Which one of the following is a tributary of the Brahmaputra River?

Correct — D, Manas. The Manas rises in Bhutan, where it is the Drangme Chhu, cuts south through the Himalayan foothills into Assam and joins the Brahmaputra near Jogighopa. It is one of the Brahmaputra's major right-bank tributaries, alongside the Subansiri, the Kameng and the Sankosh, and it gives its name to Manas National Park on the Assam-Bhutan border.

• (a)Ghaggar — The Ghaggar never reaches the sea at all. It is an inland-drainage river of Haryana and Rajasthan that dries out in the Thar, and it is often linked with the ancient Sarasvati.
• (b)Mahi — The Mahi is a west-flowing peninsular river that crosses Madhya Pradesh, Rajasthan and Gujarat to reach the Gulf of Khambhat — the wrong side of the country entirely.
• (c)Kosi — The Kosi is a tributary of the Ganga, joining it in Bihar. Its habit of shifting course earned it the name 'sorrow of Bihar', but it never meets the Brahmaputra.

The Brahmaputra collects almost all its Indian water from the mountains on either side of the Assam valley. Its right-bank tributaries come down from the Eastern Himalaya and Bhutan — Subansiri, Kameng, Manas, Sankosh — while the left bank takes the Burhi Dihing, the Dhansiri and streams off the Patkai and Naga hills.

This item is really a three-way elimination on drainage basins. Sort the options by where the water ends up: Ghaggar ends nowhere, Mahi ends in the Arabian Sea, Kosi ends in the Ganga. Only one is left. It also pays to note that several Indian rivers share names across basins, so anchoring each name to a protected area or a state helps — Manas to Manas National Park in Assam, Kosi to the Bihar plains.

• The Manas rises in Bhutan as the Drangme Chhu and joins the Brahmaputra in western Assam.
• Manas National Park, a tiger reserve and World Heritage Site, lies on the river along the Bhutan border.
• The Brahmaputra's other main right-bank tributaries are the Subansiri, the Kameng and the Sankosh.
• The Subansiri is an antecedent river, older than the mountains it cuts through.
• The Ghaggar is a river of inland drainage that is lost in the desert of Rajasthan.

• Assuming any Himalayan-sounding river must feed the Brahmaputra.
• Confusing the Manas with the Mahanadi or the Manjira.

A single-name tributary item, or a matching list pairing tributaries with the main river they join.

• practice — not a real PYQ

  Which one of the following rivers does not drain into the sea?

  • (a)Mahi
  • (b)Ghaggar
  • (c)Subarnarekha
  • (d)Periyar

  Answer(b) Ghaggar — it is an inland-drainage river that dies out in the Thar desert.

• practice — not a real PYQ

  The Manas River flows into India from

  • (a)Nepal
  • (b)Bhutan
  • (c)Myanmar
  • (d)China

  Answer(b) Bhutan — it rises there as the Drangme Chhu before entering Assam.