Mechanical Operations Mcqs for Chemical - Set 4

1)   Reciprocal of sphericity is termed as the________________?

a. Specific surface ratio
b. Shape factor
c. Sauter diameter
d. Surface area per unit mass
Answer  Explanation 

ANSWER: Shape factor

Explanation:
No explanation is available for this question!


2)   Filtration of water in a paper mill is done by a/an _______________ filter?

a. Open sand
b. Plate and frame
c. Vacuum leaf
d. Sparkler
Answer  Explanation 

ANSWER: Open sand

Explanation:
No explanation is available for this question!


3)   With increase in the capacity of screens, the screen effectiveness__________________?

a. Remains unchanged
b. Increases
c. Decreases
d. Decreases exponentially
Answer  Explanation 

ANSWER: Decreases

Explanation:
No explanation is available for this question!


4)   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) ?

a. LS
b. 93 LS
c. 250 LS
d. √(LS)
Answer  Explanation 

ANSWER: 93 LS

Explanation:
No explanation is available for this question!


5)   To get a fine talc powder from its granules, the equipment used is____________________?

a. Roller crusher
b. Ball mill
c. Jaw crusher
d. Gyratory crusher
Answer  Explanation 

ANSWER: Ball mill

Explanation:
No explanation is available for this question!


6)   The controlling resistance in a rotary drum vacuum filter is the ________________ resistance?

a. Piping
b. Cake
c. Filter medium
d. None of these
Answer  Explanation 

ANSWER: Cake

Explanation:
No explanation is available for this question!


7)   Separation of particles of various sizes, shapes and densities by allowing them to settle in a fluid is called__________________?

a. Classification
b. Froth floatation
c. Thickening
d. Clarification
Answer  Explanation 

ANSWER: Classification

Explanation:
No explanation is available for this question!


8)   Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls in rotation per second (rps) D = diameter of rolls, m) ?

a. 3.6 V.W.Dr.ρ
b. 3.6 V.W. ρ
c. 3.6 W.Dr.ρ
d. 3.6 V.W.Dr/ρ
Answer  Explanation 

ANSWER: 3.6 V.W.Dr.ρ

Explanation:
No explanation is available for this question!


9)   In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of _______________ crushing?

a. Primary
b. Secondary
c. Fine
d. Ultrafine
Answer  Explanation 

ANSWER: Fine

Explanation:
No explanation is available for this question!


10)   A fluid energy mill is used for __________________?

a. Cutting
b. Grinding
c. Ultra-grinding
d. Crushing
Answer  Explanation 

ANSWER: Ultra-grinding

Explanation:
No explanation is available for this question!


11)   Reciprocating screens are normally inclined at an angle of 5° with the horizontal and employ gyratory motion at feed end & reciprocating motion at the discharge end. They are not suitable for the screening of the ___________________?

a. Light metal powder down upto 4 mesh size
b. Dry chemicals
c. Heavy tonnages of rocks or gravel
d. Powdered food & granular materials
Answer  Explanation 

ANSWER: Heavy tonnages of rocks or gravel

Explanation:
No explanation is available for this question!


12)   Gravity stamp mill is meant for the ___________________ crushing?

a. Primary
b. Intermediate
c. Fine
d. Ultrafine
Answer  Explanation 

ANSWER: Fine

Explanation:
No explanation is available for this question!


13)   For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter) ?

a. π = (A/D2)
b. π/6 = (V/D3)
c. AD/V
d. None of these
Answer  Explanation 

ANSWER: π = (A/D2)

Explanation:
No explanation is available for this question!


14)   _______________ mixer is used for devulcanisation of rubber scrap & making water dispersion & rubber solution?

a. Tumbler
b. Banbury
c. Muller
d. Ribbon blender
Answer  Explanation 

ANSWER: Banbury

Explanation:
No explanation is available for this question!


15)   Which of the following is a fine crusher ?

a. Blake jaw crusher
b. Gyratory crusher
c. Toothed roll crusher
d. Dodge jaw crusher
Answer  Explanation 

ANSWER: Toothed roll crusher

Explanation:
No explanation is available for this question!


16)   Maximum size reduction in a ball mill is done by the, ______________ action?

a. Attrition
b. Compression
c. Impact
d. Cutting
Answer  Explanation 

ANSWER: Impact

Explanation:
No explanation is available for this question!


17)   The reduction ratio for grinders is defined as (where, Df and Dp are average diameters of feed and product respectively) ?

a. Df/Dp
b. Dp/Df
c. Df – Dp
d. None of these
Answer  Explanation 

ANSWER: Df/Dp

Explanation:
No explanation is available for this question!


18)   Sphericity of pulverised coal is__________________?

a. 1
b. < 1
c. > 1
d.
Answer  Explanation 

ANSWER: < 1

Explanation:
No explanation is available for this question!


19)   Gummy & sticky materials like molasses, sugar etc. are best transported/handled by using a ______________ conveyor?

a. Drag
b. Ribbon
c. Screw
d. Slat
Answer  Explanation 

ANSWER: Ribbon

Explanation:
No explanation is available for this question!


20)   There is practically no alternative/competitor to _________________ in the beneficiation treatment of sulphide ores?

a. Classification
b. Tabling
c. Jigging
d. Froth floatation
Answer  Explanation 

ANSWER: Froth floatation

Explanation:
No explanation is available for this question!


21)   With increase in the pressure drop across the cake, the specific cake resistance for the compressible sludge________________?

a. Increases
b. Decreases
c. Remains constant
d. Increases linearly
Answer  Explanation 

ANSWER: Increases

Explanation:
No explanation is available for this question!


22)   Which of the following clay mixing devices is vacuum operated for deairation of clay ?

a. Banbury mixer
b. Pug mill
c. Muller-mixer
d. None of these
Answer  Explanation 

ANSWER: Pug mill

Explanation:
No explanation is available for this question!


23)   Introduction of slurry in a plate and frame filter press is done through a plate in each frame. The plate of this filter has a _______________ surface?

a. Plane
b. Curved
c. Ribbed
d. Either A. or B.
Answer  Explanation 

ANSWER: Ribbed

Explanation:
No explanation is available for this question!


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

a. Different fluids
b. Same fluid
c. Same field of force
d. Both B. and C.
Answer  Explanation 

ANSWER: Both B. and C.

Explanation:
No explanation is available for this question!


25)   Which is the most suitable conveyor for transportation of sticky material ?

a. Apron conveyor
b. Belt conveyor
c. Screw conveyor
d. Pneumatic conveyor
Answer  Explanation 

ANSWER: Screw conveyor

Explanation:
No explanation is available for this question!


26)   Dry powdery solid materials are transported by a ______________ conveyor?

a. Belt
b. Bucket
c. Screw
d. None of these
Answer  Explanation 

ANSWER: Screw

Explanation:
No explanation is available for this question!


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

a. Toothed roll crusher
b. Gyratory crusher
c. Ball mill
d. Tube mill
Answer  Explanation 

ANSWER: Gyratory crusher

Explanation:
No explanation is available for this question!


28)   Fluid energy mill comes in the category of________________?

a. Grinder
b. Crusher
c. Cutter
d. Ultrafine grinder
Answer  Explanation 

ANSWER: Ultrafine grinder

Explanation:
No explanation is available for this question!


29)   Molten ammonium nitrate is mixed with ground limestone in fertilizer plant in a__________________?

a. Pug mill
b. Mixer-extruder
c. Banbury mixer
d. Muller mixer
Answer  Explanation 

ANSWER: Pug mill

Explanation:
No explanation is available for this question!


30)   Wheat is ground into flour in a___________________?

a. Hammer crusher
b. Roller crusher
c. Impact mill
d. Fluid energy mill
Answer  Explanation 

ANSWER: Roller crusher

Explanation:
No explanation is available for this question!