi (Hooghly); Wainganga and Indravati belong to the Godavari system and Jonk to the Mahanadi.