MICROMERETICS
TOP 10 MCQ
1. Kozeny–Carman equation is used to determine the [GPAT-2023 SHIFT-II]
(a) Surface area of the powder
(b) Viscosity of a liquid
(c) Surface tension of a liquid
(d) Density of a liquid
2. Which is the correct choice of particle size measurement technique in scoring order of size [GPAT-2023 SHIFT-II]
[P] Sieve
[Q] Anderson Pipette
[R] Coulter counter
[S] Light scattering
(a) P, Q, R, S
(b) Q, S, R, P
(c) P, R, Q, S
(d) S, P, R, Q
3. If S is the solubility of small particles of radius r, is the normal solubility (i.e., of a solid consisting of fairly large particles), is the interfacial energy, M is the molecular weight of the solid, ρ is the density of the solid, R is the gas constant, T is the temperature, then which of the following equation indicates the changes in interfacial free energy that accompany the dissolution of particles of varying sizes causing the solubility of substance to increase with decreasing particle size [GPAT-2023 SHIFT-I]
(a) Log (S₀/S) = 2γM r / 2.303 RTρ
(b) Log (S₀/S) = 2γM / 2.303 RTρ r
(c) Log (S/S₀) = 2γM / 2.303 RTρ r
(d) Log (S/S₀) = 2γM r / 2.303 RTρ
4. Which of the following instrument is used to determine surface area and pore structure of pharmaceutical powders [GPAT-2021]
(a) Fisher Sub-sieve sizer
(b) Anderson apparatus
(c) Quantasorb
(d) Optical microscopy
5. One of the following apparatus is used to determine the particle size by the gravity sedimentation method [GATE-2002, GPAT-2017]
(a) Pycnometer
(b) Ostwald viscometer
(c) Andreasen apparatus
(d) Friabilator
6. If mean volume number diameter of a powdered sample is 2.41 µm, density is 3 g/cm³, the number of particles/gm will be [GPAT-2019]
(a) 5.38 × 10¹⁰
(b) 3.68 × 10¹⁰
(c) 4.55 × 10¹⁰
(d) 4.70 × 10¹⁰
7. In a free-flowing powder, the bulk density and tapped density would be close in value, therefore, the Carr index would be [GPAT-2018]
(a) Small
(b) Medium
(c) Large
(d) None of these
8. Which of the following statement is NOT true regarding bulkiness [GPAT-2019]
(a) The reciprocal of bulk density is bulkines
(b) Bulkiest substance will require container larger than required for less bulky substance
(c) Smaller particles shift between larger ones and increases bulkiness
(d) Bulkiness increases with decrease in particle size
9. The angle of repose is calculated by [GPAT-2018]
(a) tan α = Radius / Height
(b) tan α = 1 + Radius / Height
(c) tan α = 1 − Radius / Height
(d) tan α = Height / Radius
10. Free-flowing powders show a flatter cone and have [GPAT-2017]
(a) Smaller angle of repose
(b) Larger angle of repose
(c) Intermediate angle of repose
(d) None of these
ANSWER KEY
| 1-a | 2-b | 3-a | 4-c | 5-c | 6-c | 7-a | 8-c | 9-d | 10-a |
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