Mechanical Operations MCQs

Question 1

Choke crushing (in case of a Jaw crusher) compared to free crushing

Accepted Answer

Consumes more power

Answer

Results in increased capacity

Answer

Consumes less power

Answer

Both A and C

Question 2

The sphericity of a solid particle of cubical shape is

Accepted Answer

$${\left( {\frac{\pi }{6}} \right)^{\frac{1}{3}}}$$

Answer

$$\pi $$

Answer

$${\left( {\frac{\pi }{6}} \right)^{\frac{1}{2}}}$$

Answer

$$\frac{\pi }{3}$$

Question 3

Ultracentrifuges running at speeds upto 100000 rpm is normally used for the

Accepted Answer

Separation of isotopes based on their density or molecular weights difference

Answer

Concentration of rubber latex

Answer

Separation of cream from milk

Answer

Dewaxing of lubricating oil

Question 4

In classification, particles are said to be equal settling, if they have the same terminal velocities in the

Accepted Answer

Both B and C

Answer

Different fluids

Answer

Same fluid

Answer

Same field of force

Question 5

Mixing of plastic solids is generally facilitated by

Accepted Answer

Kneading

Answer

Dispersion

Answer

Mastication

Answer

None of these

Question 6

Energy consumption in a crusher decreases with increase in the

Accepted Answer

All of the above

Answer

Size of the product (at constant feed size)

Answer

Capacity of the crushing machine

Answer

Size of feed (at constant reduction ratio)

Question 7

__________ mill is not a revolving mill.

Accepted Answer

Cage

Answer

Pebble

Answer

Compartment

Answer

Tube

Question 8

Vibrating screens have capacity in the range of __________ tons/ft 2 .mm mesh size.

Accepted Answer

0.2 to 0.8

Answer

5 to 25

Answer

50 to 100

Answer

100 to 250

Question 9

During agitation of liquids, power consumption during laminar flow is not proportional to the

Accepted Answer

Density of the liquid

Answer

Viscosity of the liquid

Answer

Cube of impeller diameters

Answer

Square of rotational speed