Geography Quiz: Himalayas and the Northern Plains

The Himadri is the innermost and northernmost of the three parallel Himalayan ranges, with an average height of about 6,000 metres.

Duns are flat-floored longitudinal valleys formed where rivers coming out of the Lesser Himalaya were held up behind the rising Shiwalik and filled the depression with gravel and silt.

Karewas are thick beds of glacial clay, silt and other lake sediments laid down in the Kashmir valley, which lies between the Pir Panjal and the Greater Himalaya.

The Bhabar is a narrow belt about 8 to 16 kilometres wide, laid along the foot of the Shiwalik range, where the rivers leaving the hills drop their coarsest load.

Bhangar is the older alluvial deposit of the Northern Plains. It forms terraces that stand above the present flood level, so fresh silt no longer reaches it, and long leaching has left calcareous concretions called kankar in its profile.

Nathu La lies in eastern Sikkim on the old trade route from Gangtok to Lhasa and is one of the passes on India's border with the Tibet region of China; Jelep La, also in Sikkim, is the other.

Kanchenjunga rises to 8,586 metres on the Sikkim-Nepal border and is the highest peak in India's undisputed territory, as well as the third highest in the world after Everest and K2.

The Himalayas were raised when the northward-moving Indian plate collided with the Eurasian plate and the sediments of the shallow Tethys Sea between them were compressed into great folds and thrust upward.

The Pir Panjal is the longest and most important range of the Lesser or Himachal Himalaya, running from the Jhelum through Jammu and Kashmir towards Himachal Pradesh and separating the Kashmir valley from the Jammu plains.

Majuli lies in the Brahmaputra in Assam and is counted the largest river island in the world. The Brahmaputra carries an enormous load of silt from a young, rapidly eroding basin, and because its channel is braided and shifts often, it has built large islands and sandbars called chars.

The Purvanchal or Eastern Hills are the southward continuation of the Himalayas beyond the eastern bend of the Brahmaputra, and they are made up of the Patkai Bum, the Naga Hills, the Manipur Hills and the Mizo or Lushai Hills.

Doab, from the Persian words for two and water, is the name for the tract of land between two rivers.