1. Which fluids are having a constant viscosity dependent on temperature but independent of the applied shear rate?
a) Non-Newtonian
b) Newtonian
c) Dry
d) Wet
Discussion
Explanation: Newtonian fluids are those having a constant viscosity dependent on temperature but independent of the applied shear rate. Dry and wet are irrelevant
2. A Newtonian fluid is defined as the fluid which?
a) Obeys hook’s law
b) Is compressible
c) Obey Newton’s law of viscosity
d) Is incompressible
Discussion
Explanation: Newtonian fluid is defined as the fluid which obeys Newton’s law of viscosity for a Newtonian fluid. The viscosity curve, which is a plot of viscosity versus shear rate, will show a straight line at a constant value equal to h.
3. Property of fluid that describes its internal resistance is known as __________
a) Viscosity
b) Friction
c) Resistance
d) Internal energy
Discussion
Explanation: Property of fluid that describes its internal resistance is called viscosity. Friction is the force resisting the relative motion of fluid layers.
4. Stress strain relationship for a Newtonian fluid is __________
a) Hyperbolic
b) Parabolic
c) Linear
d) Inverse type
Discussion
Explanation: Newtonian fluid has a linear stress strain relationship. The increase in stress directly corresponds to increase in strain.
5. For non-Newtonian fluids, apparent viscosity is a function of __________
a) shear rate
b) flow rate
c) viscous rate
d) specific rate
Discussion
Explanation: Non Newtonian fluid apart from being shear rate dependent.T he viscosity of non-Newtonian fluids may also be time dependent.
6. Which of the following are now Newtonian material which is time independent?
a) Thixotropic
b) Rheo-pectic
c) Anti-thixotropic
d) Plastic
Discussion
Explanation: Non-Newtonian materials that are time independent are defined as shear thinning. They can also be shear thickening or plastic.
7. Which of the following are now Newtonian materials which are time dependent?
a) Shear thickening
b) Rheo-pectic
c) Shear thinning
d) plastic
Discussion
Explanation: Non-Newtonian materials that are time dependent are defined as thixotropic. They can also be rheopectic or anti-thixotropic.
8. Which among the following is not the example of thixotropic fluid?
a) Yogurt
b) Ice cream
c) Mayonnaise
d) Milk
Discussion
Explanation: Typical examples of thixotropic fluids are yoghurt. Mayonnaise, margarine, ice cream and brush paint also come in the same category.
9. At 30℃, water has the viscosity of __________
a) 0.801
b) 1
c) 2
d) 6.29
Discussion
Explanation: Water has the viscosity of 0.801 at the temperature of 30℃. Water at 20.2oC (68.4oF) has the absolute viscosity of one – 1 – centipoises.
10. Viscosity of milk and milk products is important in not determining __________
a) the rate of creaming
b) rates of mass and heat transfer
c) the flow conditions in dairy processes
d) spoilage rate
Discussion
Explanation: Viscosity of milk and milk products plays an important role in determining the rate of creaming. It also helps in determining rates of mass and heat transfer and flow conditions in the dairy process.