Engineering Questions with Answers - Multiple Choice Questions

Mechanical Operations MCQ’s – Mixing Equipments

1 - Question

Ore concentration by jigging is based on the difference in the _______ of the particles.
a) Specific gravities
b) Wet ability
c) Shape
d) Size

View Answer

Answer: a
Explanation: Jigging is a method of gravitational preparation of natural resources, based on separation of mineral mixture on density in vertically oscillating water stream.

2 - Question

Traces of liquid tar fog present in coke oven gas is separated using _________
a) Electrostatic precipitator
b) Cyclone separator
c) Strainer
d) Vibrating screen

View Answer

Answer: a
Explanation: The traces cannot be separated by a normal means that is why, it is charged with a static charger and then separated in an electrostatic separator.

3 - Question

In case of revolving mill, wet grinding compared to dry grinding ___________
a) Requires more energy
b) Has less capacity
c) Complicates handling and classification of the product
d) Effects the motion of the ball

View Answer

Answer: d
Explanation: Wet grinding sustainably require less motion of the ball as they are already mixed with a medium.

4 - Question

Froth floatation is the most suitable for treating _________
a) Iron ores
b) Supplied ores
c) Quartile
d) Iron ores

View Answer

Answer: b
Explanation: Supplied ores can easily be separated using difference in the settling velocity, and thus can be easily separated.

5 - Question

 For beneficiation of iron ore, the most commonly used method is ________
a) Flocculation
b) Froth floatation
c) Jigging and tabling
d) Filter

View Answer

Answer: c
Explanation: Jigging involves the separation due to specific gravity and tabling involves concentration of pulp material thus best for iron ore sepration.

6 - Question

Screen capacity is expressed in terms of ________
a) Tons/hr
b) Tons/ft2
c) Tons
d) Tons/hr-ft2

View Answer

Answer: d
Explanation: The capacity of screen is represented by amount of material per unit time and required are, i.e. Tons/hr-ft2.

7 - Question

The energy consumed by ball mill depends on _________
a) Its speed
b) Density
c) Wettability
d) Electrical and magnetic properties

View Answer

Answer: d
Explanation: Energy depends on the consumption of electrical energy and if magnetic field is involved then magnetic properties also varies with energy.

8 - Question

Ultrafine grinders operate principally by _________
a) Slow compression
b) Impact
c) Attrition
d) Cutting action

View Answer

Answer: c
Explanation: Ultrafine grinders are involved for ultrafine particles which are below the range of 10 micrometer and involves attrition as phenomenon.

9 - Question

Size measurement of ultrafine particles can be best expressed in terms of _______
a) Cm
b) Screen size
c) Micron
d) Surface area per unit mass

View Answer

Answer: d
Explanation: The measurement of ultrafine particles are usually expressed as in surface area per unit mass and secondarily in microns.

10 - Question

A screen is said to be blinded when the _________
a) Oversized is present in the undersize fraction
b) Undersized is present in the oversize fraction
c) Screen is plugged with solid particles
d) Screen capacity is abruptly increased

View Answer

Answer: a
Explanation: When the oversized is present in the undersize the screen is said to be inefficient, and can cause defect in separation.

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