1. Skim milk exhibit which of the following flow behavior?
a) Newtonian
b) Non Newtonian
c) Pseudo plastic
d) Diliant
Discussion
Explanation: Skim milk has Newtonian behavior. It shows stress and strain directly corresponding to each other.
2. Viscosity of Skim milk depends on __________
a) Temperature
b) pH
c) Temperature and pH
d) Moisture
Discussion
Explanation: Viscosity of Skim milk is dependent on temperature. The pH of milk also plays a vital role in determining the viscosity of skim milk.
3. Decrease in temperature of milk leads to _______ in viscosity.
a) Parabolic decrease
b) Linear decrease
c) Constant
d) Increase
Discussion
Explanation: Cooler temperatures increase viscosity. This can be due to the voluminosity of casein micelles.
4. Temperatures above 65° C _______ viscosity of skim milk.
a) Parabolic decrease
b) Linear decrease
c) Constant
d) Increase
Discussion
Explanation: In skim milk, temperatures above 65° C increase viscosity. This is due to the denaturation of whey proteins.
5. Cooled raw milk and cream exhibit which of the following flow behavior?
a) Newtonian
b) Non Newtonian
c) Sticky
d) None
Discussion
Explanation: Cooled raw milk and cream show non-Newtonian behavior in which the viscosity is dependent on the shear rate
6. Which of the following factors does not affect the viscosity of milk?
a) State and concentration of proteins
b) State and concentration of Fat
c) Temperature and Age of Milk
d) Spoilage
Discussion
Explanation: Important factors that influence the viscosity of milk are State and concentration of protein. State and concentration of fat; Temperature of milk and Age of the milk also influence viscosity.
7. The unit of viscosity is __________
a) Gamma
b) Pascal
c) Poise
d) Bar
Discussion
Explanation: The unit of viscosity is poise. Bar is the unit of pressure. Pascal is also a unit of pressure
8. Lactose, whey proteins and milk salts have less contribution towards the viscosity of milk compared with the casein which alone is contributing substantially towards this property.
a) True
b) False
Discussion
Explanation: The statement is true. Lactose, whey proteins and milk salts contribute less towards the viscosity. Casein contributes substantially towards this property.
9. The force required to maintain a relative velocity of 1cm/sec between two parallel planes placed 1 cm apart is called ________
a) acceleration
b) buoyancy force
c) viscosity
d) flow
Discussion
Explanation: The force required to maintain a relative velocity of 1cm/sec between two parallel planes placed 1 cm apart is called viscosity. It has a unit of poise.
10. Flow is a kind of __________
a) Breakage
b) Reversible deformation
c) Irreversible deformation
d) Liquid
Discussion
Explanation: Flow is an irreversible deformation. Irreversible deformation can be defined as a state when a matter is not reverted to the original state when the force is removed