Mechanical Operations MCQs

Question 1

As particle size is reduced

Accepted Answer

Screening becomes progressively more difficult

Answer

Screening becomes progressively easier

Answer

Capacity and effectiveness of the screen is increased

Answer

None of these

Question 2

Which of the following oxides is not present in hematite iron ore?

Accepted Answer

Cobalt oxide

Answer

Titanium oxide

Answer

Calcium oxide

Answer

Manganese oxide

Question 3

Pick out the wrong statement.

Accepted Answer

Size enlargement (opposite of size reduction) is not a mechanical operation

Answer

Recycled coarse material to the grinder by a classifier is termed as circulating load

Answer

Wear and tear in wet crushing is more than that in dry crushing of materials

Answer

A 'dust catcher' is simply an enlargement in a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas

Question 4

Tabular bowl centrifuges as compared to disk bowl centrifuges

Accepted Answer

Operate at higher speed

Answer

Employ bowl of larger diameter

Answer

Can't be operated under pressure/vacuum

Answer

Can't be used for separation of fine suspended solids from a liquid

Question 5

increasing the capacity of a screen __________ the screen effectiveness.

Accepted Answer

Decreases

Answer

Increases

Answer

Does not effect

Answer

None of these

Question 6

__________ is the most commonly used 'filter aid'.

Accepted Answer

Diatomaceous earth

Answer

Fuller's earth

Answer

Vermiculite

Answer

Semi-plastic clay

Question 7

Dispersion of a gas through liquid is done by using a

Accepted Answer

Sparger

Answer

Kneader

Answer

Masticator

Answer

None of these

Question 8

For a sphere falling in the constant drag co-efficient regime, its terminal velocity depends on its diameter (d) as

Accepted Answer

d 2

Answer

d

Answer

$$\sqrt {	ext{d}} $$

Answer

$$\frac{1}{{	ext{d}}}$$

Question 9

Capacity of flight conveyor in tons/hr is given by (where, W & D = width and depth of flight respectively in metre, V = speed of the conveyor, metre/second, ρ = bulk density of material, kg/m 3 )

Accepted Answer

3.6 W.D.V.ρ

Answer

3.6 W.D.V.

Answer

3.6 W.V.ρ

Answer

3.6 D.V.ρ