Engineering Questions with Answers - Multiple Choice Questions

# Food Engineering MCQ’s – Unit Operations – Mixing-1

1 - Question

Which of the following with respect to mixing is true?
a) It is used to distribute heat uniformly to all the components of the mixture
b) Mixing becomes difficult when one of the phases to be mixed is in minor quantity
c) Solid-solid mixing is more difficult than other phases
d) All of the mentioned
Explanation: All of the mentioned sentences are true with respect to mixing.

2 - Question

Statement 1: Root mean square is denoted by σ2
Statement 2: σ2 will show the variation of a composition obtained after mixing. Hence the lesser it is, the more efficient is the mixing.
a) True, False
b) True, True
c) False, False
d) False, True
Explanation: Root mean square is denoted by σ2. σ2 will show the variation of a composition obtained after mixing. Hence the lesser it is, the more efficient is the mixing.

3 - Question

Mixing index is applicable for mixing of solids at zero time.
a) True
b) False
Explanation: Mixing index is applicable for mixing of solids at zero time.

4 - Question

Which of the following conditions show that a certain industrial mixer is the best?
a) Power load for mixing is minimum
b) Standard deviation is minimum
c) Time required for mixing is minimum
d) All of the mentioned
Explanation: All of the mentioned conditions show that a certain industrial mixer is the best.

5 - Question

Mixing Index is a ratio of the standard deviation of various products during mixing to that at zero mixing.
a) True
b) False
Explanation: Mixing Index is a ratio of the standard deviation of various products during mixing to that at zero mixing.

6 - Question

Rate of mixing at any time is given by the extent of mixing at that particular time.
a) True
b) False
Explanation: Rate of mixing at any time is given by the extent of mixing at that particular time.

7 - Question

The force used for mixing by mixing equipment for pastes and dough is _____
a) Centrifugal smearing
b) Impact
c) Tumbling
d) All of the mentioned
Explanation: The force used for mixing by mixing equipment for pastes and dough can be any of the mentioned.

8 - Question

The clearance between the impeller and the vessel in a mixer is usually kept _____
a) High
b) Low
c) Cannot be determined
d) None of the mentioned
Explanation: The clearance between the impeller and the vessel is usually kept low to avoid stagnant zones.

9 - Question

Statement 1: Kneaders are specially used for pastry/viscous liquids in the food industry.
Statement 2: Kneaders are used for mixing dough with fats and making them homogeneous mixtures.
a) True, False
b) True, True
c) False, False
d) False, True
Explanation: Kneaders are specially used for pastry/viscous liquids in the food industry. Kneaders are used for mixing dough with fats and making them homogeneous mixtures.

10 - Question

Statement 1: Effectiveness of mixing in kneaders depends on the blade design.
Statement 2: Kneaders have a high clearance between the two oppositely rotating blades and the vessel.
a) True, False
b) True, True
c) False, False
d) False, True
Explanation: Effectiveness of mixing in kneaders depends on the blade design. Kneaders have a high clearance between the two oppositely rotating blades and the vessel, unlike other mixers which have low clearance.

11 - Question

Statement 1: Which mixture is used when one of the components is very less in quantity?
Statement 2: This mixer is used to mix items in savory or a snack item.
a) Ribbon mixer, planetary mixer
b) Planetary mixer, double cone mixer
c) Double cone mixer, double cone mixer
d) Planetary mixer, planetary mixer
Explanation: Double cone mixer is used when one of the components is very less in quantity. This mixer is used to mix items in savory or a snack item.

12 - Question

Which of the following is true with respect to mixing operations in the food industry?
a) Ice creams
b) Confectionery products
c) Chlorinated waters
d) All of the mentioned