Refractory Technology — Part 2 MCQs with Explanations

1730 is the correct answer to “Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.”. This question is standard in competitive examination syllabi for Refractory Technology.

270 is the correct answer to “Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.”. This question is standard in competitive examination syllabi for Refractory Technology.

1730 is the correct answer to “PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.”. This question is standard in competitive examination syllabi for Refractory Technology.

Acid is the correct answer to “Magnesite bricks have poor resistance to attack by __________ slag.”. This question is standard in competitive examination syllabi for Refractory Technology.

Carbon is the correct answer to “__________ bricks should not be used in oxidising atmosphere.”. This question is standard in competitive examination syllabi for Refractory Technology.

High alumina is the correct answer to “__________ bricks are used in the burning zone of a cement rotary kiln.”. This question is standard in competitive examination syllabi for Refractory Technology.

Blast furnace is the correct answer to “High thermal conductivity of a refractory material is not important, when it is to be used in the”. This question is standard in competitive examination syllabi for Refractory Technology.

Thermal conductivity is the correct answer to “Thermal diffusivity of a refractory brick is high, when its __________ is high.”. This question is standard in competitive examination syllabi for Refractory Technology.

Washing action of metal is the correct answer to “Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the”. This question is standard in competitive examination syllabi for Refractory Technology.

80 and 20 is the correct answer to “Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.”. This question is standard in competitive examination syllabi for Refractory Technology.

Lowers is the correct answer to “Presence of MgO in alumino-silicate refractories __________ its refractoriness.”. This question is standard in competitive examination syllabi for Refractory Technology.

Reduced by the addition of acid oxides is the correct answer to “Fusion point of a basic refractory material is”. This question is standard in competitive examination syllabi for Refractory Technology.

None of these is the correct answer to “Which is not a natural insulating material”. This question is standard in competitive examination syllabi for Refractory Technology.

Furnaces subjected to fluctuating temperature is the correct answer to “Zirconia refractories are not used in”. This question is standard in competitive examination syllabi for Refractory Technology.

Beehive coke ovens is the correct answer to “Silica refractories are not used in”. This question is standard in competitive examination syllabi for Refractory Technology.

All of the above is the correct answer to “High alumina refractories are used in the”. This question is standard in competitive examination syllabi for Refractory Technology.

Electric furnace is the correct answer to “Test piece for determination of RUL of a refractory is heated in a/an”. This question is standard in competitive examination syllabi for Refractory Technology.

Chrome or magnesite is the correct answer to “Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.”. This question is standard in competitive examination syllabi for Refractory Technology.

Making it denser is the correct answer to “Spalling resistance of a refractory can not be increased by”. This question is standard in competitive examination syllabi for Refractory Technology.

Fusion point is the correct answer to “An ideal refractory should have high”. This question is standard in competitive examination syllabi for Refractory Technology.

Cristobalite is the correct answer to “Which is the stable form of silica between 1470°C and the melting point 1713°C”. This question is standard in competitive examination syllabi for Refractory Technology.

Either A or B is the correct answer to “Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be”. This question is standard in competitive examination syllabi for Refractory Technology.

20 to 30 is the correct answer to “Porosity of silica bricks varies from __________ percent.”. This question is standard in competitive examination syllabi for Refractory Technology.

90 is the correct answer to “Maximum alumina content in high alumina refractory can be as high as __________ percent.”. This question is standard in competitive examination syllabi for Refractory Technology.

14-20 is the correct answer to “Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.”. This question is standard in competitive examination syllabi for Refractory Technology.

90 is the correct answer to “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.”. This question is standard in competitive examination syllabi for Refractory Technology.

30 is the correct answer to “Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.”. This question is standard in competitive examination syllabi for Refractory Technology.

MgO is the correct answer to “Periclase refractory contains mainly”. This question is standard in competitive examination syllabi for Refractory Technology.

1600 is the correct answer to “In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.”. This question is standard in competitive examination syllabi for Refractory Technology.

Castables is the correct answer to “Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory”. This question is standard in competitive examination syllabi for Refractory Technology.

Low thermal conductivity is the correct answer to “Insulating refractories should have”. This question is standard in competitive examination syllabi for Refractory Technology.

Nuclear reactors, missiles & space crafts is the correct answer to “Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the”. This question is standard in competitive examination syllabi for Refractory Technology.

Fireclay is the correct answer to “Basic bricks are not made of”. This question is standard in competitive examination syllabi for Refractory Technology.

Both A & B is the correct answer to “Alumina-graphite bricks are used for lining the”. This question is standard in competitive examination syllabi for Refractory Technology.

1600-1800 is the correct answer to “Firing temperature of magnesite bricks is about __________ °C.”. This question is standard in competitive examination syllabi for Refractory Technology.

1550 is the correct answer to “Maximum safe working temperature for fireclay bricks is about __________ °C.”. This question is standard in competitive examination syllabi for Refractory Technology.

3Al2O3.2SiO2 is the correct answer to “Chemically, mullite refractories is”. This question is standard in competitive examination syllabi for Refractory Technology.

Are not attacked by slags, as they are not wetted by melts is the correct answer to “Carbon refractories”. This question is standard in competitive examination syllabi for Refractory Technology.

Are used in the hearth of blast furnace is the correct answer to “Carbon refractory blocks”. This question is standard in competitive examination syllabi for Refractory Technology.

Specific gravity is the correct answer to “Conversion of silica mineral to cristobalite is accompanied by reduction in its”. This question is standard in competitive examination syllabi for Refractory Technology.