GENERAL KNOWLEDGE

Detailed explanation-1: -A dam is a structure built across a stream or river to hold water back. Dams can be used to store water, control flooding, and generate electricity.

Detailed explanation-2: -It must be strong, as floods will wash over its crest. Over time, sand accumulates in layers behind the dam, which helps store water and, most importantly, prevent evaporation. The stored water can be extracted with a well, through the dam body, or by means of a drain pipe.

Detailed explanation-3: -Dams have gates just as barrages do, but the difference is that dams have the gates and sluices at the top to prevent flooding and spillage. In barrages, there are gates from the top down to the bed of the river. This allows for a greater capacity of storage and controlling the flow of water.

Detailed explanation-4: -A dam is usually constructed across a river to create a reservoir in the valley behind by storing the water that flows into it naturally. Sometimes, they are built across dry valleys, or valleys with small streams, to create a storage area for water that is transported from elsewhere.