Description : Pick out the correct statement. (A) Plastic chips are called non-cohesive solids (B) Kick's crushing law is, P/m = K . ln (D̅sa /Ds̅b ) (C) Communition is a generic term for size enlargement ... per ton of product, such that 80% of it passes through a 200 mesh screen, is called 'Work index'
Last Answer : (B) Kick's crushing law is, P/m = K . ln (D̅sa /Ds̅b )
Description : The work index in Bond's law for crushing of solids has the following dimensions (A) No units (dimensionless) (B) kWh/ton (C) kW/ton (D) kWh.m1/2 /ton
Last Answer : (B) kWh/ton
Description : The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel. (A) 60 - 100 (B) 400 - 700 (C) 1200 -1500 (D) 2000 - 2300
Last Answer : (B) 400 - 700
Description : 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
Last Answer : (C) 18 kWh/ton
Description : Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity. (A) 300 (B) 800 (C) 1400 (D) 2000
Last Answer : (C) 1400
Description : Work index is defined as the (A) Gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of the product passes through a 100 micron screen (B) Energy needed to crush ... of the product passes a 200 mesh screen (D) Energy needed to crush one ton of feed to 100 microns
Last Answer : (A) Gross energy (kWh/ton of feed) needed to reduce very large feed to such a size that 80% of the product passes through a 100 micron screen
Description : Crushing efficiency of a machine ranges between __________ percent. (A) 0.1 to 2 (B) 5 to 10 (C) 20 to 25
Last Answer : (A) 0.1 to 2
Description : In a 100 TPD Sponge Iron plant, the sponge iron is fed to the Induction melting furnace, producing molten steel at 88% yield. The Energy consumption details are as follows: Coal Consumption : 130 ... molten steel (product). 3. Total Energy Consumption of Plant in Tons of Oil Equivalent (TOE )
Last Answer : a) Specific Energy Consumption of Induction Melting Furnace Molten Steel Production from the Induction melting furnace per day = 100 x 88/100 = 88 TPD Total Energy Consumption of the Plant = 82400 kWh ... mark c) Total Energy consumption of Plant in ToE = 655864000/107 = 65.586 ToE
Description : Which one is not an energy consumption benchmark parameter? a) kcal/kWh of electricity generated b) kg/ oC. c) kW/ton of refrigeration d) kWh/kg of yarn
Last Answer : b) kg/ oC.
Description : 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 ... ratio and differential roll speed affect production rate & energy consumed per unit of surface produced
Last Answer : (C) Both the rolls run necessarily at the same speed
Description : Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should ... to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34
Last Answer : (C) 1.34
Description : 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)
Last Answer : (D) All (A), (B) and (C)
Description : Production of one ton of cement requires about __________ tons of limestone. (A) 0.6 (B) 1.2 (C) 2.2 (D) 3.8
Last Answer : (B) 1.2
Description : 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)
Description : Thermal equivalent of electrical power in practical calculation is __________ kcal/kWh. (A) 746 (B) 3000 (C) 1000 (D) 550
Last Answer : (B) 3000
Description : A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpm Head = 8 metres Flow = 1000 litres/minutes. If its speed is halved, the power consumed now will be __________ hp. (A) 0.5 (B) 2 (C) 4 (D) 1
Last Answer : (A) 0.5
Description : 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)
Last Answer : (C) Both (A) & (B)
Description : Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of ... a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas
Last Answer : (C) Size enlargement (opposite of size reduction) is not a mechanical operation
Description : 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 ... V.W.Dr.ρ (B) 3.6 V.W. ρ (C) 3.6 W.Dr.ρ (D) 3.6 V.W.Dr/ρ
Last Answer : (A) 3.6 V.W.Dr.ρ
Description : Production of one ton of dry paper pulp requires about __________ tons of bamboo or wood. (A) 1 (B) 2.5 (C) 5 (D) 10
Last Answer : (B) 2.5
Description : General crushing equation is given by d(P/m) = -K (dD̅S /D̅ n S ). Bond's crushing law is obtained by solving this equation for n = __________ and feed of infinite size. (A) 1 (B) 1.5 (C) 2 (D) 2.5
Last Answer : (B) 1.5
Description : Austenitic manganese steel used for making jaws of crushing machines contains about __________ percent manganese. (A) 1.5-2 (B) 3.5-4.5 (C) 7-9 (D) 12-14
Last Answer : (D) 12-14
Description : . Kick's law assumes that the energy required for size reduction is proportional to the logarithm of the ratio between the initial and the final diameters. The unit of Kick's constant is (A) kW. sec/kg (B) kWh/kg (C) kWh/sec. kg (D) kg/sec
Last Answer : (A) kW. sec/kg
Description : Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3 /ton of dry coal. (A) 60 (B) 160 (C) 500 (D) 750
Last Answer : (B) 160
Description : Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around __________ Nm3 . (A) 30 (B) 300 (C) 3,000 (D) 30,000
Last Answer : (B) 300
Description : Yield of blast furnace gas is about __________ Nm3 /ton of pig iron. (A) 300 (B) 2000 (C) 5000 (D) 10000
Last Answer : (B) 2000
Description : Gas yield in the Kopper-Totzek coal gasifier is about __________ Nm3 /ton coal (ash = 35%). (A) 150 (B) 1500 (C) 3500 (D) 5000
Last Answer : (C) 3500
Description : Out of the following substances, one ton of __________ will store the maximum heat for a rise of 30°C in temperature. (A) Steel (B) Lignite (C) Water (D) Lime stone
Last Answer : (C) Water
Description : The cooling rate required to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours is __________ BTU/hr. (A) 100 (B) 200 (C) 1000 (D) 2000
Last Answer : (B) 200
Description : Crushing of mineral particles is accomplished in a 'cage mill', when one or more alloy steel bars are revolved in opposite directions. It is a type of __________ mill. (A) Impact (B) Roll (C) Vibratory (D) None of these
Last Answer : (A) Impact
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 : Gravity stamp mill is meant for the __________ crushing. (A) Primary (B) Intermediate (C) Fine (D) Ultrafine
Last Answer : (C) Fine
Description : 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
Description : In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the __________ crushing. (A) Primary (B) Secondary (C) Fine (D) Ultrafine
Last Answer : (B) Secondary
Description : In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing. (A) Secondary (B) Fine (C) Primary (D) Ultrafine
Last Answer : (C) Primary
Description : or Indian standard (IS) screens, the mesh number is equal to its aperture size expressed to the nearest deca-micron (0.01 mm). Aperture width of IS screen of mesh number 50 will be approximately __________ microns. (A) 5 (B) 50 (C) 500 (D) 5000
Last Answer : (C) 500
Description : Liquid diffusivity is of the order of __________ cm2 /second. (A) 0.01 (B) 0.1 (C) 10 -5 to 10 -6 (D) > 1
Last Answer : (C) 10 -5 to 10
Description : Maximum permissible residual chlorine in treated water should be __________ mg/litre. (A) 0.001 to 0.01 (B) 0.2 to 0.3 (C) 2 to 3 (D) 5 to 10
Last Answer : (B) 0.2 to 0.3
Description : Maximum change in the hardness of martensite occurs in the carbon content range of __________ percent in steel. (A) 0.01 to 0.10 (B) 0.2 to 0.4 (C) 0.5 to 0.7 (D) 0.8 to 1.0
Last Answer : (B) 0.2 to 0.4
Description : A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of ... and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5
Last Answer : (B) 0.1
Description : Water filtration rate in a rapid sand filter ranges from __________ kilolitres/m2 /hr. (A) 0.1 to 1 (B) 3 to 6 (C) 10 to 15 (D) 15 to 20
Last Answer : (B) 3 to 6
Description : Carbon content in steel is __________ percent. (A) 0.1-2 (B) 4-6 (C) 2-4 (D) 0.001-0.01
Last Answer : (A) 0.1-2
Description : A fluid (µ/ρ) = 0.01 cm2 /sec is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec. (A) 7 (B) 700 (C) 7000 (D) 630
Last Answer : (A) 7
Description : Rotary vacuum pumps can reduce the absolute pressure to as low as __________ mm Hg. (A) 1 (B) 0.1 (C) 0.01 (D) 0.001
Last Answer : (C) 0.01
Description : Brownian movement is prominent in the particle size range of __________ microns in case of settling of a particle in a fluid. (A) 2 to 3 (B) 0.01 to 0.10 (C) 200 to 300 (D) 100 to 1000
Last Answer : A) 2 to 3
Description : Dose of chlorine for disinfection of water is about __________ mg/litre of water. (A) 0.01 (B) 0.1 (C) 0.3 (D) 1
Last Answer : (D) 1
Description : When the concentration of SO2 in air is greater than __________ ppm, it gives a pungent smell. (A) 0.01 (B) 0.1 (C) 1 (D) 4
Last Answer : (D) 4
Description : The difference in one unit of Rockwell hardness number corresponds to a difference in the depth of indentation of __________ mm. (A) 0.001 (B) 0.01 (C) 0.002 (D) 0.02
Last Answer : Option C
Description : India receives amount of solar energy each year a. 5×1010 kWh/year. c) 5×1015 kWh/year b. 4×1015 kWh/year. d) 5×1010 kWh/year
Last Answer : 5×1015 kWh/year
Description : Granite is not suitable for ordinary building purpose because (A) It cannot be polished (B) It is not a fire proof material (C) It is costly (D) It has less crushing strength
Last Answer : Answer: Option C