Description : Nitriding is a process of heating steel in atmosphere of :
Last Answer : Nitriding is a process of heating steel in atmosphere of : A. ammonia B. oxygen C. carbondioxide D. air
Description : Pick out the wrong statement. (A) Both annealing and normalising release the internal stresses of the material besides improving the mechanical properties (B) Low carbon steel does not respond to ... are also used for surface hardening (D) Martempering of a material is a hardening process
Last Answer : Option C
Description : The purpose of nitriding the steel is to (A) Harden its surface (B) Soften its surface (C) Improve its reliability (D) None of these
Last Answer : (A) Harden its surface
Description : Nitriding of a steel part does not increase its (A) Grain size (B) Fatigue limit (C) Surface hardness (D) Wear resistance
Last Answer : Option B
Description : Nitriding of steel is a process for (A) Case hardening (B) Spheroidising (C) Normalising (D) Annealing
Last Answer : (A) Case hardening
Description : Nitriding of steel is done (in electric furnace) at __________ °C. (A) 510 (B) 1720 (C) 2210 (D) 910
Last Answer : (A) 510
Description : Volume of `N_(2)` at 1 atm, 273 K required to form a monolayer on the surface of iron catalyst is `8.15ml//gm` of the adsorbent. What will be the surf
Last Answer : Volume of `N_(2)` at 1 atm, 273 K required to form a monolayer on the surface of iron catalyst is `8.15ml//gm` ... C. `39 m^(2)//g` D. `22400 cm^(2)`
Description : While normal carburising and nitriding surface treatments increase fatigue strength, excessive treatment may decrease the fatigue strength. Why ?
Last Answer : .Normal carburising/nitriding treatments increase volume due to phase transformation at Surface and introduce residual compressive surface stress and thus increase the fatigue strength. By excessive treatment the ... develop in the regions of high tensile stress and lead to early fatigue failure.
Description : __________ is not a case hardening process. (A) Carburising (B) Nitriding (C) Cyaniding (D) Annealing
Last Answer : (D) Annealing
Description : Pick out the wrong statement. (A) A ferromagnetic material becomes paramagnetic above the 'Curie temperature' (B) Permanent magnets are made of hard materials, whereas electromagnets require soft ... hysterisis loss and coercive forces (D) Tungsten steel and alnico are not hard magnetic materials
Last Answer : Option D
Description : The process of manufacturing steel by heating short lengths of wrought iron bars mixed with charcoal in fire clay crucibles and collecting the molten iron into moulds, is known as (A) Cementation process (B) Crucible process (C) Bessemer process (D) Open hearth process
Last Answer : Answer: Option B
Description : Pick out the wrong statement. (A) Addition of methane to the furnace atmosphere reduces decarburising by hydrogen (B) Nitrogen in presence of steam decor-burises high carbon steel, whereas hydrocarbon ... the metal surface) cause nitride formation with increase in surface hardness (D) None of these
Last Answer : (D) None of these
Description : In tropical regions, (A) The surface gets heated more effectively than the arctic areas (B) After heating, the air becomes lighter and is displaced by cool air from the polar regions (C) The rising tropical air flows towards the polar region in the upper strata (D) All of the above
Last Answer : (D) All of the above
Description : Pick the odd man out of the following. (A) Calorising (B) Pack carburising (C) Nitriding (D) Cyaniding
Last Answer : (A) Calorising
Description : Case hardening is not done by (A) Nitriding (B) Hot dipping (C) Electroplating (D) Both ‘b’ & ‘c’
Description : Pick out the wrong statement. (A) Cold cracking of a weld is due to the presence of hydrogen gas in the weld (B) True stress is given by, σ = σE (1 + εE), where σE and εE ... in the iron blast furnace (D) High residual stress at the surface is beneficial for fatigue properties of a material
Description : In nature, ammonia is synthesisd by nitrifying bacteria using enzymes while in industry it is manufactured from `N_(2)` and `H_(2)` using iron oxide c
Last Answer : In nature, ammonia is synthesisd by nitrifying bacteria using enzymes while in industry it is manufactured from ... use nitrates in place of `N_(2)`.
Description : Pick out the correct statement. (A) Plastics are good conductors of heat and electricity (B) All the polymers are highly crystalline in nature (C) Polymers can be vaporised by heating to ... D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Last Answer : (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
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 : Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of ... nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface
Last Answer : (B) The equivalent diameter of heat transfer for a duct of square crosssection (having each side as 'x') is equal to 4x
Description : Sulphur in metallurgical coal (A) Contributes to its heating value (B) Affects the quality of steel produced as cracks develop on the surface while rolling the steel (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : The wrong statement about `N_(2)O` is :
Last Answer : The wrong statement about `N_(2)O` is : A. It is nitrous oxide B. It is a neutral oxide C. It is not a linear molecule D. It is known as laughing gas
Description : The process of conversion of nitrogen `(N_(2))` to ammonia is termed as
Last Answer : The process of conversion of nitrogen `(N_(2))` to ammonia is termed as
Description : A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The ... = 283 s (B) t = 356 s (C) t = 400 s (D) t = 800 s
Last Answer : (D) t = 800 s
Description : Pick up the correct statement from the following: (A) In basic Bessemer process, the steel heats the converter (B) In open-hearth process, the furnace heats the steel (C) In Siemens process, the impurities of pig iron are oxidised by the oxygen of the ore (D) All the above
Last Answer : Answer: Option D
Description : Pick out the wrong statement. (A) Alloys are harder than their component elements (B) Presence of silicon in steel decreases its electrical resistance (C) Karbate is an acid resistant material of construction ... , a steel alloyed with 10% Ni and 20% Cr can be used upto a temperature of 1100°C
Last Answer : (B) Presence of silicon in steel decreases its electrical resistance
Description : On heating, a white amorphous inorganic compound becomes yellow and on cooling, turns white again. The salt may be
Last Answer : On heating, a white amorphous inorganic compound becomes yellow and on cooling, turns white again. The salt may be A. ... `ZnCO_(3)` D. `K_(2)CO_(3)`
Description : It takes `16 min` to boil some water in an electric kettle. Due to some defect it becomes necessary to remove `10 %` turns of the heating coil of the
Last Answer : It takes `16 min` to boil some water in an electric kettle. Due to some defect it becomes necessary to remove `10 ... min C. `20.9` min D. `13.9` min
Description : Dew point can be best defined as the: a. Absolute temperature at which air, upon heating, will evaporate moisture b. . Percentage of moisture that air can hold at a given temperature ... to condense should the temperature drop further e. . Atmospheric pressure at which air will condense moisture
Last Answer : Answer: D
Description : On heating, Gypsum loses certain percentage of its water content and becomes (1) Chalk (2) Calcium sulphate (3) Plaster of Paris (4) a pearl
Last Answer : (3) Plaster of Paris Explanation: Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
Description : Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat ... in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam
Last Answer : (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature
Description : Delayed allergy reaction (type IV allergic reaction) is: a) An An allergic or immune response that begins within a period lasting from a few minutes to about an hour after exposure to ... of antigen-antibody complexes that cause tissue damage e) An allergic disorder which is transferred genetically.
Last Answer : Ans: B
Description : Immediate allergy reaction (type I allergic reaction) is: a) An allergic or immune response that begins within a period lasting from a few minutes to about an hour after exposure to an ... cause tissue damage e) It occurs during blood transfusion reactions and in hemolytic disease of the newborn.
Last Answer : Ans: A
Description : The cement becomes unsound by the presence of excess (A) Sulphur (B) Magnesia (C) Lime (D) All of these
Description : Railway wagon axles are made by heating rods of iron embedded in charcoal powerder. The process is known as
Last Answer : Railway wagon axles are made by heating rods of iron embedded in charcoal powerder. The process ... hardening B. sheradising C. annelaing D. tempering
Description : Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to ... Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction
Last Answer : (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot
Description : The compound which produce propane on heating with HI in presence of red P is `(a) CH_(3)CH_(2)CH_(2)I " "(b) CH_(3)CH_(2)CHO` `(c) CH_(3)CH_(2)CH_(2)
Last Answer : The compound which produce propane on heating with HI in presence of red P is `(a) CH_(3)CH_(2)CH_(2)I " "(b) ... Only c B. b, c C. b, c, d D. All
Description : An orgainc compound A upon reacting with `NH_(3)` gives `B` On heating `B` give `C.C` in presence `KOH` reacts with `Br_(2)` to yield `CH_(3)CH_(2)NH_
Last Answer : An orgainc compound A upon reacting with `NH_(3)` gives `B` On heating `B` give `C.C` in presence `KOH ... underset(|)(CH)-COOH` D. `CH_(3)CH_(2)COOH`
Description : 4-Hydroxy-4-methylpentanal on heating with excess of methanol in the presence of an acid catalyst followed by dehydration of the products gives
Last Answer : 4-Hydroxy-4-methylpentanal on heating with excess of methanol in the presence of an acid catalyst followed by ... of the products gives A. B. C. D.
Description : The compound formed on heating chlorobenzene with chloral in te presence of concentrated sulphuric acid is
Last Answer : The compound formed on heating chlorobenzene with chloral in te presence of concentrated sulphuric acid is ... B. DDT C. freon D. Hexachloroethane
Description : Upon heating`KCIO_(3)` in presence of catalytic amount of `MnO_(2)`, a gas `W` is formed. Excess amount of `W` reacts with white phosphours to given `
Last Answer : Upon heating`KCIO_(3)` in presence of catalytic amount of `MnO_(2)`, a gas `W` is formed. Excess amount of `W` ... )O_(6)` D. `O_(3) and P_(4)O_(10)`
Description : Upon heating`KClO_(3)` in presence of catalytic amount of `MnO_(2)`, a gas `W` is formed. Excess amount of `W` reacts with white phosphorus to given `
Last Answer : Upon heating`KClO_(3)` in presence of catalytic amount of `MnO_(2)`, a gas `W` is formed. Excess amount of `W` ... PO_(4)` D. `N_(2)O_(5) and HPO_(3)`
Description : A green coloured solid compound ̳X , gets oxidized to reddish brown solid in presence of air. ̳X on heating gives brown coloured solid ̳Y and two pungent smelling gases ̳A and ̳B . ̳A turns acidified potassium ... , SO 3 , decomposition (d) FeSO 4 , Fe 2 O 3 , SO 3 , SO 2 , decomposition
Last Answer : (c) FeSO 4 , Fe 2 O 3, SO 2 , SO 3 , decomposition
Description : Blast furnace coke is made from coal by (A) Low temperature carbonisation (B) High temperature carbonisation (C) Medium temperature carbonisation (D) Heating the coal in an oven in presence of air
Last Answer : (B) High temperature carbonisation
Description : Red phosphorous is changed into white phosphorous by (A) Heating in presence of light (B) Melting under pressure (C) Vaporisation followed by condensation (D) None of these
Last Answer : (C) Vaporisation followed by condensation
Description : Aspirin is produced by heating salicylic acid with (a) acetic anhydride in the presence of phosphoric acid (b) benzoic anhydride in the presence of phosphoric acid (c) methyl alcohol in the presence of sulfuric acid (d) phenol in the presence of sulfuric acid
Last Answer : acetic anhydride in the presence of phosphoric acid
Description : Sulphur removal by heating of pyrite ore in presence of air is called its (A) Reduction (B) Roasting (C) Calcination (D) Smelting
Last Answer : (B) Roasting