Which of the following is not the tributary of river Sindhu ?

Question

UnlockIAS · Accepted Answer

Correct — option (3), Son. Read the stem carefully first: the word 'not' is printed in bold, so this is a negative question and the answer is the one river in the list that does NOT belong to the Indus system. Three of the four options are members of the Punjab five — the tributaries whose combined waters give the Punjab its name — and only the Son sits in a different drainage basin altogether. The Sindhu, or Indus, rises near Lake Mansarovar in Tibet, flows north-west through Ladakh, turns south through Pakistan and reaches the Arabian Sea. Its great left-bank tributaries are the Jhelum, the Chenab, the Ravi, the Beas and the Sutlej; these five gather one into another in the Punjab plains — the Beas joins the Sutlej, the Sutlej joins the Chenab, and the combined stream, called the Panjnad, meets the Indus. The paper prints 'Chinab' for Chenab and 'Biyas' for Beas, but both are unmistakably members of that group. The Son belongs to the Ganga system and to a completely different part of India: it rises on the Amarkantak plateau in Madhya Pradesh — the same upland that gives rise to the Narmada — flows north-east through Madhya Pradesh and across Bihar, and joins the Ganga a little upstream of Patna. It is one of the Ganga's major right-bank tributaries, and it is the only right-bank tributary of the Ganga besides the Yamuna that carries a substantial volume, because most of the Ganga's water comes from its Himalayan left-bank feeders while the peninsular right-bank streams like the Son, the Chambal-fed Yamuna system and the Damodar drain older, harder plateau country. Nothing in the Son's course brings it anywhere near the Indus basin, and the Vindhya-Satpura upland separates the two systems entirely. So the Son is the exception the question is asking for, and option (3) is the answer.

Why the other options are wrong — (a) The Chenab — printed here as 'Chinab' — is a genuine tributary of the Indus and therefore cannot be the answer to a question that asks which river is NOT one. It is the largest of the five Punjab rivers by volume, formed in Himachal Pradesh by the meeting of the Chandra and Bhaga streams in the Lahaul valley, from which it takes its older name Chandrabhaga. It flows through Jammu and Kashmir into Pakistan, where it receives the Ravi and the Sutlej before the combined Panjnad joins the Indus. On a negative-stem question a correct fact is exactly what has to be rejected.  (b) The Beas — printed here as 'Biyas' — is also a true Indus tributary, so it too has to be rejected on a question asking for the exception. It rises near the Rohtang Pass in Himachal Pradesh, flows past Mandi and Kullu into the Punjab plains, and joins the Sutlej at Harike, from where its water reaches the Indus through the Sutlej and the Panjnad. Of all the Punjab rivers it is the only one whose entire course lies within India, which is a distinguishing fact worth holding but does not remove it from the Indus system.  (d) The Ravi is the third of the three Indus tributaries offered here and is equally disqualified from being the answer. It rises in the Kullu hills of Himachal Pradesh, flows past Chamba and along part of the India-Pakistan boundary before entering Pakistan and joining the Chenab. It is the smallest of the Punjab rivers by discharge, which sometimes makes candidates hesitate over it, but size has nothing to do with membership of a drainage basin — the Ravi drains into the Indus and so belongs to the Indus system.

Concept: India's northern rivers fall into three great Himalayan systems — the Indus, the Ganga and the Brahmaputra — and the boundaries between them are watersheds, not political lines. The Indus system drains the western end: the main stream rises in Tibet near Mansarovar, and its five left-bank tributaries, the Jhelum, Chenab, Ravi, Beas and Sutlej, rise in the western Himalaya and the Himachal ranges and converge stepwise in the Punjab plains before entering the Indus as one river, the Panjnad. The Ganga system drains the centre and receives two very different classes of tributary: the Himalayan left-bank rivers such as the Ghaghara, Gandak and Kosi, which are perennial and snow-fed, and the peninsular right-bank rivers such as the Yamuna's Chambal and Betwa feeders, the Son and the Damodar, which rise on the old plateaus of central India and are far more seasonal. The Son is the clearest example of that second class: it rises on the Amarkantak plateau, the same water-parting from which the Narmada flows west, and its water reaches the Bay of Bengal, not the Arabian Sea.

State PCS 2024 Q23 — Geography PYQ with Answer

State PCS 2024 Q23 — Geography PYQ with Answer