|
1) Filter medium resistance is that offered by the__________________? a. Filter cloth b. Embedded particles in the septum c. Filter cloth and the embedded particle collectively d. None of these
|
||||
|
2) Pick out the wrong statement ? a. Gape is the greatest distance between the crushing surfaces or the jaws b. The angle of nip (2α) is the angle between roll faces at the level where they will just take hold of a particle and draw it in the crushing zone c. Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing d. Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product
|
||||
|
3) Energy consumption in a crusher decreases with increase in the________________________? a. Size of the product (at constant feed size) b. Capacity of the crushing machine c. Size of feed (at constant reduction ratio) d. All A., B. & C.
|
||||
|
4) Mixing of light fine powder such as insecticides is done by____________________? a. Banbury mixer b. Pug mill c. Impact wheels d. Kneader
|
||||
|
5) The equivalent diameter of channel of a constant non-circular cross-section of 3 cm by 6 cm will be _______________ cms? a. 20 b. 12 c. 8 d. 2
|
||||
|
6) A widely used size reduction equipment for ______________ is Bradford breaker? a. Talc b. Coal c. Iron core d. Wheat
|
||||
|
7) Fluid medium used in the classification technique of mineral beneficiation is_________________? a. Air b. Water c. Either A. or B. d. Neither A. nor B.
|
||||
|
8) Which of the following is not a non-metalliferous mineral ? a. Calcite b. Fluorspar c. Quartz d. Cassiterite
|
||||
|
9) Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill.) ? a. D b. 1/D c. D2.5 d. 1/D2.5
|
||||
|
10) Helical screw agitator is used for________________? a. Mixing highly viscous pastes b. Blending immiscible liquids c. Mixing liquids at very high temperature (> 250 °C) d. None of these
|
||||
|
11) Balls for ball mills are never made of_________________? a. Forged/cast steel b. Lead c. Cast iron d. Alloy steel
|
||||
|
12) In froth floatation, chemical agent added to cause air adherence is called___________________? a. Collector b. Frother c. Modifier d. Activator
|
||||
|
13) In a roll crusher, both the rolls_________________? a. Have the same diameter b. Are rotated towards each other c. Run either at the same or different speeds d. All A., B. and C.
|
||||
|
14) In a mixer, the quantity, (v. L/D) is termed as __________ number (where, v = longitudinal velocity of material, L = length of the mixer, D = diffusivity in axial mixing) ? a. Weber b. Peclet c. Brinkman d. Schmidt
|
||||
|
15) A pebble mill_________________? a. Is a ball mill b. Employs flints or ceramic pebbles as the grinding medium c. Is a tube mill lined with ceramic or other non-metallic liner d. Both B. and C.
|
||||
|
16) Mass flow of granular solid (M) through a circular opening of dia, D follows_____________________? a. M ∝ √D b. M ∝ D2 c. M ∝ D3 d. M ∝ D
|
||||
|
17) Size reduction does not occur due to compression in case of________________? a. Rod mills b. Gyratory crushers c. Jaw crushers d. Smooth roll crushers
|
||||
|
18) The capacity of a belt conveyor depends upon two factors. If one is the cross-section of the load, the other is the _____________ of the belt? a. Speed b. Thickness c. Length d. None of these
|
||||
|
19) The grinding in a hammer crusher takes place due to the_______________? a. Attrition b. Impact c. Both A. & B. d. Neither A. nor B.
|
||||
|
20) Which of the following is not an ultrafine grinder (colloid mill) ? a. Micronizers b. Agitated mills and fluid energy mills c. Toothed roll crusher d. Hammer mills with internal classification
|
||||
|
21) Compressibility co-efficient for an absolutely compressible cake is_______________? a. 0 b. 1 c. 0 to 1 d. ∞
|
||||
|
22) If dp is the equivalent diameter of a non-spherical particle, Vp its volume and sp its surface area, then its sphericity is φs is defined by________________? a. φs = 6 Vp/dpsp b. φs = Vp/dpsp c. φs = 6 dpSp/Vp d. φs = dpSp/Vp
|
||||
|
23) A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is_________________? a. 0.90 μm/s b. 1 μm/s c. 22.1 μm/s d. 0.02 μm/s
|
||||
|
24) Which of the following crushers can be considered as a combination of a jaw crusher and a roller crusher ? a. Rod mill b. Fluid energy mill c. Gyratory crusher d. Ball mill
|
||||
|
25) Handling of ashes and similar materials can be done best by a ______________ conveyor? a. Flight b. Drag or slat c. Belt d. Ribbon
|
||||
|
26) Size reduction of the ______________ can be suitably done by ball mills, crushing rolls and rod mills? a. Metalliferous ores b. Non-metallic ores c. Basic slags d. Asbestos & mica
|
||||
|
27) For spheres, the specific surface shape factor is given by___________________? a. AD/V b. D/V c. A/V d. √(AD/V)
|
||||
|
28) A _____________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end? a. Compartment b. Tube c. Rod d. Pebble
|
||||
|
29) Cake resistance is___________________? a. Important in the beginning of filtration b. Decreased with the time of filtration c. Independent of pressure drop d. None of these
|
||||
|
30) Colloid mills achieve size reduction mainly by___________________? a. Impact b. Attrition c. Cutting d. Compression
|
||||
