1. From 300 and 10,000, the pattern is in range of _______
a) Transition
b) Laminar
c) Transient
d) Eddy
Explanation: In general, below a Reynold’s number of 300, all impellors give viscous flow mixing between 300 and 10,000 the action is turbulent.
2. _______ is a method of mixing used with deformable plastic.
a) Stumping
b) Threading
c) Kneading
d) Carving
Explanation: Kneading is a method of mixing used with deformable plastic, it involves squashing folding it over on itself and squashing again.
3. A masticator is also called as _______
a) Intensive mixer
b) Preventive mixer
c) Gauge mixer
d) Prang mixer
Explanation: A two arm kneader handles suspensions, pastes and light plastic masses, these are often called as intensive mixers.
4. The desired ratio for kneaders is ________
a) 1.5:1
b) 2:1
c) 3:1
d) 4:1
Explanation: The circles of rotation of blades are usually tangential, so that the blades overlap in a desired ratio of 1.5:1.
5. To achieve successful mixing, the velocities imparted to the liquid are maximized by _______
a) Shafts
b) Impellors
c) Baffles
d) Turbines
Explanation:To achieve successful mixing, the radial and longitudinal velocities imparted to the liquid are maximised by baffles, off-centre or angled mixer shafts, or angled blades.
6. _____ mixing is achieved by creating and recombining fresh surfaces.
a) Efficient
b) Worst
c) Economic
d) Normal
Explanation: Efficient mixing is achieved by creating and recombining fresh surfaces in the mixture as often as possible, it is necessary either to move the mixer blades throughout the vessel.
7. ______ are used to avoid buildup of sticky material.
a) Overlapping blades
b) Sigma blades
c) Impellor
d) Propeller
Explanation: Overlapping blades are used to avoid the buildup of sticky material on the blades while with tangential blades it is not so.
8. Which of the following is best for kneading?
a) Sigma
b) Propeller
c) Impellor
d) Agitator
Explanation: The common sigma blade is used for general purpose of kneading, it is capable of starting and operating with other solids and liquids.
9. _____ is used for rough and rubber type materials.
a) Exhausting
b) Multiwipping
c) Seeking
d) Multiscraping
Explanation: Multiwipping overlapping blades are used for the mixture which are tough and rubber like, the blade cuts the material into pieces.
10. What is the range impellor diameter?
a) 30 to 60% of diameter
b) 50 to 80% of diameter
c) 100% of diameter
d) 10 to 30% of diameter
Explanation:The impellor diameter is usually between 30 to 60% of the tank diameter, usually with two or four blades they may be high.