Description : Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool
Last Answer : (D) 85% magnesia cement and glass wool
Description : Chlorination of benzene is done to produce benzene hexachloride (a pesticide) in a photochemical reactor lined with (A) Karbate (B) Lead or glass (C) Fireclay bricks (D) PVC
Last Answer : (B) Lead or glass
Description : Ceramic recuperators are generally made of (A) Silicon carbide (B) Calcium carbide (C) Fireclay bricks (D) High alumina bricks
Last Answer : (A) Silicon carbide
Description : Beehive coke ovens are made of __________ bricks. (A) Silica (B) Fireclay (C) Silicon carbide (D) Corundum
Last Answer : (A) Silica
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 : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number
Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads
Description : Pick out the wrong statement. (A) Seam welding, projection welding & spot welding are the classification of electrical resistance welding (B) Electrode tip in spot welding is of copper and the ... joined are overlapped and placed between two electrodes (D) Mild steel sheet cannot be spot welded
Last Answer : (D) Mild steel sheet cannot be spot welded
Description : Pot furnace which is either regenerative or recuperative, is used in the manufacture of (A) Glass (B) Stainless steel (C) Potteries (D) Refractory bricks
Last Answer : (A) Glass
Description : Rotary kilns in cement industry are lined with _________bricks. (A) Fireclay (B) Silica (C) Lead (D) High alumina & high magnesia
Last Answer : (D) High alumina & high magnesia
Description : Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m. k) of 15 mm diameter exposed to air (h = 20W/m2.k), when the insulation thickness is __________ mm. (A) 15 (B) 25 (C) 10 (D) 30
Last Answer : (B) 25
Description : he pressure drop per unit length of pipe incurred by a fluid 'X' flowing through pipe is Δp. If another fluid 'Y' having both the specific gravity & density just double of that of fluid 'X', flows through the same pipe ... then the pressure drop in this case will be (A) Δp (B) 2Δp (C) Δp 2 (D) Δp/2
Last Answer : (B) 2Δp
Description : The coefficient of static friction will have the highest value in case of a.Mild steel and mild steel b.Mild steel and copper c.Cast iron and steel d.Rope and wood e.Any of the above loctions
Last Answer : d. Rope and wood
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 : The disc is made from of 5mm-10mm thickness. a) Heat treated steel b) Case hardened steel c) Stainless steel d) High speed steel
Last Answer : Heat treated steel
Description : For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) ... the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these
Last Answer : (C) Increases the overall heat transfer coefficient
Description : Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for ... a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature
Last Answer : (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs
Description : Resistance to heat flow by conduction is proportional to (where, t & ρ are thickness & density of the material respectively and A = area normal tothe direction of heat flow.) (A) t (B) 1/ρ (C) 1/A (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
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 : Choose the most important factor on which the heat conducted through a wall in a unit time will depend on? (A) Thickness of the wall (B) Area of the wall perpendicular to heat flow (C) Material of the wall (D) Temperature difference between the two surfaces of the wall
Last Answer : (D) Temperature difference between the two surfaces of the wall
Description : Conductance is given by (where, x = thickness, A = heat flow area, K = thermal conductivity.) (A) x/KA (B) KA/x (C) K/Ax (D) A/Kx
Last Answer : (B) KA/x
Description : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube
Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K
Description : The biggest point sources of waste heat originate from ....... production. a) Steel or Brass b) Copper or Glass c) Steel or Glass d) Steel or Copper
Last Answer : Steel or Glass
Description : The refractory lining of the bottom in a basic electric arc furnace is made of (A) Silica (B) Alumina (C) Magnesia (D) Fireclay
Last Answer : Option C
Description : Minimum thickness of wall where single Flemish bond can be used is (A) Half brick thick (B) One brick thick (C) One and a half bricks thick (D) Two bricks thick
Last Answer : Answer: Option C
Description : Herringbone bond is used for (A) Walls having thickness more than 4 bricks (B) Architectural finish to the face work (C) Ornamental panels in brick flooring (D) All the above
Last Answer : Answer: Option D
Description : A composite flat wall of a furnace is made of two materials 'A' and 'B'. The thermal conductivity of 'A' is twice of that of material 'B', while the thickness of layer of 'A' is half that of B. If the temperature ... drop (in °K) across the layer of material 'A' is (A) 125 (B) 133 (C) 150 (D) 160
Last Answer : (D) 160
Description : One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is (A) 100 (B) 900 (C) 9000 (D) 10000
Last Answer : (D) 10000
Description : Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per m2 of steel strip. (A) 5-10 (B) 1000-1500 (C) 120-500 (D) 1500-3000
Description : Pick out the correct statement. (A) For identical gas flow rates, less pressure drop occurs through a plate tower than through a packed tower (B) Plate column can handle greater liquid loads without flooding than packed ... duty, plate columns weigh less than packed columns (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Thermometer bulb & capillary in case of mercury filled pressure spring expansion thermometer is normally made of __________ as mercury does not amalgamate with it. (A) Copper (B) Copper alloys (C) Stainless steel (D) Monel
Last Answer : (C) Stainless steel
Description : In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid (A) Is inversely proportional to the resistance across which the drop occurs (B) And the wall are proportional to individual resistances (C) And the wall is not related (D) None of these
Last Answer : (B) And the wall are proportional to individual resistances
Description : In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C. (A) 20 (B) 60 (C) 120 (D) ∞
Last Answer : (D) ∞
Description : The fermenter used for the production of ethyl alcohol from molasses is made of (A) Wood (B) Concrete (C) Copper bearing steel (D) Porcelain
Last Answer : (C) Copper bearing steel
Description : Copper is dissolved from its ore by H2SO4 in a percolation tank made of (A) Wood (B) Stainless steel (C) Reinforced concrete lined with lead (D) High silicon iron (14% Si)
Last Answer : (C) Reinforced concrete lined with lead
Description : Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is ... The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same
Last Answer : (A) Heat transfer by radiation cannot occur across an absolute volume
Description : For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would (A) Decrease (B) Increase (C) First decrease and then increase (D) First increase and then decrease
Last Answer : (D) First increase and then decrease
Description : In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will (A) Decrease gradually (B) Increase gradually (C) Increase rapidly (D) Remain constant
Last Answer : (B) Increase gradually
Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C
Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C
Description : . If a single tube pass heat exchanger is converted to two pass, then for the same flow rate, the pressure drop per unit length in tube side will (A) Increase by 1.8 times (B) Decrease by 2 2 (C) Increase by 2 16 (D) Remain unchanged
Last Answer : (C) Increase by 2 16
Description : To reduce the tube side pressure drop for the same flow rate, the heat exchanger recommended is (A) 1-2 heat exchanger (B) 1-1 heat exchanger (C) 3-2 heat exchanger (D) 2-4 heat exchanger
Last Answer : (B) 1-1 heat exchanger
Description : Pick out the wrong statement. (A) Copper is the metal having the highest electronic conductivity (B) Hardenability & Weldability of metals are inversely related (C) Covalent bonding formed by ... all semiconductor materials (D) Glass transition temperature applies to 'polymers' but not to 'glasses'
Last Answer : Option A
Description : Pick out the wrong statement. (A) Reciprocal of the resistance to heat flow is called thermal conductance (B) Unit of thermal conductance is W/°K (C) Thermal conductance of a wall of thickness 'L', thermal conductivity 'k' and heat flow area 'A' is kL/A (D) None of these
Last Answer : (C) Thermal conductance of a wall of thickness 'L', thermal conductivity 'k' and heat flow area 'A' is kL/A
Description : For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ
Last Answer : (B) 1/μ
Description : Pick out the wrong statement. (A) For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1 (B) For calculating forces and ... Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
Last Answer : Option B
Description : case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is (A) More (B) Less (C) Equal (D) Much more
Description : SO3 is absorbed using H2SO4 in a (A) Cast iron packed tower (B) Stainless steel plate tower (C) Packed steel tower lined with acid proof bricks (D) None of these
Last Answer : (C) Packed steel tower lined with acid proof bricks
Description : Rotary driers are generally made of (A) Cast iron (B) Mild steel (C) High silicon iron (14% Si) (D) Tin lined with refractory bricks
Last Answer : (B) Mild steel
Description : Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with (A) Acidic refractory (B) Rubber (C) Karbate (D) Lead or acid proof bricks
Last Answer : (A) Acidic refractory
Description : Sulphuric acid is mixed with ground phosphate rock (to produce phosphoric acid) in a steel digestor lined with (A) Acidic refractory (B) Rubber (C) Karbate (D) Lead or acid-proof bricks
Last Answer : (D) Lead or acid-proof bricks
Description : In transmission lines the crossarms are made of (a) copper (b) wood (c) R.C.C. (d) steel
Last Answer : (d) steel