Top 250+ Solved Physical Pharmaceutics 2 MCQ Questions Answer
Q. In the stability of emulsion, which instability step is prevented by emulsifiers?:
a. breaking
b. coalescence
c. creaming
d. flocculation
Q. The main function of an emulsifier in the preparation of an emulsion is to:
a. develop a condensed membrane layer film
b. increase the repulsions between globules coming together
c. increase the surface free energy
d. reduce the interfacial tension
Q. An emulsifier can be regarded as superior, if its mechanism of action is based on the principle of:
a. developing solid adsorption film
b. forming monomolecular adsorption film
c. generating multimolecular adsorption film
d. increasing interfacial energy
Q. An emulsifier is considered to be ideal, if it is soluble in:
a. aqueous, oil and gas phases
b. aqueous phase only
c. both aqueous and oil phase
d. oil phase only
Q. On commercial scale, emulsions are prepared by::
a. centrifugation
b. dialysis
c. freezing
d. homogenization
Q. Microemulsion is NOT considered to be a true emulsion, because:
a. appearance is transparent
b. emulsifier is not used
c. immiscible phase is absent
d. internal phase is not spherical
Q. A variety of factors would influence the rate of creaming in an emulsion.The factor open to formulation pharmacist is to regulate:
a. density of dispersion medium
b. density of dispersed phase
c. globule size
d. volume of dispersion medium
Q. Normally preservatives are added to an emulsion. One of the following statements is true.
a. amount of the preservative added is below minimum inhibitory concentration
b. emulsifier should enhance the preservative action
c. preservatives remain in the aqueous phase
d. preservatives stay in the oil phase
Q. For the formulation of w/o emulsion, the coalescence rate of:
a. w/o has no relationship to the type of emulsion formed
b. o/w is equal to w/o coalescence rate
c. o/w is greater than w/o coalescence rate
d. w/o is greater than the o/w coalescence rate
Q. Auxiliary emulsifying agents are used to stabilize the emulsion. They act on the principle:
a. adjusting the HLB value
b. strengthening the nonpolar tails of the emulsifier ^
c. strengthening the polar heads of the emulsifier
d. thickening the continuous phase
Q. O/W emulsions normally cream .........
a. up first & down then
b. upward
c. downward
d. none of the above
Q. Microemulsions contain globules of the size about .........
a. 10 micro meter
b. 1 micro meter
c. 0.1 micrometer
d. 0.01 micrometer