A. 6/D.ρ
B. 2/D.ρ
C. 4/D.ρ
D. 12/D.ρ
Related Mcqs:
- 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 - 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 ?
A. Sphere
B. Cube
C. Cylinder (L/D = 1)
D. Raschig rings - The specific surface of spherical particles is proportional to (where, Dp = diameter of particle)?
A. D2
B. Dp
C. 1/Dp
D. 1/D2p - Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) ?
A. m/ρ . Vp
B. m . ρ/Vp
C. m . Vp/ρ
D. Vp/m . ρ - 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 - Equivalent diameter of a particle is the diameter of the sphere having the same __________________?
A. Ratio of surface to volume as the actual volume
B. Ratio of volume to surface as the particle
C. Volume as the particle
D. None of these - 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 - 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 - Velocity of a small particle of diameter ‘Dp’ at a distance ‘r’ from the rotational axis of a cyclone rotating at an angular speed ‘ω’ is given by (the other symbols are as per standard notation) ?
A. [(DP/18). (ρs – ρ/μ)] ω2r
B. [(DP2/18). (ρs – ρ/μ)] ω2r
C. [(DP/18). (ρs – ρ/μ)] ω2r2
D. [(DP2/18). (ρs – ρ/μ)] ω2r - ______________ mean diameter of particles is given by Σ (xi/Dpi ⃗)?
A. Mass
B. Volume
C. Arithmetic
D. Volume surface
