4. The flow of water (mass density = 1000 kg/m3 and kinematic viscosity = 10-6 m2/s) in a commercial pipe, having equivalent roughness ks as 0.12 mm, yields an average shear stress at the pipe boundary = 600 N/m2. The value of ks/?' (?' being the thickness of laminar sub-layer) for this pipe is
Correct Answer: react with any ammonia and readily oxidisable organic matter
9. A saturated clay stratum draining both at the top and bottom undergoes 50 percent consolidation in 16 years under an applied load. If an additional drainage layer were present at the middle of the clay stratum, 50 percent consolidation would occur in
10. Water table drops by 3 m in an irrigable land of 50 hectare. If porosity and specific retention are 0.30 and 0.10 respectively, the change in storage in hectare-meter is :