Physical Pharmacy (Micromeritics)

The sieving method is used for the size distribution analysis of powder. The disadvantage of this method is:

• 
  agglomerates can be identified

• attrition of powder is possible

• large number of sieves are required

• tedious and time consuming

When coulter-counter apparatus is employed for powder analysis, the following criterion is important:

• dispersion medium should be colored

• dispersion medium should be conducting

• suspended particles should be charged

• suspended particles should be spherical

In coulter-counter, as the particles travel through the orifice, the event that occurs is:

• conductance between the electrodes increases

• electronic scanners produce photographs for volume measurement

• resistance between the electrodes increases

• sedimentation increases

The term Micromeritics was given by

• J.M. Dalla Valle

• James Kelvin

• William Procter

• Mahadeva Lai Schroff

Andreasen pipette is widely used method to determine particle size distribution by

• Microscopy method

• sedimentation method

• Sieving method

• Conduction method

The particle size range for ‘free flowing particles’ is

• 10-100um

• 75-250um

• 500-1000um

• 250-2000um

Average granular size range is approximately

• 10-50um

• 50-100um

• 150-1000um

• 1000-3000um

The International Standards organization (ISO) sets a lowest sieve diameter of

• 45 µm

• 50 µm

• 100 µm

• 500 µm

Percentage of void space in a porous media is called

• Bulkiness

• Porosity

• Bulk volume

• Stroke's space

A precise and accurate method for particle size determination is

• Sieving

• Andreasen sedimentation method

• Coulter counter method

• Optical microscopy