MCQOPTIONS
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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 6101. |
Hot, lumpy & abrasive materials are best transported by using a/an __________ conveyor. |
| A. | apron |
| B. | belt |
| C. | screw |
| D. | flight |
| Answer» B. belt | |
| 6102. |
Additives used for promoting the floccula-tion of particles is a/an |
| A. | electrolyte |
| B. | surface active agent |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 6103. |
In case of grinding in a ball mill |
| A. | wet grinding achieves a finer product size than dry grinding. |
| B. | its capacity decreases with increasing fineness of the products. |
| C. | grinding cost and power requirement increases with increasing fineness of the products. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 6104. |
The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area, m2 V = rising velocity of fluid, m/sec.S = percentage of solids in the suspension by volume. = density of solids, kg/m3) |
| A. | 3.6 AVS. |
| B. | 3.6 A.V. |
| C. | 3.6 A.S. |
| D. | 3.6 AVS/ |
| Answer» B. 3.6 A.V. | |
| 6105. |
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) |
| Answer» D. neither (a) nor (b) | |
| 6106. |
The maximum slope of a belt conveyor can be |
| A. | 15 |
| B. | 30 |
| C. | 45 |
| D. | 60 |
| Answer» C. 45 | |
| 6107. |
Sauter mean diameter is the same as the __________ mean diameter. |
| A. | mass |
| B. | arithmetic |
| C. | volume-surface |
| D. | geometric |
| Answer» D. geometric | |
| 6108. |
Sizing of very fine particles of the order of 5 to 10 microns is done by elutriation, which is a __________ operation. |
| A. | clarification |
| B. | sedimentation |
| C. | flocculation |
| D. | classification |
| Answer» E. | |
| 6109. |
In the cyclone separator used for separation of dust from dust laden gas, the gas |
| A. | enters the cyclone from the top. |
| B. | is admitted tangentially at high velocity. |
| C. | develops a helical motion inside the chamber. |
| D. | both (b) and (c). |
| Answer» E. | |
| 6110. |
The basic filtration equation is given as where, V is volume of the filtrate ; A is the filtration area, a is specific cake resistance, is viscosity of the filtrate, and C is the concentration of the solids in the feed slurry. In a 20 minutes constant rate filtration, 5 m3 of filtrate was obtained. If this is followed by a constant pressure filtration, how much more time in minutes, it will take for another 5 m3 of filtrate to be produced ? Neglect filter medium resistance, Rm ; assume incompressible cake. |
| A. | 10 |
| B. | 20 |
| C. | 25 |
| D. | 30 |
| Answer» C. 25 | |
| 6111. |
Size reduction of fibrous materials like wood, asbestos, mica etc. is done by a disintegrator exemplified by the |
| A. | Blake jaw crusher |
| B. | cage mill |
| C. | stamp mill |
| D. | Bradford's breaker |
| Answer» C. stamp mill | |
| 6112. |
The material is crushed in a gyratory crusher by the action of |
| A. | impact |
| B. | compression |
| C. | attrition |
| D. | cutting |
| Answer» C. attrition | |
| 6113. |
__________ are mixed using ribbon blenders. |
| A. | Lumpy solids and low viscosity liquids |
| B. | Dry powders |
| C. | High viscosity liquids |
| D. | Thick pastes |
| Answer» C. High viscosity liquids | |
| 6114. |
During agitation of liquids, the |
| A. | Froude number is independent for the curves between power number and Reynolds number in baffled system. |
| B. | Power number becomes independent of impellers Reynolds number at high Reynolds number, but is dependent on the geometry of the impeller. |
| C. | Froude number is used to account for the effect of surface (e.g., the centre vortex) on the power number. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 6115. |
For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to |
| A. | the new surface created. |
| B. | the size reduction ratio. |
| C. | the change in volume due to crushing. |
| D. | none of these. |
| Answer» B. the size reduction ratio. | |
| 6116. |
Gelatinous solid (which plug the septum) can be filtered by a __________ filter. |
| A. | sparkler |
| B. | plate and frame |
| C. | vacuum leaf |
| D. | precoat |
| Answer» E. | |
| 6117. |
During the washing of cake |
| A. | all the resistances are constant. |
| B. | filter medium resistance increases. |
| C. | filter medium resistance decreases. |
| D. | cake resistance decreases. |
| Answer» B. filter medium resistance increases. | |
| 6118. |
The opening of a 200 mesh screen (Taylor series) is |
| A. | 0.0074 cm |
| B. | 0.0074 mm |
| C. | 0.0047 cm |
| D. | 74 mili-microns |
| Answer» B. 0.0074 mm | |
| 6119. |
A gravity decanter is meant for the separation of two __________ density. |
| A. | immiscible liquids of different |
| B. | miscible liquids of different |
| C. | immiscible liquids of same |
| D. | miscible liquids of same |
| Answer» B. miscible liquids of different | |
| 6120. |
The most suitable filter for the removal of very small amount of precipitate from very large volumes of water is the __________ filter. |
| A. | vacuum |
| B. | sand |
| C. | plate & frame |
| D. | rotary |
| Answer» C. plate & frame | |
| 6121. |
Apron conveyors are used for |
| A. | heavy loads & short runs. |
| B. | small loads & long runs. |
| C. | heavy loads & long runs. |
| D. | none of these. |
| Answer» B. small loads & long runs. | |
| 6122. |
To get ultrafine particles, the equipment used is a |
| A. | ball mill |
| B. | rod mill |
| C. | hammer crusher |
| D. | fluid energy mill |
| Answer» E. | |
| 6123. |
Vacuum filter is most suitable for the |
| A. | removal of fines from liquid. |
| B. | liquids having high vapour pressure. |
| C. | liquids of very high viscosity. |
| D. | none of these. |
| Answer» E. | |
| 6124. |
The porosity of a compressible cake is |
| A. | minimum at the filter medium. |
| B. | minimum at the upstream face. |
| C. | maximum at the filter medium. |
| D. | same throughout the thickness of cake. |
| Answer» B. minimum at the upstream face. | |
| 6125. |
Which of the following conveyors cannot be recommended for transportation of abrasive materials ? |
| A. | Belt conveyor |
| B. | Apron conveyor |
| C. | Flight conveyor |
| D. | Chain conveyor |
| Answer» D. Chain conveyor | |
| 6126. |
Separation of materials into products based on the difference of their sizes is called |
| A. | sizing |
| B. | sorting |
| C. | classification |
| D. | flocculation |
| Answer» B. sorting | |
| 6127. |
Which of the following oxides is not present in hematite iron ore? |
| A. | Titanium oxide |
| B. | Calcium oxide |
| C. | Cobalt oxide |
| D. | Manganese oxide |
| Answer» D. Manganese oxide | |
| 6128. |
In closed circuit grinding as compared to open circuit grinding, the |
| A. | specific surface of product is more. |
| B. | product has lesser size uniformity. |
| C. | production rate at a given limiting size is lower. |
| D. | operation is economical. |
| Answer» E. | |
| 6129. |
With increase in the capacity of screens, the screen effectiveness |
| A. | remains unchanged |
| B. | increases |
| C. | decreases |
| D. | decreases exponentially |
| Answer» D. decreases exponentially | |
| 6130. |
As particle size is reduced |
| A. | screening becomes progressively more difficult. |
| B. | screening becomes progressively easier. |
| C. | capacity and effectiveness of the screen is increased. |
| D. | none of these. |
| Answer» B. screening becomes progressively easier. | |
| 6131. |
Rittinger number which designates the new surface prduced per unit of mechanical energy absorbed by the material being crushed, depends on the |
| A. | state or manner of application of the crushing force. |
| B. | ultimate strength of the material. |
| C. | elastic constant of the material. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 6132. |
Dust collection efficiency of electrostatic precipitator can be as high as 99.9%. Maximum temperature and pressure of dust laden gas that can be cleaned in an electrostatic precipitator is respectively. |
| A. | 200 C and 5 atm. |
| B. | 1000 C and 10 atm. |
| C. | 500 C and 50 atm. |
| D. | 1000 C and 500 atm. |
| Answer» C. 500 C and 50 atm. | |
| 6133. |
__________ balls capable of grinding the feed in a ball mill gives the maximum efficiency. |
| A. | Cast iron |
| B. | Minimum size |
| C. | Maximum size |
| D. | Elliptical |
| Answer» C. Maximum size | |
| 6134. |
The speed of a rotary drum vacuum filter may be about __________ rpm. |
| A. | 1 |
| B. | 50 |
| C. | 100 |
| D. | 500 |
| Answer» B. 50 | |
| 6135. |
In a ball mill, the volume occupied by the balls (when the mill is stopped) is about __________ percent of the volume of the mill. |
| A. | 35 |
| B. | 50 |
| C. | 70 |
| D. | 85 |
| Answer» C. 70 | |
| 6136. |
Separation of materials of the same density based on their sizes by using then-different rates of flow is called |
| A. | sorting |
| B. | sizing |
| C. | flocculation |
| D. | elutriation |
| Answer» C. flocculation | |
| 6137. |
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» B. mixer-extruder | |
| 6138. |
Agglomeration of individual particles into clusters (flocs) is called flocculation. To prevent flocculation, the most commonly used dispersing agents are |
| A. | carbonates |
| B. | sulphates |
| C. | silicates & phosphates |
| D. | bi-carbonates |
| Answer» D. bi-carbonates | |
| 6139. |
For a sphere falling in the constant drag co-efficient regime, its terminal velocity depends on its diameter (d) as |
| A. | d |
| B. | <span class="root">d</span> |
| C. | d |
| D. | <sup>2</sup> |
| E. | 1/d |
| Answer» D. <sup>2</sup> | |
| 6140. |
Cyclones are used primarily for separating |
| A. | solids |
| B. | solids from fluids |
| C. | liquids |
| D. | solids from solids |
| Answer» C. liquids | |
| 6141. |
There is practically no alternative/competitor to __________ in the beneficiation treatment of sulphide ores. |
| A. | classification |
| B. | tabling |
| C. | jigging |
| D. | froth floatation |
| Answer» E. | |
| 6142. |
Separation of isotopes is generally done using a/an __________ centrifuge. |
| A. | ultra |
| B. | disk-bowl |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» B. disk-bowl | |
| 6143. |
Temperature of the product during ultrafine grinding |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | may increase or decrease ; depends on the material being ground |
| Answer» B. decreases | |
| 6144. |
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 meshsize. |
| B. | dry chemicals. |
| C. | heavy tonnages of rocks or gravel. |
| D. | powdered food & granular materials. |
| Answer» D. powdered food & granular materials. | |
| 6145. |
Ore concentration by jigging is based on the difference in the __________ of the particles. |
| A. | specific gravities |
| B. | wettability |
| C. | shape |
| D. | none of these |
| Answer» B. wettability | |
| 6146. |
Size measurement of ultrafine particles can be best expressed in terms of |
| A. | centimetre |
| B. | screen size |
| C. | micron |
| D. | surface area per unit mass |
| Answer» E. | |
| 6147. |
Reduction ratio of crushers is the |
| A. | ratio of feed opening to discharge opening. |
| B. | ratio of discharge opening to feed opening. |
| C. | determining factor for minimum dia of the feed and the product. |
| D. | none of these. |
| Answer» B. ratio of discharge opening to feed opening. | |
| 6148. |
Which is a secondary crusher for a hard & tough stone ? |
| A. | Jaw crusher |
| B. | Cone crusher |
| C. | Impact crusher |
| D. | Toothed roll crusher |
| Answer» C. Impact crusher | |
| 6149. |
The reduction ratio for fine grinders is |
| A. | 5-10 |
| B. | 10-20 |
| C. | 20-40 |
| D. | as high as 100 |
| Answer» E. | |
| 6150. |
General mechanism of size reduction in intermediate and fine grinder is by |
| A. | cutting action. |
| B. | compression. |
| C. | compression and tearing. |
| D. | impact and attrition. |
| Answer» E. | |