Civil UPSC ESE Exam Solution 2021
UPSC ESE Exam Solution 2021 for Civil Engineering UPSC ESE 2021 GS Paper 1 download exam paper from telegram https://telegram.me/civil_experiences
In a groundwater field test, a tracer took 8 hours to travel between two observation wells which are 56 m apart. The difference in water table elevations in these wells was 0.70 m. The volume of the void of the aquifer is 30% of the total volume of the aquifer. What is the hydraulic conductivity of the aquifer, if the dynamic viscosity of water is 0.995 × 10-3 Ns/m2?
ANSWER= [A] 4.664 cm/s
Detailed Solution for Civil Engineering Exam
The tracer records the actual velocity of water
Vact = (56 * 100)/(8 * 60 * 60) = 60/36 cm/sec
Discharge Velocity, V = (n * Vact)
where,
n = Porosity = (Volume of voids/Total volume)
n = 0.30 (given)
V = (0.30* (7/36)) = 7/120 cm/sec
Hydraulic gradient (i) = [0.7/56] = 1.25 * 10-2
Coefficient of permeability or hydraulic
conductivity of aquifer (k) = (V/i)
k = 7/(120 * 1.25 * 10-2)
k = 14/3 cm/sec = 4.67 cm/sec
