Mechanical Operations MCQs

Question 1

General mechanism of size reduction in intermediate and fine grinder is by

Accepted Answer

Impact and attrition

Answer

Cutting action

Answer

Compression

Answer

Compression and tearing

Question 2

The value of 'angle of nip' is generally about

Accepted Answer

32°

Answer

16°

Answer

52°

Answer

64°

Question 3

Out of the following size reduction equipments, the maximum feed size can be accepted by the

Accepted Answer

Jaw crusher

Answer

Tube mill

Answer

Ball mill

Answer

Jet pulveriser

Question 4

What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls?

Accepted Answer

0.66

Answer

0.5

Answer

1

Answer

2.76

Question 5

Rittinger number which designates the new surface prduced per unit of mechanical energy absorbed by the material being crushed, depends on the

Accepted Answer

All of the above

Answer

State or manner of application of the crushing force

Answer

Ultimate strength of the material

Answer

Elastic constant of the material

Question 6

Cartridge filters are termed as 'edge' filters, because of the fact that the

Accepted Answer

Bulk of the solids are removed at the periphery of the disks

Answer

Disks have very sharp edge

Answer

Solids are not deposited at the edge of the disk

Answer

None of these

Question 7

Pick out the wrong statement.

Accepted Answer

Cutting machines mainly employ 'attrition' for size reduction of solids

Answer

More commonly used jaw crusher between Dodge jaw crusher and Blake jaw crusher is the later one

Answer

There are only four methods namely compression, impact, attrition and cutting, which the size reduction equipments employ

Answer

Operating principles of Dodge and Blake jaw crushers are combined in the working of universal jaw crushers

Question 8

Which of the following screens has the maximum capacity?

Accepted Answer

Vibrating screen

Answer

Grizzlies

Answer

Trommels

Answer

Shaking screen

Question 9

A tube mill compared to a ball mill

Accepted Answer

Has a higher length/diameter ratio

Answer

Produces a coarser product

Answer

Has a higher diameter/length ratio

Answer

Uses much larger balls