Question

The principal tributary of Brahmaputra in India is_________.
a) Kosi
b) Son
c) Hooghly
d) Subansiri

Answer 1

Hint: Brahmaputra is a Himalayan river that flows through China, India and Bangladesh. It is the 15th longest river in the world.

Complete Answer: After rising in the Mansarovar region, the river enters India through Arunachal Pradesh, flows through Assam and then enters Bangladesh. The Brahmaputra receives numerous tributaries in its stretch in India.

Let us look at the options given to us.
Option A-Kosi is a transboundary river that flows through India and Nepal. It is a tributary of Ganga.
Option B- Son river originates near Amarkantak and is the second largest tributary of Ganga after Yamuna.
Option C- Hooghly is a river in West Bengal and is formed by the merger of Bhagirathi and Jalangi rivers. Hooghly is a distributary of Ganga.
Option D- Subansiri is the longest tributary of Brahmaputra. The river is 442 km long and has a basin of 32,640 square kilometers. Rising in Tibet, it flows through Arunachal Pradesh before joining Brahmaputra in Lakhimpur district of Assam. The Subansiri is an antecedent river and contributes around 8% to Brahmaputra’s flow.

Therefore the correct answer is Subansiri, option (D).

Note: Brahmaputra’s right bank tributaries include Kameng River, Manas River, Beki River, Raidak River, Jaldhaka River, Teesta River, Subansiri River. Its left bank tributaries include Nyang River, Lohit River, Dhansiri River and Kolong River.On entering Bangladesh, Brahmaputra is known as Jamuna.