### Chapter 4: Micromeritics MCQs with Answer

1. One micrometer is equal to:
a. 10-6 centimeter
b. 10-3 centimeter
c. 10-6 meter
d. 10-3 meter
Ans:c

2. Which of the following properties of a particle significantly affects the physical, chemical and biological properties of the drug?
a. density
b. sedimentation
c. size
d. surface area
Ans:d

3. It is difficult to express the size of particles in a meaningful diameter.
a. irregular in shape
b. irregular surface
c. spherical shape
d. uniform in size
Ans:a

4. The type of a particle diameter obtained largely depends on:
a. method by which it is determined
b. nature of the powder
c. procedure by which it is calculated
d. way it is defined and described
Ans:a

5. When cumulative percent frequency on a probability scale is plotted against logarithm of the particle size, 50 percent on the probability scale gives the powder particle diameter of:
a. arithmetic mean
b. arithmetic mode
c. geometric mean
d. harmonic mean
Ans:c

6. Which one of these distributions is more important in the design of dosage forms?
a. Gaussian
b. normal
c. number
d. weight
Ans:d

7. In the formulation development of emulsions and suspensions, what type of diameter is important?
a. length number. b. projected
c. sieve d. stokes
Ans:d

8. Sieving method is used for size distribution analysis of powder. The disadvantage of this method is:
a. agglomerates can be identified
b. attrition of powder is possible
c. large number of sieves are required
d. tedious and time consuming
Ans:b

9. While using sedimentation method for size analysis, addition of a deflocculating agent to a suspension is necessary in order to:
a. accelerate the process of sedimentation
b. make the particles spherical
c. prevent the aggregation
d. satisfy Reynolds number
Ans:c

10. Stokes’ law cannot be used, if Reynolds number is more than:
a. 0.2
b. 1.8
c. 9.0
d. 18.0
Ans:a

11. Andreasen apparatus consists of:
a. balance
b. electrodes
c. hydrometer
d. pipette
Ans:c

12. When coulter-counter apparatus is employed for powder analysis, the following criterion is important:
a. dispersion medium should be colored
b. dispersion medium should be conducting
c. suspended particles should be charged
d. suspended particles should be spherical
Ans:b

13. In coulter-counter, as the particles travel through the orifice, the event that occurs is:
a. conductance between the electrodes increases
b. electronic scanners produce photographs for volume measurement
c. resistance between the electrodes increases
d. sedimentation increases
Ans:c

14. Fisher subsieve sizer is used to determine the surface area of the powder. The surface area is measured based on the change in:
a. light transmission of gas that reaches the detector
b. pressure across the compacted powder
c. thermal conductivity of gas across the powdered pack
d. weight of powder when air is passed through the powdered pack
Ans:d

15. High repose angle of the granules indicated:
a. bulk density of the granules
b. porosity of the granules
c. roughness of the granule surface
d. smoothness of the granule surface
Ans:c

16. The true density of talc is 2.7 g/cc, the bulk density (g/cc) of talc will be:
a. equal to 2.7
b. greater than 2.7
c. less than 2.7
d. unrelated
Ans:c

17. The angle of repose values are utilized to:
a. measure the movement of granules from hopper to the table of tabletting/capsule machine
b. select proper containers for capsules of a given mass of powders
c. study the absorption of drugs
d. understand dissolution of medicament
Ans: a

18. The term ‘light’ as applied to pharmaceutical powders means:
a. low bulk density
b. low granule density
c. low true density
d. slightly coloured
Ans:b

19. The type of particle diameter that is obtained by microscope method of evaluation is:
a. projected
b. stokes’
c. volume
d. volume-surface
Ans:a

20. Porosity of a porous powder is defined as:
a. bulk volume/void volume
b. void volume/bulk volume
c. void volume/true volume
d. true volume/bulk volume
Ans:b

21. Which equation is used to convert number distribution to weight distribution
a. Noyes whitney equation
b. Hatch Choate equation
c. Henderson Hasselbalch equation
d. Higuchi equation
Ans:b

22. Coulter counter is used to determine
a. Particle volume
b. Particle Number
c. Particle interaction
d. Viscosity
Ans:a

23. The ratio of void volume to bulk volume is known as
a. Bulk density
b. Tapped density
c. Porosity
d. Granule volume
Ans:a

24. If Carr’s compressibility index value is in between 26 to 31, then flow will be
a. Poor
b. Excellent
c. Passable
d. Very, very poor
Ans:a

25. Hausner Ratio is
a. Tapped density / Bulk density
b. Bulk density / Tapped density
c. bulk volume / void volume
d. void volume / bulk volume
Ans:a

26. The powder having low bulk density or large bulk volume is known as
a. Light powder
b. Heavy powder
c. Bulk powder
d. Granular powder
Ans:a

27. The term Micromeritics was given by
a. J.M. Dalla Valle
b. James Kelvin
c. William Procter
Ans:a

28. Andreasen pipette is widely used method to determine particle size distribution by
a. Microscopy method
b. sedimentation method
c. Sieving method
d. All of the above
Ans:b

29. Porosity is expressed in
a. Percentage
b. Millimeter
c. Gram/Millimeter
d. Newton
Ans:a

30. Helium Pycnometer is used to determine
a. Size
b. True density
c. Sedimentation rate
d. Surface area
Ans:b

31. The porosity of powder is equal to
a. Ratio of void volume to bulk volume.
b. Sum of void volume to bulk volume
c. Product of void volume to bulk volume
d. Void volume only
Ans:a

32. The distance between two tangents on opposite sides of the particle parallel to some fixed direction.
a. Feret’s diameter
b. Martin diameter
c. Projected diameter
d. Stoke’s diameter
Ans:a

33. Andreason apparatus consist of
a. Reference electrode
b. Pipette
c. Glass electrode
d. Hydrogen electrode
Ans:b

34. For a sphere, value of αs/αv equals to
a. 6
c.9
b.1.8
d.18
Ans:a

35. The physical, chemical, and pharmacologic properties of a drug are directly affected by……
(a) Size
(b) Surface area
(c) Both of the above
(d) None of the above
Ans:c

36………….is the science and technology of small particles.
(a) Micromeritics
(b) Microscopy
(c) Rheology
(d) None of the above
Ans:a

37. The unit of particle size used is in…………
(a) Kilometer (km)
(b) Centimeter (Cm)
(c) Millimeter (mm)
(d) Micrometer (µm)
Ans:d

38. 1 micrometer (µm) is equal to
(a) 10-5 m
(b) 10-6 m
(c) 10-7 m
(d) 10-8 m
Ans:b

39. Particle size with diameter of 0.5-1.0 Micrometers (µm) is useful for……..
(a) Emulsions
(b) Suspensions
(c) Both of the above
(d) None of the above
Ans:c

40. The size of a sphere is freely stated in terms of its………….
(a) Area
(b) Diameter
(d) Volume
Ans:b

41 ……is the diameter of a sphere having, the same observed area as the particle when viewed normal to its most stable plane.
(a) The surface diameter (ds)
(b) The projected diameter (dp)
(c) The volume diameter (dv)
(d) The Stokes diameter (dst)
Ans:b

42 …. is the number of particles per unit weight.
(a) Particle volume
(b) Particle number
(c) Particle mean
(d) Particle weight
Ans:b

43 …….technique is utilized for estimation of surface diameter ds.
(a) Air permeability
(b) Vacuum
(c) Filtration
(d) Weighing
Ans:a

44. The ratio of the void volume to the bulk volume of the packing is called as the………………..
(a) Tap density
(b) Bulk density
(c) Followability
(d) Porosity
Ans:d

Subject:- Physical pharmaceutics 2