Engineering Questions with Answers - Multiple Choice Questions

Mechanical Operations MCQ’s– Equipments Operations

1 - Question

Collectors forms ____
a) Films
b) Forth
c) Bubbles
d) Scale

View Answer

Answer: a
Explanation: Collectors are the material which form surface films on the particles, these films are thicker that produced by promoters.

2 - Question

Which of the following is a collector?
a) Sodium ethyl Xanthate
b) Pine oil
c) Timber oil
d) Cocoa oil

View Answer

Answer: b
Explanation: Pine oil is a most commonly used collector, petroleum compounds are generally used though they are greasy forth maker.

3 - Question

Surfaces in either cases are manipulated using ____
a) Changer
b) Modifiers
c) Striker
d) Maroekater

View Answer

Answer: b
Explanation: Surface manipulation can be done using the substances called as modifiers which either absorbed on the surface of particle or react chemically.

4 - Question

Which of the following is the right order?
a) Forth > Modifier > Collector
b) Forth < Modifier < Collector
c) Forth > Collector > Modifier
d) Forth < Collector < Modifier

View Answer

Answer: d
Explanation: Initially forth is formed using a suitable forthing agent and then collectors can be applied to increase the film thickness and if needed modifiers are used.

5 - Question

Which of the following can mostly affect the flotation process?
a) Pressure
b) Temperature
c) pH
d) Rate of reaction

View Answer

Answer: c
Explanation: The pH which is a regulating or critical factor can affect the flotation process and can be adjusted by lime, caustic soda and soda ash.

6 - Question

What does the below equation represent?

Cf=[1-dp/Dc ]2.25
a) Francis factor
b) Newton factor
c) Belly factor
d) Nauman factor

View Answer

Answer: a
Explanation: For laminar settling of a spherical particle in a cylindrical vessel, Francis has proposed a correction factor, Where De is diameter of container.

7 - Question

 When carried correct calculation the following equation results in ___
ρs (1-ε)+ρf ε
a) Final density
b) Bulk density
c) Bulk Volume
d) Final Volume

View Answer

Answer: b
Explanation: The bulk density ρ_b can be calculated by the above equation, where ε is the volume of fraction void liquid in a suspension.

8 - Question

When the particle have the same terminal velocity, they are said to be ___
a) Kinematical falling
b) Partially falling
c) Equally falling
d) Free falling

View Answer

Answer: b
Explanation: The basic criterion of separation of particles A and B are the difference in the terminal velocity, but when it is equal they are said to be equally falling.

9 - Question

 The ratio of sizes of equally falling particles is called ___
a) Reflux ratio
b) Reduction ratio
c) Settling ratio
d) Steeling ratio

View Answer

Answer: c
Explanation: The ratio of sizes of particles say A and B when they are equally falling is called as the settling ratio i.e. DA/DB.

10 - Question

What is the laboratory test defined for heavy medium separation?
a) Float and sink test
b) Weight test
c) Bubble test
d) Forth test

View Answer

Answer: a
Explanation: In commercial practices, a sample feed is first tested in the laboratory using what is called the float and sink test experiment.

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