Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity ?

Related Mcqs:

1. Sphericity for a non-spherical particle is given by (where, V and S are volume and surface area respectively of one particle. and, D = equivalent diameter of particle)?

   A. 6.V/D.S
   B. V/6D.S
   C. D.S/V
   D. V/D.S

2. If dp is the equivalent diameter of a non-spherical particle, Vp its volume and sp its surface area, then its sphericity is φs is defined by________________?

   A. φs = 6 Vp/dpsp
   B. φs = Vp/dpsp
   C. φs = 6 dpSp/Vp
   D. φs = dpSp/Vp

3. The specific surface of spherical particles is proportional to (where, Dp = diameter of particle)?

   A. D2
   B. Dp
   C. 1/Dp
   D. 1/D2p

4. The specific surface of spherical particles is given by (where D and ρ are diameter and density of particle) ?

   A. 6/D.ρ
   B. 2/D.ρ
   C. 4/D.ρ
   D. 12/D.ρ

5. The sphericity of a solid particle of cubical shape is ___________________?

   A. π
   B. (π/6)1/3
   C. (π/6)1/2
   D. π/3

6. Sphericity of a cubical particle, when its equivalent diameter is taken as the height of the cube, is ________________ ?

   A. 0.5
   B. 1
   C. √2
   D. √3

7. According to Bond crushing law, the work required to form particle of size ‘D’ from very large feed is (where (S/V)p and (S/V)f are surface to volume ratio of the product and feed respectively) ?

   A. (S/V)p
   B. √(S/V)p
   C. (S/V)2p
   D. (S/V)f

8. For a non-spherical particle, the sphericity__________________?

   A. Is defined as the ratio of surface area of a sphere having the same volume as the particle to the
   actual surface area of the particle
   B. Has the dimension of length
   C. Is always less than 1
   D. Is the ratio of volume of a sphere having the same surface area as the particle to the actual
   volume of the particle

9. A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is_________________?

   A. 0.90 μm/s
   B. 1 μm/s
   C. 22.1 μm/s
   D. 0.02 μm/s

10. In a grinding operation, the limiting particle size is the size of the _______________ particle in the sample?

    A. Smallest
    B. Largest
    C. Either A. or B.
    D. Neither A. nor B.