A liquid that follows Newtonian flow has:
a. Variable viscosity
b. Constant viscosity regardless of shear
c. Yield value
d. Shear-thickening behavior
B. Constant viscosity regardless of shear
Which of the following is pseudoplastic?
a. Butter
b. Ointment
c. Tragacanth
d. Starch suspension
c. Tragacanth
A Bingham body exhibits:
a. No yield value
b. Constant viscosity
c. Yield stress before flow
d. Shear-thinning
c. Yield stress before flow
Dilatant materials show:
a. Viscosity decreases with shear
b. Viscosity increases with shear
c. Constant viscosity
d. Plastic flow
b. Viscosity increases with shear
Ostwald viscometer determines viscosity based on:
a. Rotational resistance
b. Flow time through a capillary
c. Light refraction
d. Drop weight
b. Flow time through a capillary
Viscosity is also known as:
a. Internal friction
b. External surface tension
c. Molecular density
d. Fluid cohesion
a. Internal friction
Unit of viscosity:
a. dynes/cm
b. g/cm·sec
c. poise
d. both b and c
d. both b and c
Shear stress is symbolized as:
a. α
b. η
c. τ
d. γ
c. τ
Newtonian flow shows what relationship?
a. Inverse
b. No relationship
c. Direct proportionality
d. None
c. Direct proportionality
A material that requires yield value before flowing is:
a. Dilatant
b. Pseudoplastic
c. Plastic
d. Newtonian
c. Plastic
Plastic flow is characteristic of:
a. True solutions
b. Flocculated suspensions
c. Alcoholic gels
d. Volatile oils
b. Flocculated suspensions
A pseudoplastic liquid shows:
a. Shear-thickening
b. Shear-thinning
c. No change in viscosity
d. Abrupt solidification
b. Shear-thinning
Dilatant systems are also called:
a. Shear-thin
b. Shear-thick
c. Newtonian
d. Elastic
b. Shear-thick
Which is Newtonian?
a. Margarine
b. Starch suspension
c. Water
d. Paste
c. Water
Cup and bob viscometer works on:
a. Falling ball method
b. Resistance to rotation
c. Light absorption
d. Density measurement
b. Resistance to rotation
Cone and plate viscometer uses a:
a. Capillary
b. Rotating cone
c. Pressure tube
d. Thermal plate
b. Rotating cone
Ostwald viscometer measures:
a. Absolute viscosity only
b. Relative viscosity only
c. Flow time of liquid
d. Density
c. Flow time of liquid
Surface tension is caused by:
a. Gravity
b. Cohesion between liquid molecules
c. Evaporation
d. Adhesion only
b. Cohesion between liquid molecules
Surfactants work mainly by:
a. Increasing density
b. Decreasing surface tension
c. Increasing viscosity
d. Preventing dissolution
b. Decreasing surface tension
Anionic surfactants have:
a. Positive charge
b. No charge
c. Negative charge
d. Zwitterionic charge
c. Negative charge
Example of a cationic surfactant:
a. Tween
b. SDS
c. Benzalkonium chloride
d. LAS
c. Benzalkonium chloride
The drop weight method uses:
a. Refractometer
b. Polarimeter
c. Stalagmometer
d. Colorimeter
c. Stalagmometer
Capillary rise depends on:
a. Mass of drops
b. Density, height, and radius
c. Light wavelength
d. Liquid evaporation
b. Density, height, and radius
Surface tension tends to:
a. Increase surface area
b. Minimize surface area
c. Create irregular droplets
d. Lower cohesion
b. Minimize surface area
