Join 60,000+ competitive exam aspirants
For a flow net Nf = 5 and Nd = 20, the shape factor is
0.5
80
5
0.25
0.25
Given: Number of flow channels NfтАЛ = 5, Number of potential drops NdтАЛ = 20
Number of flow channels NfтАЛ = 5, Number of potential drops NdтАЛ = 20
S=NdтАЛNfтАЛтАЛ
Identify the given parameters
We are given the number of flow channels (NfтАЛ) as 5 and the number of equipotential drops (NdтАЛ) as 20.
NfтАЛ=5,NdтАЛ=20
Apply the shape factor formula
The shape factor (S) of a flow net is defined as the ratio of the number of flow channels to the number of equipotential drops.
S=NdтАЛNfтАЛтАЛ
Calculate the result
Substituting the given values into the formula: S=205тАЛ=0.25.
S=0.25
D is correct because the shape factor is calculated as the ratio of flow channels to equipotential drops, yielding 0.25.
The shape factor is directly used in Darcy's Law for seepage discharge calculation: q=kHNdтАЛNfтАЛтАЛ, where k is the coefficient of permeability and H is the total hydraulic head.