The purpose of controlling the furnace atmosphere is to prevent surface attack by (A) Oxidation/scaling (B) Decarburising (C) Sulphur penetration (D) Either of the above

The purpose of controlling the furnace atmosphere is to prevent surface
attack by
(A) Oxidation/scaling
(B) Decarburising
(C) Sulphur penetration
(D) Either of the above
by

1 Answer

Answer :

(D) Either of the above
by

Related questions

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 gases carburise the surface of steel at annealing temperatures (C) Active nitrogen (formed by cracking ammonia at the metal surface) cause nitride formation with increase in surface hardness (D) None of these

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

__________ atmosphere is maintained inside an iron blast furnace. (A) Oxidising (B) Reducing (C) Inert (D) Decarburising

Description : __________ atmosphere is maintained inside an iron blast furnace. (A) Oxidising (B) Reducing (C) Inert (D) Decarburising

Last Answer : (B) Reducing

The rate of scaling of furnace stock depends upon the (A) Temperature (B) Time(C) Nature of atmosphere(D) All (A), (B) and (C)

Description : The rate of scaling of furnace stock depends upon the (A) Temperature (B) Time (C) Nature of atmosphere (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Presence of SO2 in furnace gases attacks the ferrous metal by way of (A) Accelerating the rate of scaling (B) Causing metal embrittlement (C) Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature (D) All (A), (B) and (C)

Description : Presence of SO2 in furnace gases attacks the ferrous metal by way of (A) Accelerating the rate of scaling (B) Causing metal embrittlement (C) Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Scaling of furnace stock is reduced by __________ in flue gas. (A) CO (B) H2 (C) High CO/CO2 (D) All (A), (B) & (C)

Description : Scaling of furnace stock is reduced by __________ in flue gas. (A) CO (B) H2 (C) High CO/CO2 (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to (A) Time (B) Square root of time (C) Square of time (D) Cube of time

Description : During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to (A) Time (B) Square root of time (C) Square of time (D) Cube of time

Last Answer : Option B

Magnetic permeability of iron is increased by its (A) Decarburising (B) Alloying with cobalt (C) Purification (D) Alternate heating & cooling

Description : Magnetic permeability of iron is increased by its (A) Decarburising (B) Alloying with cobalt (C) Purification (D) Alternate heating & cooling

Last Answer : Option B

Assertion:- `SF_(6)` cannot be hydrolysed but `SF_(4)` can be. Reason:- Six F atoms in `SF_(6)` prevent the attack of `H_(2)O` on sulphur atom of `SF_

Description : Assertion:- `SF_(6)` cannot be hydrolysed but `SF_(4)` can be. Reason:- Six F atoms in `SF_(6)` prevent the attack of `H_(2)O` on sulphur atom of `SF_

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Stack heat losses can be minimised by (A) Controlling the excess air (B) Oxygen enrichment of combustion air (C) Using low c.v. fuels (D) Maintaining proper draft in the furnace

Description : Stack heat losses can be minimised by (A) Controlling the excess air (B) Oxygen enrichment of combustion air (C) Using low c.v. fuels (D) Maintaining proper draft in the furnace

Last Answer : (A) Controlling the excess air

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Last Answer : (B) Global warming is detrimental for increase in food productivity and may cause flood and cyclone

. Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation

Description : . Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation

Last Answer : (C) Give elasticity & prevent cracking of the film

The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's stray magnetic fields which would interfere with radar C. protect engine room and deck machinery from oxidation in the presence of salt air D. maintain a minimum constant alternator load to prevent overheating

Description : The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's ... the presence of salt air D. maintain a minimum constant alternator load to prevent overheating

Last Answer : Answer: A

Segregation is responsible for (A) Honey-combed concrete (B) Porous layers in concrete (C) Surface scaling in concrete (D) All the above

Description : Segregation is responsible for (A) Honey-combed concrete (B) Porous layers in concrete (C) Surface scaling in concrete (D) All the above

Last Answer : (D) All the above

The increased cohesiveness of concrete, makes it (A) Less liable to segregation (B) More liable to segregation (C) More liable to bleeding (D) More liable for surface scaling in frosty weather

Description : The increased cohesiveness of concrete, makes it (A) Less liable to segregation (B) More liable to segregation (C) More liable to bleeding (D) More liable for surface scaling in frosty weather

Last Answer : Answer: Option A

Segregation in concrete results in (a) Honey combing (b) Porous Layers (c) Surface scaling (d) All the above

Description : Segregation in concrete results in (a) Honey combing (b) Porous Layers (c) Surface scaling (d) All the above

Last Answer : (d) All the above

LSHS is a type of furnace oil, which (A) Is more viscous than high viscosity furnace oil (HVFO) (B) Stands for low sulphur heavy stock (C) Is an ideal fuel for metallurgical furnaces due to its lower sulphur content (< 1%(D) All (A), (B) and (C))

Description : LSHS is a type of furnace oil, which (A) Is more viscous than high viscosity furnace oil (HVFO) (B) Stands for low sulphur heavy stock (C) Is an ideal fuel for metallurgical furnaces due to its lower sulphur content (< 1%) (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Maximum sulphur percentage in low sulphur heavy stock (LSHS) furnace oil is about (A) 0.1 (B) 1 (C) 2.5 (D) 3.5

Description : Maximum sulphur percentage in low sulphur heavy stock (LSHS) furnace oil is about (A) 0.1 (B) 1 (C) 2.5 (D) 3.5

Last Answer : (B) 1

Which of the following petroleum products contain minimum sulphur? (A) Naphtha (B) Kerosene (C) LSHS (D) Furnace oil

Description : Which of the following petroleum products contain minimum sulphur? (A) Naphtha (B) Kerosene (C) LSHS (D) Furnace oil

Last Answer : (A) Naphtha

Which of the following is not an important property of fuel oil/furnace oil? (A) Sulphur content (B) Viscosity (C) Aniline point (D) Flash point

Description : Which of the following is not an important property of fuel oil/furnace oil? (A) Sulphur content (B) Viscosity (C) Aniline point (D) Flash point

Last Answer : (C) Aniline point

Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Which of the following accentuates clinkering trouble on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportions of iron & sulphur (B) Low forced draught and fuel bed temperature (C) Thick fire bed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering trouble on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportions of iron & sulphur (B) Low forced draught and fuel bed temperature (C) Thick fire bed and preheated primary air (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Tar is a better fuel than furnace oil, because of its (A) Higher calorific value (B) Lower sulphur content (C) Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate (D) Both (A) and (B)

Description : Tar is a better fuel than furnace oil, because of its (A) Higher calorific value (B) Lower sulphur content (C) Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate (D) Both (A) and (B)

Last Answer : (D) Both (A) and (B)

Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)

Description : Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

In the manufacture of sulphuric acid from elemental sulphur, the following sequence of major operations is followed: (A) Furnace → converter → absorber (B) Furnace → evaporator → absorber (C) Furnace → converter → evaporator (D) Converter → furnace → absorber

Description : In the manufacture of sulphuric acid from elemental sulphur, the following sequence of major operations is followed: (A) Furnace → converter → absorber (B) Furnace → evaporator → absorber (C) Furnace → converter → evaporator (D) Converter → furnace → absorber

Last Answer : (A) Furnace → converter → absorber

Which of the following contributes maximum as main source of sulphur in the blast furnace charge? (A) Sinter (B) Coke (C) Iron ore (D) Limestone

Description : Which of the following contributes maximum as main source of sulphur in the blast furnace charge? (A) Sinter (B) Coke (C) Iron ore (D) Limestone

Last Answer : Coke

Mass transfer co-efficient is directly proportional to DAB 0.5 , according to __________ theory. (A) Penetration (B) Surface renewal (C) Film (D) None of these

Description : Mass transfer co-efficient is directly proportional to DAB 0.5 , according to __________ theory. (A) Penetration (B) Surface renewal (C) Film (D) None of these

Last Answer : (A) Penetration

Mass transfer co-efficient is directly proportional to DAB according to the __________ theory. (A) Film (B) Penetration (C) Surface-renewal (D) None of these

Description : Mass transfer co-efficient is directly proportional to DAB according to the __________ theory. (A) Film (B) Penetration (C) Surface-renewal (D) None of these

Last Answer : (A) Film

Danckwerts developed the __________ theory. (A) Penetration (B) Surface renewal (C) Film (D) None of these

Description : Danckwerts developed the __________ theory. (A) Penetration (B) Surface renewal (C) Film (D) None of these

Last Answer : (B) Surface renewal

Calculation of mass transfer co-efficient is mostly/normally done using __________ theory. (A) Surface renewal (B) Film (C) Penetration (D) None of these

Description : Calculation of mass transfer co-efficient is mostly/normally done using __________ theory. (A) Surface renewal (B) Film (C) Penetration (D) None of these

Last Answer : (B) Film

For the non catalytic reaction of particles with surrounding fluid, the same needed to achieve the same fractional conversion for particles of different unchanging sizes is proportional to the particle diameter, when the __________ is the controlling resistance. (A) Film diffusion (B) Diffusion through ash layer (C) Chemical reaction (D) Either (A), (B) or (C)

Description : For the non catalytic reaction of particles with surrounding fluid, the same needed to achieve the same fractional conversion for particles of different unchanging sizes is proportional to the particle diameter, when the ... through ash layer (C) Chemical reaction (D) Either (A), (B) or (C)

Last Answer : (C) Chemical reaction

For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, when the __________ is the controlling resistance. (A) Film diffusion (B) Diffusion through ash layer (C) Chemical reaction (D) Either (A), (B) or (C)

Description : For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, ... through ash layer (C) Chemical reaction (D) Either (A), (B) or (C)

Last Answer : (B) Diffusion through ash layer

Neutral atmosphere is maintained in a/an __________ furnace. (A) Cold rolled steel coil annealing (B) Open hearth (C) Soaking pit (D) Walking beam reheating

Description : Neutral atmosphere is maintained in a/an __________ furnace. (A) Cold rolled steel coil annealing (B) Open hearth (C) Soaking pit (D) Walking beam reheating

Last Answer : (A) Cold rolled steel coil annealing

Reducing atmosphere is maintained in a (A) Calcination kiln (B) Blast furnace (C) Soaking pit (D) L.D. converter

Description : Reducing atmosphere is maintained in a (A) Calcination kiln (B) Blast furnace (C) Soaking pit (D) L.D. converter

Last Answer : (B) Blast furnace

In a muffle furnace, the muffle (A) Retards the heat transfer (B) Assists in temperature equalisation in the charge (C) Permits the use of controlled atmosphere for the protection of stock (D) All (A), (B) and (C)

Description : In a muffle furnace, the muffle (A) Retards the heat transfer (B) Assists in temperature equalisation in the charge (C) Permits the use of controlled atmosphere for the protection of stock (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

In order to maintain an oxidising atmosphere in a furnace, it should have (A) More of excess air (B) Less of excess air (C) More of CO in flue gas (D) More of CO2 in flue gas

Description : In order to maintain an oxidising atmosphere in a furnace, it should have (A) More of excess air (B) Less of excess air (C) More of CO in flue gas (D) More of CO2 in flue gas

Last Answer : (A) More of excess air

Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a (A) Furnace employing neutral atmosphere (B) Carbon resistance furnace (C) Reducing atmosphere (D) Furnace employing negative pressure

Description : Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a (A) Furnace employing neutral atmosphere (B) Carbon resistance furnace (C) Reducing atmosphere (D) Furnace employing negative pressure

Last Answer : (B) Carbon resistance furnace

Pick out the wrong statement. (A) Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal (B) Low grade coal can be used, but generally high volatile matter coals are more suitable for making pulverised fuel (C) Regulation of furnace temperature and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing (D) None of these

Description : Pick out the wrong statement. (A) Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal (B) Low grade coal can be used, but generally high volatile ... and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing (D) None of these

Last Answer : (D) None of these

Combustion of pulverised fuel (A) Requires larger combustion chamber than rich gaseous fuel (B) In a metallurgical furnace does not contaminate the product in the furnace by ash from fuel (C) Suppresses the discharge of fine dust and grit into atmosphere (D) All (A), (B) and (C)

Description : Combustion of pulverised fuel (A) Requires larger combustion chamber than rich gaseous fuel (B) In a metallurgical furnace does not contaminate the product in the furnace by ash from fuel (C) Suppresses the discharge of fine dust and grit into atmosphere (D) All (A), (B) and (C)

Last Answer : (A) Requires larger combustion chamber than rich gaseous fuel

Gum formation in stored gasoline is mainly due to the (A) Alkylation of unsaturated (B) Presence of sulphur (C) Oxidation & polymerisation of unsaturated (D) Higher aromatic content

Description : Gum formation in stored gasoline is mainly due to the (A) Alkylation of unsaturated (B) Presence of sulphur (C) Oxidation & polymerisation of unsaturated (D) Higher aromatic content

Last Answer : (B) Presence of sulphur

Dearomatization of kerosene (by liquid sulphur dioxide extraction) is done to (A) Increase its smoke point (B) Improve its oxidation stability (C) Decrease the breathing loss (D) None of these

Description : Dearomatization of kerosene (by liquid sulphur dioxide extraction) is done to (A) Increase its smoke point (B) Improve its oxidation stability (C) Decrease the breathing loss (D) None of these

Last Answer : (B) Improve its oxidation stability

An example of autothermal reactor operation is (A) Sulphur dioxide oxidation (B) Ethylene oxidation (C) Benzene oxidation (D) Ammonia synthesis

Description : An example of autothermal reactor operation is (A) Sulphur dioxide oxidation (B) Ethylene oxidation (C) Benzene oxidation (D) Ammonia synthesis

Last Answer : (B) Ethylene oxidation

With increase in temperature, the equilibrium constant at constant pressure (Kp) for oxidation of sulphur dioxide (A) Increases(B) Increases linearly(C) Decreases(D) Decreases linearly

Description : With increase in temperature, the equilibrium constant at constant pressure (Kp) for oxidation of sulphur dioxide (A) Increases (B) Increases linearly (C) Decreases (D) Decreases linearly

Last Answer : (C) Decreases

The catalyst used in the production of elemental sulphur from H2S (by oxidation-reduction) is (A) Alumina (B) Silica gel(C) Platinum(D) Nickel

Description : The catalyst used in the production of elemental sulphur from H2S (by oxidation-reduction) is (A) Alumina (B) Silica gel (C) Platinum (D) Nickel

Last Answer : (A) Alumina

Oils are partially hydrogenated (not fully) to manufacture Vanaspati, because fully saturated solidified oils (A) Cause cholesterol build up and blood clotting (B) Are prone to rancid oxidation (C) Always contain some amount of nickel (as their complete removal is very difficult) (D) Have affinity to retain harmful sulphur compounds

Description : Oils are partially hydrogenated (not fully) to manufacture Vanaspati, because fully saturated solidified oils (A) Cause cholesterol build up and blood clotting (B) Are prone to rancid oxidation (C ... (as their complete removal is very difficult) (D) Have affinity to retain harmful sulphur compounds

Last Answer : (A) Cause cholesterol build up and blood clotting

The main purpose of galvanising iron sheets is to (A) Harden the surface (B) Increase its glossiness and lustre (C) Prevent the action of water (D) Prevent the action of oxygen

Description : The main purpose of galvanising iron sheets is to (A) Harden the surface (B) Increase its glossiness and lustre (C) Prevent the action of water (D) Prevent the action of oxygen

Last Answer : (C) Prevent the action of water

Pot furnace which is either regenerative or recuperative, is used in the manufacture of (A) Glass (B) Stainless steel (C) Potteries (D) Refractory bricks

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

Maximum heat transfer in high temperature furnaces is by (A) Conduction (B) Convection (C) Radiation (D) Either (A), (B) or (C); depends on the type of furnace

Description : Maximum heat transfer in high temperature furnaces is by (A) Conduction (B) Convection (C) Radiation (D) Either (A), (B) or (C); depends on the type of furnace

Last Answer : (C) Radiation

Find false statement about effect of sulphur in fuel? (A) It has heating value (B) It helps in electrostatic precipitation of ash in flue gases (C) It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low (D) It erodes furnace walls

Description : Find false statement about effect of sulphur in fuel? (A) It has heating value (B) It helps in electrostatic precipitation of ash in flue gases (C) It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low (D) It erodes furnace walls

Last Answer : (D) It erodes furnace walls