Fluid Mechanics MCQs

151. The pressure drop per unit length of pipe incurred by a fluid ‘X’ flowing through pipe is Δp. If another fluid ‘Y’ having both the specific gravity & density just double of that of fluid ‘X’, flows through the same pipe at the same flow rate/average velocity, then the pressure drop in this case will be

by
Δp
2Δp
Δp²
Δp/2
✅ The correct answer is option B.

157. A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun’s equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 x 10³ VOM + 10.94 x 10⁶ V²OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ?

by
0.2
0.5
0.7
0.8
✅ The correct answer is option C.