Question

Consider the following measuring structures.

A. Submerged broad-crested weir

B. Free broad-crested weir

C. Free sharp-crested weir

D. Free ogee spillway

Which is the correct sequence of the discharge coefficient of these structures in increasing order?

1. B, A, C, D
2. B, A, D, C
3. A, B, D, C
4. A, B, C, D

Answer 1

Correct Answer - Option 4 : A, B, C, D

Weir:

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:

1. Sharp – crested weir
2. Broad – crested weir
3. Narrow – crested weir
4. Ogee – shaped weir

Submerged weirs have lesser coefficient of discharge compared to free weir.

For ogee spillway,

C_d = 1.19 × C_ds

C_ds = 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