Question

According to Darcy's law, the formula for the amount of water to be discharged from the soil is- (while Q = water content, K = permeability coefficient, i - fluid gradient and A = longitudinal area).
1. Q = Ki / A
2. Q = KA i
3. Q = Ai / K
4. Q = KA / i

Answer 1

Correct Answer - Option 2 : Q = KA i

Explanation:

Darcy's Law:

(i) The flow of free water through soil is governed by darcy's law. Dracy established that the flow occuring per unit time is directly proportional to the head causing flow and the area of cross section of the soil sample but is inversely proportional to the length of the sample, i.e.

\(q \propto \frac{{Δ h}}{L}.A\)

⇒ \(q = k.\frac{{Δ h}}{L}.A = k.i.A\)

Δh = head causing flow

i = Δh/L = Hydraulic gradient

k = Coeffiicient of permeability of soil

A = Area of cross-section.