Home/Important MCQs/Mechanical Operations/MCQs

Mechanical Operations MCQs

Free 445+ Mechanical Operations MCQs for PPSC, FPSC, NTS, and Pakistan government job tests. Practise below with answers and explanations.

445 MCQs available← Back to Mechanical Operations

All Subjects

Categories are collapsed by default. Use search to jump.

Search categories

Agriculture MCQs
Accounting Mcqs
•ASF ACT 1975 Mcqs
Auditing Mcqs
•Computer Science
Economics Mcqs
English Literature Mcqs
•Everyday Science Mcqs
Finance Mcqs
Forestry Mcqs
HRM Mcqs
International Relations
Judiciary And Law Mcqs
Marketing Mcqs
Mechanical Engineering Mcqs
PAST PAPERS
•Pharmaceutical Chemistry Mcqs
•Philosophy
•Photography Mcqs
Sociology Mcqs
Zoology Mcqs
General Knowledge MCQs
•Biology Mcqs
Chemistry Mcqs
Physics Mcqs
Statistics Mcqs
English Mcqs
Computer Mcqs
Medical Mcqs
Pedagogy Mcqs

445 questions in this list. Select an option to practice, or open a question for the full page with explanation.

About this subject

Mechanical Operations

Show Answers

Correct options are highlighted when revealed.

1.Identify the incorrect statement from the following options:

Magnetic separation is applicable for processing both dry and wet ores.The reduction ratio in crushing is the ratio of the smallest feed size to the largest product size.Gyratory crushers are utilized for primary coarse crushing tasks.Screens can be classified as stationary, moving, or vibratory types.

2.Identify the incorrect statement from the following options:

Cumulative analysis is favored over differential analysis for calculating surface area.A gate diagram plots the cumulative percentage by weight undersize against the inverse of particle diameter.Choke feeding a crusher results in a decrease in its capacity.In tumbling mills, the movement of pebbles or balls rolling from the top to the bottom of the pile is known as 'cascading'.

3.Identify the incorrect statement from the following:

In a compressible cake, both the voidage and specific resistance can be considered constant.The resistance offered by the cake does not vary with changes in pressure drop.Dry grinding is used for crushing explosive substances.A gyratory crusher is classified as a coarse crusher.

4.Identify the incorrect statement about the turbine agitator from the options below:

The suggested peripheral speed for a turbine agitator ranges between 200 and 250 meters per minute.A pitched blade turbine agitator produces solely radial flow without any axial flow component.Typically, the agitator diameter is maintained between one-third to one-sixth of the tank diameter.The turbine agitator must be positioned at a minimum height equal to one agitator diameter above the tank bottom.If the liquid depth exceeds twice the agitator diameter, it is advisable to use two agitators.

5.Identify the accurate statement from the following options:

The angle of repose is consistently larger than the angle of sliding.A hopper is a small container featuring an inclined base.A silo is a short, wide vessel designed to store highly volatile materials.Pine oil serves as a 'modifying agent' to influence the adsorption of froth flotation agents.

6.Identify the accurate statement from the following options:

Plastic granules are classified as non-cohesive solids.Kick’s law for crushing is expressed as P/m = K × ln(D̅ sa / D̅ sb).Comminution refers to the process of increasing particle size.The energy in kWh per ton needed for 80% of material to pass a 200 mesh is known as the work index.

7.Identify the incorrect statement regarding roll crushers.

The size of the largest feed controls the diameter of the rolls needed.When crushing hard materials, the reduction ratio should be limited to 4 or less.The two rolls must always operate at identical speeds.The production output and energy usage per unit are influenced by the reduction ratio and the difference in roll speeds.

8.Identify the incorrect statement from the following options:

The term 'circulating load' refers to the coarse material returned to the grinder by a classifier.Wet crushing causes more wear and tear compared to dry crushing of materials.Increasing particle size (the reverse of size reduction) is considered a mechanical process.A 'dust catcher' is an expanded section in a pipeline that allows particles to settle out.

9.Identify the incorrect statement from the following:

Closed circuit grinding is more cost-effective compared to open circuit grinding.Grinding aids in the cement industry include substances like cod oil, beef tallow, or aluminum stearates.A classifier is a device designed to eliminate minute solid particles from a liquid.Mechanical size increase is demonstrated in processes such as the manufacturing of medicinal tablets.

10.Which of the following statements is accurate?

Iron must be extracted from ceramic materials using magnetic separation to prevent discoloration.The cost to operate a shaking screen exceeds that of a vibrating screen.The capacity of a screen is unaffected by the mineral's specific gravity.Toothed roll crushers are ideal for crushing asphalt.

11.Identify the incorrect statement from the following:

Hammer crushers function through impact forces.Typical screens feature circular-shaped openings.As the mesh number of a screen rises, the size of the openings in microns gets smaller.A 200 mesh screen contains 200 openings per centimeter in a straight line.

12.Which of the following statements is accurate?

The capacity and efficiency of a screen are identical.Capacity and efficiency of a screen work against each other.The screening surface of a 'reel' in flour mills is constructed from silk bolting cloth.Both statements B and C are true.

13.The principle of ore concentration through jigging relies on the variation in which characteristic of the particles?

Specific gravitySurface wetting propertiesParticle formNo differences apply

14.What effect do baffles have on the flow pattern in agitators?

They reduce swirling motionThey decrease vortex formationThey eliminate both swirling and vortexingThey have no impact on swirling or vortexing

15.The actual operating speed of a ball mill typically ranges between 65% and 80% of its critical speed. For which of the following processes is it necessary to run the ball mill at the highest percentage of the critical speed?

Wet milling in a low-viscosity slurryWet milling in a high-viscosity slurryDry milling of large particles up to 1.25 cm in sizeDry milling of large particles in mills without internal bafflesNone of the above