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This section includes 209 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
With increase in the density of silica refractories, its%! |
A. | Resistance to slag attack increases |
B. | Spalling resistance reduces |
C. | Both A & B |
D. | Neither A nor B |
Answer» D. Neither A nor B | |
2. |
Which of the following impurities reduces the refractoriness of magnesite bricks?%! |
A. | Al2O‚ÇÉ |
B. | CaO |
C. | SiO‚ÇÇ |
D. | All of the above |
Answer» E. | |
3. |
Resistance to slag attack of a refractory%! |
A. | Depends on the nature of slag & refractory |
B. | Decreases at higher temperature |
C. | Decreases, if defective joints & cracks exist in the refractory |
D. | All of the above |
Answer» E. | |
4. |
Which form of silica has the highest specific gravity?%! |
A. | Quartz |
B. | Cristobalite |
C. | Tridymite |
D. | All of the above |
Answer» B. Cristobalite | |
5. |
Graphite or carbon refractories%! |
A. | Exihibit wetting characteristics |
B. | Should be used in neutral or reducing atmosphere |
C. | Exhibit high shrinkage on thermal treatment |
D. | Are not resistant to corrosion by slag |
Answer» C. Exhibit high shrinkage on thermal treatment | |
6. |
Dilatometer is used for the determination of __________ of refractories.%! |
A. | Modulus of rupture |
B. | Permanent linear change |
C. | Resistance to CO attack |
D. | RUL |
Answer» C. Resistance to CO attack | |
7. |
With decrease in porosity, the __________ of the refractories decreases.%! |
A. | Strength |
B. | Thermal conductivity |
C. | Spalling resistance |
D. | None of these |
Answer» D. None of these | |
8. |
Refractory bricks with lower permeability is produced by using%! |
A. | Higher firing temperature |
B. | Higher moulding pressure |
C. | Finer grog size |
D. | All of the above |
Answer» E. | |
9. |
__________ nozzles are used in continuous casting of steel,%! |
A. | Zircon |
B. | Thoria |
C. | Carborundum |
D. | Beryllia |
Answer» B. Thoria | |
10. |
Bottom of basic open hearth furnace are constructed of%! |
A. | Dead burnt magnesite ramming mass |
B. | Porous fireclay bricks |
C. | Semi-silica bricks |
D. | Silicon carbide bricks |
Answer» B. Porous fireclay bricks | |
11. |
Sillimanite is a __________ refractory.%! |
A. | Basic |
B. | Neutral |
C. | High alumina |
D. | Insulating |
Answer» D. Insulating | |
12. |
Silica refractories%! |
A. | Crack when subjected to sudden change of temperature |
B. | Can not be used in the dome of hot blast stoves |
C. | Have lower thermal conductivity than fireclay bricks |
D. | All of the above |
Answer» B. Can not be used in the dome of hot blast stoves | |
13. |
Silica bricks are never used for lining the%! |
A. | Beehive coke ovens |
B. | By-product coke ovens |
C. | Dome of blast furnace stoves |
D. | Roof of open hearth furnace |
Answer» B. By-product coke ovens | |
14. |
Alumina-graphite bricks are used for lining the%! |
A. | Slide gate in teeming laddies |
B. | Continuous casting systems |
C. | Both A & B |
D. | Neither A nor B |
Answer» D. Neither A nor B | |
15. |
'Spinel', a refractory mineral is chemically represented as%! |
A. | MgAl2O‚ÇÑ |
B. | MgAl2O‚ÇÉ |
C. | MgSO‚ÇÑ |
D. | MgAl2O‚ÇÉ.2H‚ÇÇO |
Answer» B. MgAl2O‚Äö√á√â | |
16. |
Which is a basic refractory?%! |
A. | Fireclay |
B. | Silica |
C. | Chrome magnesite |
D. | None of these |
Answer» D. None of these | |
17. |
*$_Silica refractories? |
A. | Crack when subjected to sudden change of temperature |
B. | Can not be used in the dome of hot blast stoves |
C. | Have lower thermal conductivity than fireclay bricks |
D. | All of the above |
Answer» B. Can not be used in the dome of hot blast stoves | |
18. |
*$_Sillimanite is a __________ refractory.? |
A. | Basic |
B. | Neutral |
C. | High alumina |
D. | Insulating |
Answer» D. Insulating | |
19. |
*$_Bottom of basic open hearth furnace are constructed of? |
A. | Dead burnt magnesite ramming mass |
B. | Porous fireclay bricks |
C. | Semi-silica bricks |
D. | Silicon carbide bricks |
Answer» B. Porous fireclay bricks | |
20. |
*$_Graphite or carbon refractories? |
A. | Exihibit wetting characteristics |
B. | Should be used in neutral or reducing atmosphere |
C. | Exhibit high shrinkage on thermal treatment |
D. | Are not resistant to corrosion by slag |
Answer» C. Exhibit high shrinkage on thermal treatment | |
21. |
*$_Refractory bricks with lower permeability is produced by using? |
A. | Higher firing temperature |
B. | Higher moulding pressure |
C. | Finer grog size |
D. | All of the above |
Answer» E. | |
22. |
*$___________ nozzles are used in continuous casting of steel,? |
A. | Zircon |
B. | Thoria |
C. | Carborundum |
D. | Beryllia |
Answer» B. Thoria | |
23. |
*$_Dilatometer is used for the determination of __________ of refractories.? |
A. | Modulus of rupture |
B. | Permanent linear change |
C. | Resistance to CO attack |
D. | RUL |
Answer» C. Resistance to CO attack | |
24. |
*$_With decrease in porosity, the __________ of the refractories decreases.? |
A. | Strength |
B. | Thermal conductivity |
C. | Spalling resistance |
D. | None of these |
Answer» D. None of these | |
25. |
*$_Which is a basic refractory?? |
A. | Fireclay |
B. | Silica |
C. | Chrome magnesite |
D. | None of these |
Answer» D. None of these | |
26. |
*$_'Spinel', a refractory mineral is chemically represented as? |
A. | MgAl2O‚ÇÑ |
B. | MgAl2O‚ÇÉ |
C. | MgSO‚ÇÑ |
D. | MgAl2O‚ÇÉ.2H‚ÇÇO |
Answer» B. MgAl2O‚Äö√á√â | |
27. |
*$_Alumina-graphite bricks are used for lining the? |
A. | Slide gate in teeming laddies |
B. | Continuous casting systems |
C. | Both A & B |
D. | Neither A nor B |
Answer» D. Neither A nor B | |
28. |
*$_Silica bricks are never used for lining the? |
A. | Beehive coke ovens |
B. | By-product coke ovens |
C. | Dome of blast furnace stoves |
D. | Roof of open hearth furnace |
Answer» B. By-product coke ovens | |
29. |
*$_Zirconia refractory? |
A. | Does not react with basic slags |
B. | Is produced from baddeleyite |
C. | Can not be used as an insulator |
D. | Has poor electrical conductivity at high temperature |
Answer» C. Can not be used as an insulator | |
30. |
*$_Carbon refractories are exclusively used in the? |
A. | Hearth of blast furnace |
B. | Walls of coke oven |
C. | Regenerators of coke oven |
D. | Side wall of soaking pits |
Answer» B. Walls of coke oven | |
31. |
*$_Fireclay refractories have? |
A. | Low co-efficient of thermal expansion |
B. | Poor thermal spalling resistance |
C. | Tendency to expand unduly high during firing |
D. | Very high cost |
Answer» B. Poor thermal spalling resistance | |
32. |
*$_Which is the stable form of silica upto 1470°C ?? |
A. | Quartz |
B. | Cristobalite |
C. | Tridymite |
D. | None of these |
Answer» D. None of these | |
33. |
*$_Silicon carbide refractories are used in the? |
A. | Muffle furnace |
B. | Zinc smelting furnace |
C. | Ceramic recuperators |
D. | All of the above |
Answer» E. | |
34. |
*$_Magnesite refractories have low resistance to? |
A. | Attack by basic slag |
B. | Abrasion |
C. | Disintegration on sudden change of temperature |
D. | Both B and C |
Answer» E. | |
35. |
*$_Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?? |
A. | High refractoriness |
B. | High resistance to spalling |
C. | High strength and density |
D. | All of the above |
Answer» B. High resistance to spalling | |
36. |
*$_Carbon refractory blocks? |
A. | Are wetted by molten iron |
B. | Are used in the hearth of blast furnace |
C. | Are acidic in nature |
D. | All of the above |
Answer» C. Are acidic in nature | |
37. |
*$_Chromite refractories are? |
A. | Acidic refractory |
B. | Neutral refractory |
C. | Basic refractory |
D. | Fired at a temperature of 600°C only |
Answer» C. Basic refractory | |
38. |
*/*_The highest melting pure oxide (m.p. > 3000°C) is? |
A. | Thoria |
B. | Alumina |
C. | Beryllia |
D. | Zirconia |
Answer» B. Alumina | |
39. |
*/*_Which of the following consumes the maximum tonnage of refractories annually in an integrated steel plant?? |
A. | Soaking pits |
B. | Ceheating furnace |
C. | L.D. converter |
D. | Rotary lime kiln |
Answer» D. Rotary lime kiln | |
40. |
*/*_Chrome magnesite brick is not used for lining the? |
A. | Hearth of soaking pits |
B. | Bottom hearth of reheating furnace |
C. | Coke oven regenerator |
D. | Burning zone of limestone rotary kilns |
Answer» D. Burning zone of limestone rotary kilns | |
41. |
*/*_Si percentage in silica refractories used in the walls of coke oven is about? |
A. | 45 |
B. | 60 |
C. | 80 |
D. | 95 |
Answer» E. | |
42. |
*/*_Chrome magnesite bricks are used in the? |
A. | Side walls of soaking pits and arc furnaces |
B. | Copper melting furnaces & converters |
C. | Burner block of glass tanks |
D. | All of the above |
Answer» E. | |
43. |
*/*_Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.? |
A. | 1380 |
B. | 1520 |
C. | 1710 |
D. | 1915 |
Answer» D. 1915 | |
44. |
*/*_Addition of zircon to silica refractory brick improves its? |
A. | Crushing strength |
B. | Resistance to slag attack |
C. | Neither A nor B |
D. | Neither A nor B |
Answer» C. Neither A nor B | |
45. |
*/*_Magnesite bricks have poor resistance to attack by __________ slag.? |
A. | Lime |
B. | Basic |
C. | Acid |
D. | None of these |
Answer» D. None of these | |
46. |
*/*_Hot metal runner in blast furnace are lined with __________ bricks.? |
A. | Silica |
B. | Carborundum |
C. | Fireclay |
D. | Magnesite |
Answer» D. Magnesite | |
47. |
*/*_Roof of a basic electric furnace is made of __________ bricks.? |
A. | Superduty fireclay |
B. | Silica |
C. | Chromite |
D. | None of these |
Answer» C. Chromite | |
48. |
*/*___________ is not a single oxiderefractory.? |
A. | Zirconia |
B. | Silicon carbide |
C. | Magnesia |
D. | None of these |
Answer» C. Magnesia | |
49. |
*/*_Lower part of hot metal mixer are lined with __________ bricks.? |
A. | Superduty fireclay |
B. | High alumina |
C. | Silica |
D. | Carborundum |
Answer» E. | |
50. |
*/*_An indication of degree of firing in silica brick is its? |
A. | Specific gravity |
B. | Fusion point |
C. | RUL |
D. | None of these |
Answer» B. Fusion point | |