MCQOPTIONS
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MCQOPTIONS
This section includes 362 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
The main size reduction operation in ultrafine grinders is_____________? |
| A. | Cutting |
| B. | Attrition |
| C. | Compression |
| D. | Impact |
| Answer» C. Compression | |
| 102. |
The main differentiation factor between tube mill and ball mill is the ___________________? |
| A. | Length to diameter ratio |
| B. | Size of the grinding media |
| C. | Final product size |
| D. | Operating speed |
| Answer» B. Size of the grinding media | |
| 103. |
The inlet pressure in a constant rate filtration____________________? |
| A. | Increases continuously |
| B. | Decreases gradually |
| C. | Remains constant |
| D. | None of these |
| Answer» B. Decreases gradually | |
| 104. |
The important dimensional group involved in the power requirement calculation in mixing operation is the _____________ number? |
| A. | Reynold’s |
| B. | Froude |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 105. |
The grinding in a hammer crusher takes place due to the_______________? |
| A. | Attrition |
| B. | Impact |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 106. |
The filtrate flow rate in constant pressure filtration___________________? |
| A. | Continuously increases |
| B. | Continuously decreases |
| C. | Remain constant throughout |
| D. | May increase or decrease; depends on the pressure |
| Answer» C. Remain constant throughout | |
| 107. |
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 |
| Answer» E. | |
| 108. |
The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond’s law) of the energy to grind the particles from a very large size to 50 μm is________________? |
| A. | 6.35 kWh/ton |
| B. | 9.0 kWh/ton |
| C. | 18 kWh/ton |
| D. | 25.4 kWh/ton |
| Answer» D. 25.4 kWh/ton | |
| 109. |
The energy consumed by a ball mill depends on__________________? |
| A. | Its speed |
| B. | Its ball load |
| C. | The density of the material being ground |
| D. | All A., B. and C. |
| Answer» E. | |
| 110. |
The crushed material received for separation is called feed or_________________? |
| A. | Tailing |
| B. | Heading |
| C. | Concentrate |
| D. | Middling |
| Answer» C. Concentrate | |
| 111. |
The critical speed of a trommel (N) is related to its dia D. as _____________________? |
| A. | N ∝ 1/√D |
| B. | N ∝ √D |
| C. | N ∝ D |
| D. | N ∝ 1/D |
| Answer» B. N ∝ √D | |
| 112. |
The controlling resistance in a rotary drum vacuum filter is the ________________ resistance? |
| A. | Piping |
| B. | Cake |
| C. | Filter medium |
| D. | None of these |
| Answer» C. Filter medium | |
| 113. |
The constants (Kb, Kr and Kk) used in the laws of crushing (i.e., Bond’s law, Rittinger’s law and Kick’s law) depend upon the_________________? |
| A. | Feed material |
| B. | Type of crushing machine |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 114. |
The capacity of a pneumatic conveying system depends upon the ______________________? |
| A. | Bulk density of materials |
| B. | Pressure of the conveying air |
| C. | Diameter of the conveying line |
| D. | All A., B. and C. |
| Answer» E. | |
| 115. |
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.? |
| A. | Same as |
| B. | 2.5 times |
| C. | 5 times |
| D. | 10 times |
| Answer» C. 5 times | |
| 116. |
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 |
| Answer» B. Thickness | |
| 117. |
The capacity of a classifier in ‘tons of solid/hr’ is given by (where, A = cross-sectional area in m2, V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3)_________________? |
| A. | 3.6 AVS.ρ |
| B. | 3.6 A.V.ρ |
| C. | 3.6 A.S. ρ |
| D. | 3.6 AVS/ρ |
| Answer» B. 3.6 A.V.ρ | |
| 118. |
The cake resistance increases steadily with the time of filtration in a plate and frame filter employing constant ______________ filtration? |
| A. | Rate |
| B. | Pressure |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 119. |
The basic filtration equation is given as dt/dV = (μ/A ΔP). [(α .CV/A) + Rm], where, V is volume of the filtrate; A is the filtration area, a is specific cake resistance, μ 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 | |
| 120. |
Screen capacity is not a function of__________________? |
| A. | Its openings size |
| B. | Screening mechanism |
| C. | Screening surface |
| D. | Atmospheric humidity |
| Answer» E. | |
| 121. |
Screw conveyors are________________? |
| A. | Run at very high rpm |
| B. | Suitable for sticky materials |
| C. | Suitable for highly abrasive materials |
| D. | All A., B. and C. |
| Answer» C. Suitable for highly abrasive materials | |
| 122. |
Screen efficiency is______________________? |
| A. | Recovery/rejection |
| B. | Recovery |
| C. | Rejection |
| D. | None of these |
| Answer» E. | |
| 123. |
Screen capacity is proportional to (where, S = screen aperture)____________________? |
| A. | S |
| B. | 1/S |
| C. | S2 |
| D. | √S |
| Answer» B. 1/S | |
| 124. |
Screen capacity is expressed in terms of____________________? |
| A. | tons/hr |
| B. | tons/ft2 |
| C. | Both A. & B. |
| D. | tons/hr-ft2 |
| Answer» E. | |
| 125. |
Sauter mean diameter is the same as the ______________ mean diameter? |
| A. | Mass |
| B. | Arithmetic |
| C. | Volume-surface |
| D. | Geometric |
| Answer» D. Geometric | |
| 126. |
Run of mine (ROM) coal is crushed by a _________________________ for use in domestic ovens? |
| A. | Jaw crusher |
| B. | Hammer crusher |
| C. | Ball mill |
| D. | Tube mill |
| Answer» C. Ball mill | |
| 127. |
Rod mills employed for grinding_________________? |
| A. | Employ a steel shell having L/D ratio of 1.5 to 3.0 |
| B. | Is useful for handling sticky materials |
| C. | Employ steel rods of 2-12 cms diameter extending over full length of the mill |
| D. | All A , B & C |
| Answer» E. | |
| 128. |
Rittinger’s number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger’s number of a material indicates its________________? |
| A. | Easier grindability |
| B. | Poor grindability |
| C. | High power consumption in grinding |
| D. | None of these |
| Answer» B. Poor grindability | |
| 129. |
Rittinger’s crushing law states that_____________________? |
| A. | Work required to form a particle of any size is proportional to the square of the surface to volume ratio of the product |
| B. | Work required to form a particle of a particular size is proportional to the square root of the surface to volume ratio of the product |
| C. | Work required in crushing is proportional to the new surface created |
| D. | For a given machine and feed, crushing efficiency is dependent on the size of the feed & product |
| Answer» D. For a given machine and feed, crushing efficiency is dependent on the size of the feed & product | |
| 130. |
Rittinger number which designates the new surface produced 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. | |
| 131. |
Ribbon blenders are exclusively meant for __________________? |
| A. | Blending miscible liquids |
| B. | Non-flowing powder and thin pastes |
| C. | Bath mixing |
| D. | Continuous mixing |
| Answer» C. Bath mixing | |
| 132. |
Removal of activated carbon from glycerine is done by _________________? |
| A. | Plate and frame filter |
| B. | Rotary vacuum filter |
| C. | Batch basket centrifuge |
| D. | None of these |
| Answer» B. Rotary vacuum filter | |
| 133. |
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 | |
| 134. |
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» D. Powdered food & granular materials | |
| 135. |
Reciprocal of sphericity is termed as the________________? |
| A. | Specific surface ratio |
| B. | Shape factor |
| C. | Sauter diameter |
| D. | Surface area per unit mass |
| Answer» C. Sauter diameter | |
| 136. |
Raw materials are charged in the iron blast furnace using____________________? |
| A. | Bucket elevator |
| B. | Skip hoist |
| C. | Screw conveyor |
| D. | None of these |
| Answer» C. Screw conveyor | |
| 137. |
Range of compressibility co-efficient of the commercial compressible cake obtained in filtration operation is_____________________? |
| A. | 0.01 to 0.1 |
| B. | 0.1 to 0.3 |
| C. | 0.2 to 0.8 |
| D. | 0.2 to 0.4 |
| Answer» D. 0.2 to 0.4 | |
| 138. |
Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of ____________ mm? |
| A. | 0.007 |
| B. | 0.30 |
| C. | 50 |
| D. | 0.014 |
| Answer» C. 50 | |
| 139. |
Production rate _____________ with increased fineness, with a given energy input to the size reduction machine? |
| A. | Decreases |
| B. | Increases |
| C. | Remains unchanged |
| D. | May increase or decrease; depends on the machine |
| Answer» B. Increases | |
| 140. |
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 |
| Answer» D. 1/D2.5 | |
| 141. |
Power consumption during turbulent flow in agitation tank is proportional to the ______________ of the liquid? |
| A. | Viscosity |
| B. | Thermal conductivity |
| C. | Surface tension |
| D. | Density |
| Answer» E. | |
| 142. |
Pine oil and Cresylic acid are used as ______________ in the froth floatation process? |
| A. | Frother |
| B. | Collector |
| C. | Depressor |
| D. | Conditioner |
| Answer» B. Collector | |
| 143. |
Pine oil used in froth floatation technique acts as a/an_____________________? |
| A. | Collector |
| B. | Modifier |
| C. | Frother |
| D. | Activator |
| Answer» D. Activator | |
| 144. |
Pick out the wrong statement pertaining to the roll crushers? |
| A. | Maximum feed size determines the required roll diameter |
| B. | For hard material’s crushing, the reduction ratio should not exceed 4 |
| C. | Both the rolls run necessarily at the same speed |
| D. | Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced |
| Answer» D. Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced | |
| 145. |
Pick out the wrong statement pertaining to the turbine agitator ? |
| A. | Recommended peripheral speed for the turbine agitator is 200-250 metres/minute |
| B. | Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow |
| C. | Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with |
| D. | Turbine agitator should be located at a height not less than one agitator diameter length from the bottom. If the depth of liquid in the tank is more |
| Answer» C. Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with | |
| 146. |
Pick out the material having minimum Rittinger’s number? |
| A. | Calcite |
| B. | Pyrite |
| C. | Quartz |
| D. | Galena |
| Answer» D. Galena | |
| 147. |
Percentage of drum submerged in the slurry in case of rotary drum filter is ________________? |
| A. | 3 |
| B. | 30 |
| C. | 85 |
| D. | 25 |
| Answer» C. 85 | |
| 148. |
Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of__________________? |
| A. | Bronze |
| B. | Stainless steel |
| C. | Flint or porcelain |
| D. | Concrete |
| Answer» D. Concrete | |
| 149. |
Particle size range in which dust catcher (gravity settling chamber) works most effectively and efficiently is ______________ microns? |
| A. | < 5 |
| B. | 10 to 25 |
| C. | < 74 |
| D. | > 1000 |
| Answer» D. > 1000 | |
| 150. |
Paddle agitator_________________? |
| A. | Is suitable for mixing low viscosity liquids |
| B. | Produces axial flow |
| C. | Moves at very high speed |
| D. | None of these |
| Answer» B. Produces axial flow | |