This question was quite popular among the candidates and their performance was on the average.  Many of those who answered the question could name the natural and artificial lakes correctly but some could not illustrate the formation of the lake properly because they could not explain the features well with suitable diagrams.

Many of the candidates who wrote on the formation of a rift valley lake were not able to properly explain it.  The expected answers include:

-           tensional forces builds up leading to the formation of faults;
-           the fault planes extend deep into the earth where they are inclined  towards one another;
-           the blocks of land on the outer side of the fault plane are pulled apart leading to a deeper penetration of the fault plane;
-           the blocks on either sides of the block rise more prominently leading to the formation of a rift valley;
-           water settles in the valley to form a rift valley lake.