A. Inertial and drag forces are important
B. Drag, gravitational and buoyancy forces are important
C. Drag force and gravitational forces are important
D. None of the above
Related Mcqs:
- The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke’s law range is proportional to the_____________________?
A. Inverse of fluid viscosity
B. Square of particle size
C. Difference in the densities of the particle & fluid
D. All A., B. and C. - In the Newton’s law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is ______________ the fluid viscosity?
A. Directly proportional to
B. Inversely proportional to
C. Inversely proportional to the square root of
D. Independent of - In Newton’s law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the ______________ of its diameter?
A. Inverse
B. Square root
C. Second power
D. First power - The fluid property which matters for falling rain drops to acquire spherical shape is its__________________?
A. Pressure
B. Height of descend
C. Viscosity
D. Surface tension - Stoke’s law is valid, when the particle Reynolds number is ______________________?
A. < 1
B. > 1
C. < 5
D. None of these - Creeping flow around a sphere is defined, when particle Reynolds number is___________________?
A. < 2100
B. < 0.1
C. > 2.5
D. < 500 - In Newton’s law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is___________________?
A. 0.44
B. 0.044
C. 4.4
D. 44 - Hydraulic mean radius for flow through packed bed of spherical particle of size, ‘Dp, with porosity ‘ε’ is________________?
A. (Dp/6) (ε/1- ε)
B. (Dp/6) (1- ε/ε)
C. ⅔Dp (1- ε/ε)
D. ⅔Dp (ε/1- ε) - 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 - 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
