Correct Answer - Option 4 : A, B, C, D
It is a low obstruction that is built across a river or canal to raise the water level, or in parallel to divert the water. The weir are widely used to measure the rate of flow.
On the basis of the shape of the crest weirs are 4 types:
- Sharp – crested weir
- Broad – crested weir
- Narrow – crested weir
- Ogee – shaped weir
Submerged weirs have lesser coefficient of discharge compared to free weir.
For ogee spillway,
Cd = 1.19 × Cds
Cds = Discharge coefficient for sharp-crested weir
Hence the correct sequence of the value of the coefficient of discharge for different weir in increasing order is as follows;
Submerged broad-crested weir < Free broad-crested weir < Free sharp-crested weir < Free ogee spillway