Description : 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
Last Answer : (A) Metalliferous ores
Description : 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
Last Answer : (C) Flint or porcelain
Description : Pick out the correct statement. (A) Noise from ball mills can be dealt with by fibre glass lined enclosures (B) Noise from vibrating chutes can be reduced by lining the metallic chute with rubber (C) Noise ... cloth conveyor belts and rubber/plastic covered metallic rollers (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Size reduction of asbestos and mica is done by (A) Hammer mills (B) Rod mills (C) Gyratory crushers (D) Crushing rolls
Last Answer : (A) Hammer mills
Description : A tube mill as compared to a ball mill (A) Employs smaller balls (B) Gives finer size reduction but consumes more power (C) Has larger length/diameter ratio (>2 as compared to 1 for ball mill) (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Which of the following is not a dielectric material? (A) Cotton, silk and paper (B) Asbestos, glass, porcelain and mica (C) Rubber and polymeric resins (D) All refractory materials
Last Answer : Option C
Description : Balls for ball mills are never made of (A) Forged/cast steel (B) Lead (C) Cast iron (D) Alloy steel
Last Answer : (B) Lead
Description : For efficient grinding, ball mills must be operated (A) At a speed less than the critical speed (B) At a speed more than the critical speed (C) At a speed equal to the critical speed (D) With minimum possible small balls
Last Answer : (A) At a speed less than the critical speed
Description : 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)
Last Answer : (D) Both (B) and (C)
Description : Pick out the wrong statement. (A) Cumulative analysis for determining surface area is preferred over differential analysis, because of the assumption that "all particles in a simple fraction equal in size" is ... throwing of the balls through the air to the toe of the heap is called 'cataracting'
Last Answer : (C) Capacity of crusher in choke feeding is increased
Description : __________ mills fall in the category of tumbling mills, (A) Ball and pebble (B) Rod and tube (C) Compartment (D) All (A), (B) & (C
Last Answer : (D) All (A), (B) & (C
Description : Stamp mills are generally used for crushing (A) Iron ores (B) Gold ores (C) Talc (D) Diamond
Last Answer : (B) Gold ores
Description : Limestone is normally crushed in a (A) Roll crusher (B) Hammer crusher (C) Ball mill (D) Tube mill
Last Answer : (B) Hammer crusher
Description : Out of the following size reduction equipments, the maximum feed size can be accepted by the (A) Tube mill (B) Ball mill (C) Jaw crusher (D) Jet pulveriser
Last Answer : (C) Jaw crusher
Description : Pick out the wrong statement: (A) Magnetic separation method can be employed to treat both dry & wet ores (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed ... ) Gyratory crusher is used for coarse crushing (D) Screens are of stationary, moving and vibratory types
Last Answer : (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed size to the maximum product size
Description : Size reduction does not occur due to compression in case of (A) Rod mills (B) Gyratory crushers (C) Jaw crushers (D) Smooth roll crushers
Last Answer : (A) Rod mills
Description : Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression
Last Answer : (B) Attrition
Description : Which of the following size reduction equipments employs mainly attrition for ultrafine grinding? (A) Jet mills (B) Fluid energy mill (C) Micronizer (D) All (A), (B) and (C)
Description : Tube mill compared to ball mill (A) Produces finer products (B) Is long in comparison with its diameter (C) Uses smaller balls (D) All (A), (B) & (C)
Description : A tube mill compared to a ball mill (A) Has a higher length/diameter ratio (B) Produces a coarser product (C) Has a higher diameter/length ratio (D) Uses much larger balls
Last Answer : (A) Has a higher length/diameter ratio
Description : Workers working in __________ industry are most prone to white lung cancer. (A) Coal mining (B) Limestone mining (C) Textile (D) Asbestos
Last Answer : (C) Textile
Description : 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
Last Answer : (B) Cage mill
Description : When should metallic framework not be contaminated during the fabrication of a porcelain fused to metal crown: A. Between bisque stage and glazing stage B. Between preheat and opaque stages C. Between opaque and bisque stages D. Between one opaque and two opaque stages
Last Answer : B. Between preheat and opaque stages
Description : Which of the following materials may prove unsuitable for handling acetic acid (glacial & anhydrous) at 40°C? (A) Silicone rubber, teflon, porcelain and wood (B) Nickel, monel, stainless steel and graphite (C) Aluminium, copper, high silicon iron (D) Brass, cast iron, mild steel and tin
Last Answer : (D) Brass, cast iron, mild steel and tin
Description : H2SO4 (< 50% concentration) is corrosive to (A) Aluminium, mild steel, stainless steel, concrete & tin (B) Copper, cast iron & high silicon iron (14% Si) (C) Rubber (butyl and hard), silicone rubber & Teflon (D) Glass, graphite, porcelain & stoneware
Last Answer : (A) Aluminium, mild steel, stainless steel, concrete & tin
Description : 100% H2SO4 at 30°C can't be stored in a vessel made/lined with (A) Cast iron and high silicon iron (B) Mild steel and stainless steel (C) Aluminium, tin and rubber (D) Teflon, glass and porcelain
Last Answer : (C) Aluminium, tin and rubber
Description : The commodity which accounts for the maximum volume of goods transported by the railways in India is (a) iron and steel (b) coal (c) mineral oil (d) metallic ores (other than iron ore)
Last Answer : Ans: (b)
Description : Metallic elements are often obtained from ores. Name the metallic element which is produced from the ore Bauxite.
Last Answer : ANSWER: ALUMINUM
Description : __________ 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
Last Answer : (B) Minimum size
Description : Reverberatory furnace is used for (A) Roasting/reduction of ores (B) Annealing steel coil (C) Heating air (D) Steel melting
Last Answer : (A) Roasting/reduction of ores
Description : What is the minimal labial reduction for porcelain metal crowns: A. 1mm B. 1.5mm C. 0.5mm
Last Answer : B. 1.5mm
Description : The minimal labial tooth reduction for satisfactory aesthetics with porcelain fused to metal crown is, A. 1mm B. The full thickness of enamel C. 1.5 mm D. 2.5mm E. One third of the dentine thickness
Last Answer : C. 1.5 mm
Description : Size reduction of __________ is accomplished in steam heated rollers and roll crushers. (A) Resins (B) Gums (C) Hard rubber (D) Waxes
Last Answer : (C) Hard rubber
Description : _________ baffles are provided in ball mills. (A) Horizontal (B) No (C) Only two (D) None of these
Last Answer : (A) Horizontal
Description : Basic slag is not ground in (A) Jaw crushers (B) Ball mills
Last Answer : (A) Jaw crushers
Description : Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed? (A) ... of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills
Last Answer : (D) Dry grinding of large particles in un-baffed mills
Description : Which of the following is not a cutting machine? (A) Dicers (B) Knife cutters (C) Slitters (D) Tube mills
Last Answer : (D) Tube mills
Description : Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines? (A) Compartment mill (B) Rod mill (C) Pebble mill (D) Tube mill
Last Answer : (B) Rod mill
Description : Statement -1 : Ores are generally converted into oxides , prior to reduction . Statement- 2 : Metal oxides can be easily reduced .
Last Answer : Statement -1 : Ores are generally converted into oxides , prior to reduction . Statement- 2 : Metal oxides ... -1 : is false , statement-2 : is true
Description : Statement-1: Auto reduction of ores is used for cinnabar, copper glance and Galena ores Statement-2:The sulphide ores of these metals react with their
Last Answer : Statement-1: Auto reduction of ores is used for cinnabar, copper glance and Galena ores Statement-2: ... Statement-1 is false but Statement -2 is true
Description : Which of the following faction is of no significance for roasting sulphide ores to the oxide and not subjecting the sulphide ores in carbon reduction
Last Answer : Which of the following faction is of no significance for roasting sulphide ores to the oxide and ... are thermodynamically more stable than `CS_(2)`
Description : Which of the following is the primary reason for adding calcium carbonate to the reduction process of iron oxide ores ? The calcium carbonate: w) acts as an oxidizing agent x) removes silicate waste products y) acts as a reducing agent z) removes sulfur waste products
Last Answer : ANSWER: X -- REMOVES SILICATE WASTE PRODUCTS
Description : In a cartridge-type fuse, the metal element is contained in a ___________________. A. porcelain window B. thermal cut out C. fiber tube D. flasher device
Last Answer : Answer: C
Description : Which of the following is a good conductor of heat but a bad conductor of electricity? (1) Celluloid (2) Rubber (3) Asbestos (4) Mica
Last Answer : (4) Mica Explanation: Good conductors of heat are good conductors of electricity. Mica is an exception which although being a good conductor of heat and a bad conductor of electricity. It is commonly ... to assist in the transfer of the generated heat to the heat sink or chassis for dissipation.
Description : Which of the following types of insulation will begin to deteriorate FIRST as a result of the heat generated in the conductor it surrounds? A. Varnished cloth B. Rubber C. Silicon D. Asbestos
Last Answer : Answer: B
Description : Which of the following statements best describes the material known as varnished cambric? A. Felted asbestos sealed with varnish. B. Cotton cloth coated with insulating varnish. C. Rubber ... Paper impregnated with mineral oil, specially wrapped with nonmetallic tape, and coated with varnish.
Description : Which of the following is a good conductor of heat but a bad conductor of electricity ? (1) Celluloid (2) Rubber (3) Asbestos (4) Mica
Last Answer : Mica
Description : Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately? (A) Rittinger's law (B) Kick's law (C) Bond's law (D) None of these
Last Answer : (A) Rittinger's law
Description : For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a (A) Buhrstone mill (B) Ball mill (C) Crushing rolls (D) Hammer mill
Last Answer : (A) Buhrstone mill
Description : Arrange the following size reduction equipment in the decreasing order of the average particle size produced by each of them. (A) Jaw crusher, Ball mill, Fluid energy mill (B) Ball mill, Jaw crusher, Fluid ... C) Fluid energy mill, Jaw crusher, Ball mill (D) Fluid energy mill, Ball mill, Jaw crusher
Last Answer : (A) Jaw crusher, Ball mill, Fluid energy mill