Govt Exams
Power output = η × ρgQH = 0.85 × 1000 × 9.81 × 3.5 × 45 = 1312 kW approximately
In a convergent nozzle, pressure decreases and velocity increases due to Bernoulli's principle. Temperature may decrease due to pressure drop.
Hydraulic power = ρgQH = 1000 × 9.81 × 0.05 × 25 = 12.26 kW. Required power = 12.26/0.80 = 15.33 kW
Hagen-Poiseuille equation applies only to laminar flow where Re < 2300. Beyond this critical value, flow becomes transitional or turbulent.
Q = Cd × A × √(2gh) = 0.62 × 0.01 × √(2 × 9.81 × 4) = 0.0124 m³/s
By continuity equation A₁V₁ = A₂V₂. Since diameter ratio is 2:1, area ratio is 4:1, so V₂ = 1.5 × 4 = 6.0 m/s
Using Bernoulli: (P₀ - P) = ½ρV². So V = √(2 × 5500/1000) = 3.32 m/s ≈ 3.16 m/s
hf = f(L/D)(V²/2g) = 0.04 × (100/0.05) × (4/19.62) = 6.53 m
Ketchup is a pseudoplastic fluid whose viscosity changes with shear rate. Water, air, and mercury are Newtonian fluids with constant viscosity.
Shear stress τ = μ × (du/dy) = 0.8 × 100 = 80 Pa. This is a direct application of Newton's law of viscosity.