It enters India in Arunachal Pradesh through a wide valley.
Explanation
The Brahmaputra river system is one of the largest in the world, originating from the Chemayungdung glacier near the Mansarovar lake in Tibet. Its geographical course involves distinct characteristics as it traverses through Tibet, India, and Bangladesh.
Statement-wise Analysis
- Statement It is slightly longer than the Indus. is Correct: The total length of the Brahmaputra is approximately 2,900 km (some sources cite up to 3,848 km depending on the tributary measured), whereas the Indus is approximately 2,880 km long. Therefore, the Brahmaputra is slightly longer than the Indus.
- Statement Most of its course lies outside India. is Correct: A significant portion of the Brahmaputra's course lies in Tibet (where it is known as the Yarlung Tsangpo), flowing eastwards before entering India. Consequently, most of its length is situated outside Indian territory.
- Statement It flows eastwards parallel to the Himalayas. is Correct: In Tibet, the river flows eastwards, running parallel to the Himalayan mountain range to its south.
- Statement It enters India in Arunachal Pradesh through a wide valley. is Incorrect: On reaching the mountain peak of Namcha Barwa (7,782 m), the river takes a sharp 'U' turn and enters India in Arunachal Pradesh through a deep gorge (known as the Dihang Gorge), not a wide valley. The terrain here is rugged and precipitous.
Key Takeaway: The Brahmaputra enters India by cutting a deep gorge near Namcha Barwa after taking a syntaxial bend, distinguishing its entry from that of a river flowing through a wide valley.