UPSC Prelims Marathon Quiz

• Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves.

Exp)

• The Peninsular drainage system is older than the Himalayan one. This is evident from the broad, largely-graded shallow valleys, and the maturity of the rivers.

• Peninsular India is an ancient landmass. Therefore, the streams flowing through this region are in their old stage. They have almost attained their base level of erosion. Their capacity to erode valleys vertically has almost come to a negligible stage. Now, these streams are eroding their sides at a slow pace. This is resulting in the broadening of their valleys. Consequently, during flood, their waters spread over a large area.

• Steep-sided "V-shaped' valleys, waterfalls, and rapids are characteristic features of Young rivers that are absent in the case of Peninsular rivers.

• Peninsular rivers are characterized by fixed course, absence of meanders and non-perennial flow of water. The Narmada and the Tapi which flow through the rift valley are, however, exceptions.

Exp) The correct sequence(North to South direction) is:

1. Narmada

2. Tapi

3. Godavari

4. Krishna

5. Penneru

6. Palar

7. Kaveri

8. Periyar

• Option (a) is correct. The telegraph poles in the deserts are protected by a covering of metal for a foot or two above the ground to increase their resistance against abrasion only.

• Wind abrasion is a natural form of sandblasting. Wind abrasion is the process of the wearing away of a solid object due to the impact of particles carried by the wind. The wind picks up particles and moves them. When the particles collide with a solid object, the impact causes small pieces of the object to break off. This can cause the object being hit with particles to become smooth or worn. In deserts, wind abrasion shapes the rocks and boulders. In areas where strong winds consistently pick up sand and carry it, rocks and boulders in the wind's path can be impacted by wind abrasion, including the telegraph poles.