This was the most unpopular question attempted by the candidates and their  performance was very poor.

The description of the mode of formation of a deflation hollow is as outlined below:
-    deflation involves blowing away of loose rock wastes while abrasion involves hauling rocks against rock surfaces
-    deflation involves rolling loose rock materials along the ground where as abrasion, involves polishing, scratching and wearing away of rock surfaces.
-    deflation usually results in lowering of land surfaces while abrasion is most effective at the base of rocks
-    deflation is associated with winds while abrasion is associated with winds, water, and waves
-    deflation produces land forms such as deflation hollows and oasis, while abrasion produces land forms such as rock pedestal, zeugens, yardangs, etc
-    abrasion occurs every where while deflation occurs only in arid and semi-arid regions.

The mode of formation of deflation hollow is:
-    it is a feature of arid region
-    a product of wind deflation
-    a basin or saucer-shaped desert landform
-    wind exerts frictional force on loose rocks particles on the surface
-    involves the lifting of loose materials from the ground
-    it also involves scooping away of loose sandy materials
-    the loose materials lifted are blown away
-    this action consequently lowers the land surface
-    wind eddies help to deepen and enlarge the hollows particularly in soft rock zones

-    the enlarged hollows are called depressions or deflation hollows
-    they vary in size from some few metres to several kilometres
-    the depressions may reach water table to produce oasis or swamps
-    e.g. Faiyum in Egypt,  Quattarra in Egypt, Baharia in Egypt, Farafra in Egypt, Dakhla in Egypt, Wyoming in USA.