MECHANICAL OPERATIONS QUIZ

A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is

0.5

0.58

0.62

0.68

TRUE ANSWER : ?
YOUR ANSWER : ?

Use of baffles in agitators help in minimising the __________ tendency.

Neither A nor B

Both A & B

Swirling

Vortexing

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is a coarse crusher?

Tube mill

Gyratory crusher

Toothed roll crusher

Smooth roll crusher

TRUE ANSWER : ?
YOUR ANSWER : ?

The capacity of a gyratory crusher is __________ that of a jaw crusher with the same gape, handling the same feed & for the same product size range.

5 times

Same as

10 times

2.5 times

TRUE ANSWER : ?
YOUR ANSWER : ?

Driving force in case of filtration by a centrifuge is the

Centrifugal pressure exerted by the liquid

Formation of highly porous cake

Narrow diameter of the vessel

Speed of the centrifuge

TRUE ANSWER : ?
YOUR ANSWER : ?

Screen capacity is not a function of

Its openings size

Screening surface

Screening mechanism

Atmospheric humidity

TRUE ANSWER : ?
YOUR ANSWER : ?

The opening of a 200 mesh screen (Taylor series) is

74 mili-microns

0.0047 cm

0.0074 cm

0.0074 mm

TRUE ANSWER : ?
YOUR ANSWER : ?

As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms )

√LS

LS

250 LS

93 LS

TRUE ANSWER : ?
YOUR ANSWER : ?

Solid particles separation based on the difference in their flow velocities through fluids is termed as the

Classification

Elutriation

Clarification

Sedimentation

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is used for primary crushing of very hard lumpy materials?

Ball mill

Tube mill

Toothed roll crusher

Gyratory crusher

TRUE ANSWER : ?
YOUR ANSWER : ?

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