Related Mcqs:

1. A gas (density = 1.5 kg/m3, viscosity = 2 × 10‒5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5 kg/m3and viscosity of 3 × 10‒5kg/m.s flowing at 3 m/s will be________________?

   A. 8400 Pa/m
   B. 12600 Pa/m
   C. 18900 Pa/m
   D. 16800 Pa/m

2. For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit length of bed depends upon the sphere diameter as_________________?

   A. d
   B. d2
   C. d4
   D. d̅ 2

3. For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is________________?

   A. More
   B. Less
   C. Equal
   D. Independent of porosity

4. 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 × 103 VOM + 10.94 × 106 V2 OM (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 ?

   A. 0.2
   B. 0.5
   C. 0.7
   D. 0.8

5. Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is________________?

   A. 90
   B. 60
   C. 45
   D. 30

6. A Newtonian liquid (ρ = density, μ = viscosity) is flowing with velocity „v‟ in a tube of diameter ‘D’. Let Δp be the pressure drop across the length ‘L’. For a laminar flow, Δp is proportional to_________________?

   A. Lρv2/D
   B. LμV/D2
   C. Dρv2/L
   D. μV/L

7. 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 × 103 VOM + 10.94 × 106 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is_________________?

   A. 12 mm/s
   B. 16 mm/s
   C. 24 mm/s
   D. 28 mm/s

8. Applying a pressure drop across a capillary results in a volumetric flow rate ‘Q’ under laminar flow conditions. The flow rate for the same pressure drop, in a capillary of the same length but half the radius is____________________?

   A. Q/2
   B. Q/4
   C. Q/8
   D. Q/16

9. Pressure drop in a packed bed for laminar flow is given by the ______________ equation?

   A. Kozeny-Carman
   B. Blake-Plummer
   C. Leva’s
   D. Fanning friction factor

10. For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) ?

    A. μ
    B. 1/μ
    C. √μ
    D. 1/√μ