1. _____are formed when two or more than two gases or miscible liquids are mixed.
a) Negative mixture
b) Positive mixtures
c) Neutral mixtures
d) Solid mixtures
Answer
Answer: b [Reason:] These types of mixtures are formed when two or more than two gases or miscible liquids are mixed together by means of diffusion process.
2. ____ are formed when insoluble solids are mixed with a vehicle to form a suspension.
a) Negative mixture
b) Positive mixtures
c) Neutral mixtures
d) Solid mixtures
Answer
Answer: a [Reason:] These types of mixtures are formed when insoluble solids are mixed with a vehicle to form a suspension or when two immiscible liquids are mixed to form an emulsion.
3. _____ are static in their behavior.
a) Negative mixture
b) Positive mixtures
c) Neutral mixtures
d) Solid mixtures
Answer
Answer: c [Reason:] The components of such products do not have any tendency to mix spontaneously but once mixed, they do not separate out easily.
4. When during convective mixing, transfer of groups of particles in bulk take place is called as ____
a) Convective mixing
b) Diffusive mixing
c) Shear mixing
d) Particulate mixing
Answer
Answer: a [Reason:] During convective mixing transfer of groups of particles in bulk take place from one part of powder bed to another. Convective mixing is referred to as macromixing.
5. When, shear forces are created within the mass of the material this is called ____
a) Convective mixing
b) Diffusive mixing
c) Shear mixing
d) Particulate mixing
Answer
Answer: c [Reason:] During shear mixing, shear forces are created within the mass of the material by using agitator arm or a blast of air.
6. When, the materials are tilted so that the gravitational forces cause the upper layers to slip such mixing is called as ______
a) Convective mixing
b) Diffusive mixing
c) Shear mixing
d) Particulate mixing
Answer
Answer: b [Reason:] When the materials are tilted so that the gravitational forces cause the upper layers to slip, Diffusion is also sometimes referred to as micro mixing.
7. The movement of a relatively large portion of the material being mixed from one location in the system to another constitutes _____
a) Bulk transport
b) Laminar mixing
c) Turbulent mixing
d) Transition mixing
Answer
Answer: a [Reason:] A simple circulation of material in a mixer may not result in efficient mixing, for transport to be effective it must result in a rearrangement of the portions to be mixed.
8. ____ is a direct result of turbulent fluid flow.
a) Bulk transport
b) Laminar mixing
c) Turbulent mixing
d) Transition mixing
Answer
Answer: c [Reason:] The phenomenon of turbulent mixing is a direct result of turbulent fluid flow, which is characterized by a random fluctuation of the fluid velocity at any given point with in the system.
9. ______ is frequently encountered when highly viscous liquids are being processed.
a) Bulk transport
b) Laminar mixing
c) Turbulent mixing
d) Transition mixing
Answer
Answer: b [Reason:] It can also occur if stirring is relatively gentle and may exist adjacent to stationary surfaces in vessels in which the flow is predominantly turbulent.
10. The primary mechanism responsible for mixing at the molecular level is called _____
a) Bulk transport
b) Laminar mixing
c) Molecular diffusion
d) Lambda Mixing
Answer
Answer: c [Reason:] The primary mechanism responsible for mixing at the molecular level is diffusion resulting from the thermal motion of the molecules.
