NDA (II) 2016 General Ability Test · Question 58 of 150

Correct — C, Narmada : Amaravati is the pair that does not match. The Amaravati is a tributary of the Cauvery, not of the Narmada: it rises in the Anaimalai hills of the Western Ghats and joins the Cauvery at Karur in Tamil Nadu, a thousand kilometres and a whole drainage system away from the Narmada. There is also a structural reason why the Narmada could not have such a tributary. It runs west along a rift valley wedged between the Vindhya range to its north and the Satpura range to its south, so its basin is a long narrow trough and its tributaries are short streams coming down off those two walls — the Tawa, the largest of them, and the Burhner, Banjar, Sher, Shakkar, Hiran and Orsang. Nothing from peninsular Tamil Nadu can drain into it. NDA itself confirmed the Amaravati's parentage in 2018, when it listed the river among the genuine tributaries of the Cauvery.

• (a)Godavari : Wainganga — Correctly matched, so it is not the answer. The Wainganga flows south through eastern Maharashtra, joins the Wardha to form the Pranhita, and the Pranhita is the Godavari's largest tributary — so the Wainganga is squarely in the Godavari system.
• (b)Cauvery : Bhavani — Correctly matched. The Bhavani is one of the Cauvery's principal tributaries in Tamil Nadu, dammed at Bhavanisagar and meeting the main river at Bhavani town.
• (d)Krishna : Bhima — Correctly matched. The Bhima rises in the Western Ghats near Bhimashankar, flows south-east across Maharashtra and Karnataka, and is the Krishna's largest left-bank tributary.

Peninsular India's drainage splits into two unequal halves. Most of the plateau tilts east, so the Godavari, Krishna and Cauvery run to the Bay of Bengal with long, branching tributary systems. Only a few large rivers run west, and the Narmada and Tapi are the important ones; both occupy rift valleys, flow through narrow troughs, build no deltas and gather only short tributaries.

A not-correctly-matched item is quickest to solve by elimination rather than by hunting for the wrong pair directly. Confirm the three you are sure of and the fourth is the answer. If a river name is genuinely unfamiliar, fall back on geography — ask whether the two rivers could plausibly meet at all. The Amaravati is a Tamil Nadu river of the far south; the Narmada is a central Indian river flowing west to the Gulf of Khambhat. A confusion worth guarding against is the town of Amaravati on the Krishna in Andhra Pradesh and the city of Amravati in Maharashtra, neither of which is this river.

• The Amaravati rises in the Anaimalai hills and joins the Cauvery at Karur in Tamil Nadu.
• The Narmada flows west through a rift valley between the Vindhya and Satpura ranges; its largest tributary is the Tawa.
• The Wainganga joins the Wardha to form the Pranhita, which is the Godavari's largest tributary.
• The Bhima is the Krishna's principal left-bank tributary, and the Bhavani is a chief tributary of the Cauvery.

• Mixing the Amaravati river of Tamil Nadu with the town of Amaravati on the Krishna or the city of Amravati in Maharashtra.
• Forgetting that the Wainganga reaches the Godavari indirectly, through the Wardha and the Pranhita.

River-and-tributary pairing is one of the most repeated NDA GAT formats, asked as 'not correctly matched' at least once in most sessions, so learn each major river with three named tributaries.

• practice — not a real PYQ

  The largest tributary of the Narmada is the

  • (a)Tawa
  • (b)Bhavani
  • (c)Wainganga
  • (d)Amaravati

  Answer(a) Tawa — it joins the Narmada from the south, off the Satpura slopes.

• practice — not a real PYQ

  The Wainganga and the Wardha unite to form which river?

  • (a)Indravati
  • (b)Pranhita
  • (c)Manjra
  • (d)Penganga

  Answer(b) Pranhita — and the Pranhita is the Godavari's largest tributary.