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Free download in PDF Stoichiometry General Knowledge Multiple Choice Questions(MCQs) & Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(1)
Fireclay bricks are not used in the_________________?
[A]
Blast furnace
[B]
Hot blast stove
[C]
Cupola
[D]
Wall of coke oven
Answer: Wall of coke oven
(2)
Which form of silica has the highest specific gravity ?
[A]
Quartz
[B]
Cristobalite
[C]
Tridymite
[D]
All have the same specific gravity
(3)
Thermal conductivity of refractory bricks____________________?
[A]
Increases with decrease in porosity
[B]
Decreases with decreases in porosity
[C]
Is independent of its porosity and is maximum for insulating bricks
[D]
Increases with the amount of air entrapped in pores
Answer: Increases with decrease in porosity
(4)
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: Steel melting furnace
(5)
Which is not an acidic refractory ?
[A]
Carbon black
[B]
Silica
[C]
Fireclay
[D]
High alumina refractory
(6)
Which is a neutral refractory ?
[A]
Graphite
[B]
Magnesite chrome
[C]
Silica
[D]
Magnesia
(7)
Which is an acidic refractory ?
[A]
Magnesite
[B]
Dolomite
[C]
Fireclay
[D]
Chrome magnesite
(8)
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
(9)
Fireclay bricks is not used for lining the_______________?
[A]
Cupola
[B]
Gas producer
[C]
Bottom of hot metal mixer
[D]
Roof of open hearth furnace
Answer: Bottom of hot metal mixer
(10)
Fireclay refractories___________________?
[A]
Are not resistant to the action of basic slags
[B]
Shrink during firing
[C]
Both A and B
[D]
None of These
(11)
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: Beehive coke ovens
(12)
Refractory bricks having lower porosity have _____________________?
[A]
High insulating properties
[B]
Low heat capacity
[C]
Low thermal conductivity
[D]
Greater strength
(13)
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of ________________?
[A]
Fireclay
[B]
Silicon carbide
[C]
Corundum
[D]
Siliceous fireclay
(14)
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
(15)
Quartz is__________________?
[A]
Stable form of silica upto 870°C
[B]
Converted to Tridymite on firing between 870 to 1470°C
[C]
Transformed to Cristobalite on heating above 1470°C
[D]
All A., B. and C.
Answer: All A., B. and C.
(16)
With increase in the porosity, thermal spalling resistance of fireclay brick_______________?
[A]
Increases
[B]
Decreases
[C]
Remain same
[D]
May increase or decrease
(17)
Refractoriness/fusion points of ‘Superduty’ refractories is _____________ °C?
[A]
1520-1630
[B]
1630-1670
[C]
> 1730
[D]
> 2000
(18)
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called_________________?
[A]
Spalling resistance
[B]
Refractoriness
[C]
Refractoriness under load (RUL)
[D]
None of these
Answer: Spalling resistance
(19)
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: Rate at which a fluid will pass through the pores
(20)
Carborundum used for making crucibles for melting non-ferrous metals is chemically________________?
[A]
Silicon carbide
[B]
Silicon nitride
[C]
Crystalline magnesia
[D]
Zirconium sulphate
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