MCQOPTIONS
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MCQOPTIONS
This section includes 163 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Pyrometric cone equivalent (PCE) of a refractory is the measure of its_________________? |
| A. | Spalling resistance |
| B. | Fusion point |
| C. | Resistance to slag penetration |
| D. | Resistance to carbon monoxide attack |
| Answer» C. Resistance to slag penetration | |
| 52. |
Pure oxide refractories are generally monocrystalline in nature and are self bonded _______________ bricks are generally used as moderator in nuclear reactors? |
| A. | Beryllia |
| B. | Carborundum |
| C. | Corundum |
| D. | Thoria |
| Answer» B. Carborundum | |
| 53. |
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as _____________ percent? |
| A. | 55 |
| B. | 70 |
| C. | 80 |
| D. | 90 |
| Answer» E. | |
| 54. |
Presence of MgO in alumino-silicate refractories _______________ its refractoriness? |
| A. | Increases |
| B. | Lowers |
| C. | Does not affect |
| D. | Either A. or B.; depends on its quantity |
| Answer» C. Does not affect | |
| 55. |
Porosity of silica bricks varies from ______________ percent? |
| A. | 5 to 10 |
| B. | 20 to 30 |
| C. | 45 to 60 |
| D. | 60 to 75 |
| Answer» C. 45 to 60 | |
| 56. |
Porosity of fireclay refractories is _______________ percent? |
| A. | 5-10 |
| B. | 10-25 |
| C. | 25-35 |
| D. | 35-50 |
| Answer» C. 25-35 | |
| 57. |
Porosity is induced in insulating refractories by adding________________? |
| A. | Powdered naphthalene |
| B. | Ammonium chloride/sulphate |
| C. | Calcium phosphate |
| D. | All A., B. and C. |
| Answer» E. | |
| 58. |
Permeability of bricks is a measure of the_________________? |
| A. | Refractoriness |
| B. | Melting point |
| C. | Rate at which a fluid will pass through the pores |
| D. | Expansion during heating |
| Answer» D. Expansion during heating | |
| 59. |
Periclase refractory contains mainly________________? |
| A. | CaO |
| B. | MgO |
| C. | Al2O3 |
| D. | SiO2 |
| Answer» C. Al2O3 | |
| 60. |
Periclase is___________________? |
| A. | Crystalline form of MgO |
| B. | MgCO3 |
| C. | ZrSO4 |
| D. | Amorphous magnesite |
| Answer» B. MgCO3 | |
| 61. |
PCE value (Segar cone) of Superduty refractories is more than 33, which is equivalent to a temperature of ____________ °C? |
| A. | 1520 |
| B. | 1630 |
| C. | 1670 |
| D. | 1730 |
| Answer» E. | |
| 62. |
Panel test determines the _____________ of refractories? |
| A. | Fusion point |
| B. | Spalling resistance |
| C. | Slag penetration resistance |
| D. | Refractoriness under load (RUL) |
| Answer» C. Slag penetration resistance | |
| 63. |
Outer combustion chamber of blast furnace stove is lined with _____________ bricks? |
| A. | Fireclay |
| B. | Silica |
| C. | Chrome magnesite |
| D. | Zirconia |
| Answer» B. Silica | |
| 64. |
____________ of carbon blocks in the hearth of blast furnace helps in avoiding skull formation, when it becomes cold? |
| A. | High thermal conductivity |
| B. | Low porosity |
| C. | Non-wetting characteristics |
| D. | High density |
| Answer» D. High density | |
| 65. |
_____________ nozzles are used in continuous casting of steel? |
| A. | Zircon |
| B. | Thoria |
| C. | Carborundum |
| D. | Beryllia |
| Answer» B. Thoria | |
| 66. |
Natural silica___________________? |
| A. | Mainly contains quartz |
| B. | Is not stable at high temperature |
| C. | Transforms to other allotropic forms i.e. Tridymite and Cristobalite involving very high volume changes |
| D. | All A., B. and C. |
| Answer» E. | |
| 67. |
Mullite is chemically represented by_________________? |
| A. | Al2O3. 2SiO2 |
| B. | 3Al2O3. 2SiO2 |
| C. | Al2O3. SiO2 |
| D. | 2Al2O3. 3SiO2 |
| Answer» C. Al2O3. SiO2 | |
| 68. |
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of ______________ percent respectively? |
| A. | 80 and 20 |
| B. | 20 and 80 |
| C. | 50 and 50 |
| D. | 60 and 40 |
| Answer» B. 20 and 80 | |
| 69. |
Mixing of ground refractory material and water is done in a ______________ mill? |
| A. | Pug |
| B. | Ball |
| C. | Tube |
| D. | Rod |
| Answer» B. Ball | |
| 70. |
Maximum water percentage in refractory mix meant for hand moulding may be as high as _____________ percent? |
| A. | 2-3 |
| B. | 5-7 |
| C. | 7-12 |
| D. | 14-20 |
| Answer» E. | |
| 71. |
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as ______________ percent? |
| A. | 10 |
| B. | 15 |
| C. | 20 |
| D. | 30 |
| Answer» E. | |
| 72. |
Maximum safe working temperature for fireclay bricks is about __________ °C? |
| A. | 1150 |
| B. | 1300 |
| C. | 1450 |
| D. | 1550 |
| Answer» E. | |
| 73. |
Maximum apparent porosity of magnesite bricks is about _____________ percent? |
| A. | 8 |
| B. | 24 |
| C. | 44 |
| D. | 58 |
| Answer» C. 44 | |
| 74. |
Maximum alumina content in high alumina refractory can be as high as _____________ percent? |
| A. | 30 |
| B. | 50 |
| C. | 70 |
| D. | 90 |
| Answer» E. | |
| 75. |
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. | |
| 76. |
Magnesite refractories are used for the construction of those furnaces, which are________________? |
| A. | Not required to resist the corrosive action of basic slag |
| B. | Not subjected to fluctuation in temperature |
| C. | Used for raising & maintaining high temperature |
| D. | Both B. and C. |
| Answer» E. | |
| 77. |
Magnesite chrome bricks are used in the___________________? |
| A. | Roof lining of basic open hearth & other basic furnaces |
| B. | Reheating furnaces |
| C. | Soaking pits |
| D. | All A., B. and C. |
| Answer» E. | |
| 78. |
Magnesite chrome refractories____________________? |
| A. | Have better spalling resistance than chrome magnesite refractories |
| B. | Have very low thermal co-efficient of expansion |
| C. | Are not at all resistant to the corrosive action of iron oxide |
| D. | Have very low (50 kg/cm2) cold crushing strength (C.C.S.), and cannot be used in metalcase form |
| Answer» B. Have very low thermal co-efficient of expansion | |
| 79. |
Magnesite refractories are generally not used in the___________________? |
| A. | Electric furnace walls |
| B. | Steel melting furnace |
| C. | Open hearth furnace |
| D. | Burning zone of cement kilns |
| Answer» C. Open hearth furnace | |
| 80. |
Magnesite bricks have poor resistance to attack by _____________ slag? |
| A. | Lime |
| B. | Basic |
| C. | Acid |
| D. | None of these |
| Answer» D. None of these | |
| 81. |
Magnesite bricks are used in those parts of furnaces, which are __________________? |
| A. | Subjected to temperature fluctuation |
| B. | Required to resist corrosive basic slag |
| C. | Subjected to high load |
| D. | None of these |
| Answer» C. Subjected to high load | |
| 82. |
Machine moulding of dry mixture of refractories requires a pressure of the order of _____________ kg/cm2? |
| A. | 10 |
| B. | 100 |
| C. | 500 |
| D. | 1000 |
| Answer» E. | |
| 83. |
Lower part of hot metal mixer are lined with _____________ bricks? |
| A. | Superduty fireclay |
| B. | High alumina |
| C. | Silica |
| D. | Carborundum |
| Answer» E. | |
| 84. |
Lessing ring is formed by the addition of a partition across the centre of a raschig ring, which results in an area increase of about ______________ percent? |
| A. | 5 |
| B. | 20 |
| C. | 35 |
| D. | 55 |
| Answer» C. 35 | |
| 85. |
___________________ is the measure of the strength of refractory under the combined effect of temperature & load ? |
| A. | Porosity |
| B. | RUL |
| C. | Specific gravity |
| D. | Thermal conductivity |
| Answer» C. Specific gravity | |
| 86. |
_____________ is not a single oxide-refractory? |
| A. | Zirconia |
| B. | Silicon carbide |
| C. | Magnesia |
| D. | None of these |
| Answer» C. Magnesia | |
| 87. |
Insulating refractories should have_______________? |
| A. | High porosity |
| B. | Low thermal conductivity |
| C. | Both A. and B. |
| D. | Neither A. not B. |
| Answer» C. Both A. and B. | |
| 88. |
In panel test for spalling resistance, the average face temperature of panel assembly is maintained at ______________ °C for 24 hours? |
| A. | 700 |
| B. | 1000 |
| C. | 1600 |
| D. | 2000 |
| Answer» D. 2000 | |
| 89. |
In chemical process equipments, the conical bottom heads used, usually has an apex angle of____________________? |
| A. | 20° |
| B. | 40° |
| C. | 60° |
| D. | 80° |
| Answer» D. 80° | |
| 90. |
Hot face insulating linings of high purity alumina fused mullite are used, where_________________? |
| A. | Very high temperatures are involved |
| B. | Highly reducing conditions are involved |
| C. | Presence of iron or silica is harmful |
| D. | All A., B. and C. |
| Answer» E. | |
| 91. |
Hot blast main (carrying air at 1000°C) in blast furnace are lined with ______________ bricks? |
| A. | Silica |
| B. | Fireclay |
| C. | Magnesite |
| D. | Zirconia |
| Answer» C. Magnesite | |
| 92. |
Hollow refractory bricks are made by___________________? |
| A. | Slip casting |
| B. | Hand moulding |
| C. | pressing/machine moulding |
| D. | Extrusion |
| Answer» B. Hand moulding | |
| 93. |
Highest melting (m.p = 3070°C) oxide refractory is__________________? |
| A. | Alumina |
| B. | Thoria |
| C. | Zirconia |
| D. | Magnesia |
| Answer» C. Zirconia | |
| 94. |
High thermal conductivity of a refractory material is not important, when it is to be used in the______________________? |
| A. | Coke oven regenerators |
| B. | Muffle furnace |
| C. | Blast furnace |
| D. | Recuperators |
| Answer» D. Recuperators | |
| 95. |
High refractoriness of refractory bricks means, that it has a________________? |
| A. | High spalling resistance |
| B. | Low spalling resistance |
| C. | High resistance to fusion |
| D. | Low porosity |
| Answer» D. Low porosity | |
| 96. |
High porosity refractory bricks have _______________? |
| A. | Poor resistance to the penetration of molten slag, metal & flue gases |
| B. | Poor heat conductivity & low strength |
| C. | Better thermal spalling resistance |
| D. | All A., B. and C. |
| Answer» E. | |
| 97. |
High density refractory bricks have lower__________________? |
| A. | Spalling resistance |
| B. | Thermal conductivity |
| C. | Fusion point |
| D. | Slag penetration resistance |
| Answer» B. Thermal conductivity | |
| 98. |
High alumina refractory compared to fireclay bricks have____________________? |
| A. | Less load bearing capacity |
| B. | Less resistance to slag attack |
| C. | Low refractoriness |
| D. | High resistance to thermal shock and creep |
| Answer» E. | |
| 99. |
High alumina refractories are used in the ___________________? |
| A. | Dome of blast furnace stoves |
| B. | Electric arc furnace roof |
| C. | Glass melting furnaces |
| D. | All A., B. and C. |
| Answer» E. | |
| 100. |
Grog addition in fireclay during brick manufacture is done to_________________? |
| A. | Reduce its shrinkage on heating |
| B. | Impart greater spalling resistance |
| C. | Enhance the strength of fired refractories |
| D. | All A., B. and C. |
| Answer» E. | |