The fluid property which matters for falling rain drops to acquire spherical shape is its__________________?

Related Mcqs:

1. Bernoulli’s equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli’s equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is steady. C. Fluid flow is uniform & turbulent. D. Fluid is compressible. E. Fluid is incompressible ?

   A. A, C, D
   B. B, D, E
   C. A, B, E
   D. A, D, E

2. 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

3. 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.

4. 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

5. A spherical particle is falling slow in a viscous liquid such that Reynolds number is less than 1. Which statement is correct for this situation ?

   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

6. 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__________________?

   A. Δp
   B. 2Δp
   C. Δp2
   D. Δp/2

7. In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant ?

   A. Rotational
   B. Unsteady
   C. Turbulent
   D. Non-uniform

8. 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

9. 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

10. The ratio of the wall drag to the form drag in the Stoke’s law range (for motion of spherical particles in a stationary fluid) is__________________?

    A. 0.5
    B. 1
    C. 2
    D. 0.33