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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.
101. |
Grog__________________? |
A. | Contains both alumina and silica |
B. | Is crushed firebrick |
C. | Is a non-plastic material |
D. | All A., B. and C. |
Answer» E. | |
102. |
Graphite or carbon refractories______________________? |
A. | Exhibit 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 | |
103. |
Ganister is a source of the ________________? |
A. | Silica |
B. | Periclase |
C. | Lime |
D. | None of these |
Answer» B. Periclase | |
104. |
Fusion temperature of pure silica (SiO2) is _______________ °C? |
A. | 1350 |
B. | 1715 |
C. | 2570 |
D. | 2800 |
Answer» C. 2570 | |
105. |
Fusion point of an acidic refractory material is________________? |
A. | Increased by the addition of basic oxides |
B. | Reduced by the addition of basic oxides |
C. | Not affected by the addition of basic oxides |
D. | Always more than 2500°C |
Answer» C. Not affected by the addition of basic oxides | |
106. |
Fusion point of a basic refractory material is__________________? |
A. | Reduced by the addition of acid oxides |
B. | Increased by the addition of acid oxides |
C. | Not affected by the addition of acid oxides |
D. | Always less than 1000°C |
Answer» B. Increased by the addition of acid oxides | |
107. |
Furnace atmosphere for softening temperature determination of refractories (in which Seger Cones are placed) should be __________________? |
A. | Oxidising |
B. | Neutral |
C. | Either A. or B. |
D. | Neither A. nor B. |
Answer» D. Neither A. nor B. | |
108. |
Firing temperature of magnesite bricks is about _____________ °C? |
A. | 800-1000 |
B. | 1000-1200 |
C. | 1600-1800 |
D. | 2400-2600 |
Answer» D. 2400-2600 | |
109. |
Firing temperature is minimum (1250-1400 °C) for _______________ bricks? |
A. | Fireclay |
B. | Direct bonded basic |
C. | Silica |
D. | Magnesite |
Answer» B. Direct bonded basic | |
110. |
Firing of refractory brick is done to __________________? |
A. | Dehydrate the dried refractory |
B. | Develop stable mineral forms in them |
C. | Form ceramic bonds necessary for development of high crushing strength in the finished product |
D. | All A., B. and C. |
Answer» E. | |
111. |
Fireclay refractories____________________? |
A. | Are not resistant to the action of basic slags |
B. | Combine with salts (e.g. chlorides sulphates etc.) & bases (e.g. lime, magnesia etc.) forming fusible aluminates silicates etc |
C. | Shrink during firing |
D. | All A., B. and C. |
Answer» E. | |
112. |
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 | |
113. |
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» D. Roof of open hearth furnace | |
114. |
Fireclay bricks are used in the___________________? |
A. | Furnaces allowed to cool frequently |
B. | Flues |
C. | Chimney linings |
D. | All A., B. and C. |
Answer» E. | |
115. |
Fireclay bricks are used in the__________________? |
A. | Coke ovens regenerator |
B. | Outer lining of L.D. converter |
C. | Hearth bottom of blast furnace |
D. | Coke oven walls |
Answer» C. Hearth bottom of blast furnace | |
116. |
Fireclay bricks are not used in the_____________________? |
A. | Blast furnace |
B. | Hot blast stove |
C. | Cupola |
D. | Wall of coke oven |
Answer» E. | |
117. |
Fireclay bricks are never used in the______________? |
A. | Beehive oven |
B. | Coke oven walls |
C. | Zinc roaster |
D. | Lead blast furnace |
Answer» C. Zinc roaster | |
118. |
Fireclay bricks are not used in the _________________? |
A. | Beehive coke oven |
B. | By-product coke oven walls |
C. | Combustion chamber of B.F. stoves |
D. | Coke oven regenerators |
Answer» C. Combustion chamber of B.F. stoves | |
119. |
Ferromagnetic ceramic material is not used in the__________________? |
A. | Thermal insulation |
B. | Transformers |
C. | Magnetic switches |
D. | Television sets |
Answer» B. Transformers | |
120. |
Faster rate of drying of moulded refractories results in high _____________ of refractories? |
A. | Green strength |
B. | Voids |
C. | Shrinkage |
D. | Both B. and C. |
Answer» E. | |
121. |
Except _____________, all other refractories are bad conductors of electricity (i.e, have low electrical conductivity)? |
A. | Fireclay |
B. | Carborundum |
C. | Graphite |
D. | Chromite |
Answer» D. Chromite | |
122. |
Electrical resistor bars are made of _______________? |
A. | Silicon carbide |
B. | Alumina |
C. | Zirconia |
D. | Graphite |
Answer» B. Alumina | |
123. |
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory_________________? |
A. | Mortars |
B. | Cements |
C. | Castables |
D. | None of these |
Answer» D. None of these | |
124. |
Dolomite bricks have good resistance to attack by_____________________? |
A. | Molten steel |
B. | Iron oxide |
C. | Lime slag |
D. | None of these |
Answer» B. Iron oxide | |
125. |
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 | |
126. |
Crushing strength of a refractory____________________? |
A. | Increases with rise in service temperature |
B. | Decreases with rise in service temperature |
C. | Is unaffected with change in service temperature |
D. | Decreases with increase in porosity |
Answer» C. Is unaffected with change in service temperature | |
127. |
Conversion of silica mineral to Cristobalite is accompanied by reduction in its ____________________? |
A. | Volume |
B. | Specific gravity |
C. | Both A. & B. |
D. | Neither A. nor B. |
Answer» C. Both A. & B. | |
128. |
Colour of fireclay bricks is_________________? |
A. | Light buff to reddish buff |
B. | Yellow |
C. | Black |
D. | None of these |
Answer» B. Yellow | |
129. |
Cold crushing strength of refractories depends upon its_________________? |
A. | Composition |
B. | Texture |
C. | Firing temperature |
D. | All A., B. and C. |
Answer» E. | |
130. |
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm2. On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as ______________ kg/cm2? |
A. | 450 |
B. | 250 |
C. | 150 |
D. | 65 |
Answer» E. | |
131. |
Cold crushing strength of fireclay bricks is about ______________ kgf/cm2? |
A. | 50-100 |
B. | 100-150 |
C. | 200-400 |
D. | 500-1000 |
Answer» D. 500-1000 | |
132. |
Cold crushing strength of a refractory does not depend upon its ____________________? |
A. | Shape |
B. | Composition |
C. | Firing temperature |
D. | Texture |
Answer» B. Composition | |
133. |
Chromite refractories_____________________? |
A. | Are bonded with lime and clay |
B. | (Free from silica) have better thermal fatigue resistance than silica and magnesite refractories. |
C. | Are resistant to basic slag |
D. | All A., B. and C. |
Answer» E. | |
134. |
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 | |
135. |
Chromite refractories are used in_______________? |
A. | Bottom of soaking pits |
B. | Between acid & basic linings in basic open hearth furnaces to prevent their chemical action with each other |
C. | Both A. & B. |
D. | Neither A. and B. |
Answer» D. Neither A. and B. | |
136. |
Chrome magnesite is not used in the ____________________? |
A. | Inner lining of L.D. converter |
B. | Aluminium melting furnaces |
C. | Wear out lining of steel melting furnaces |
D. | All A., and B. and C. |
Answer» D. All A., and B. and C. | |
137. |
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 A., B. and C. |
Answer» E. | |
138. |
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 | |
139. |
Chrome magnesite bricks are_________________? |
A. | Acidic in nature |
B. | Neutral in nature |
C. | Having higher RUL than silica bricks |
D. | Made by mixing 30% Chromite and 70% Periclase |
Answer» D. Made by mixing 30% Chromite and 70% Periclase | |
140. |
Chemically, mullite refractories is____________________? |
A. | 3Al2O3.2SiO2 |
B. | Al2O3 |
C. | ZrSO4 |
D. | ThO2 |
Answer» B. Al2O3 | |
141. |
Cermets are____________________? |
A. | Composite material containing both ceramic & metallic constituents |
B. | Having high strength & resistance to high temperature |
C. | Used in space vehicles, missiles & nuclear energy plants |
D. | All A., B. and C. |
Answer» E. | |
142. |
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the_______________? |
A. | Hearth of the blast furnace |
B. | Nuclear reactors, missiles & space crafts |
C. | Insulation of high temperature furnaces |
D. | Roof of electric furnaces |
Answer» C. Insulation of high temperature furnaces | |
143. |
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 |
Answer» C. Corundum | |
144. |
Carborundum used for making crucibles for melting non-ferrous metals is chemically________________? |
A. | Silicon carbide |
B. | Silicon nitride |
C. | Crystalline magnesia |
D. | Zirconium sulphate |
Answer» B. Silicon nitride | |
145. |
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 A., B. and C. |
Answer» C. Are acidic in nature | |
146. |
Carbon refractories_____________________? |
A. | Do not burn/oxidise, when exposed to air on heating |
B. | Are not attacked by slags, as they are not wetted by melts |
C. | Do not resist temperature fluctuations |
D. | Have extremely low thermal & electrical conductivities |
Answer» C. Do not resist temperature fluctuations | |
147. |
Carbon refractories have very high __________________? |
A. | Wetting characteristics |
B. | Refractoriness |
C. | Thermal conductivity |
D. | Both B. and C. |
Answer» E. | |
148. |
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 | |
149. |
Carbon bricks are not used in the lining of the_________________? |
A. | Combustion chamber of blast furnace stoves |
B. | Electric furnaces |
C. | Highly chemical resistant equipments |
D. | Blast furnace hearth |
Answer» B. Electric furnaces | |
150. |
______________ bricks should not be used in oxidising atmosphere? |
A. | Tar dolomite |
B. | Carbon |
C. | Silica |
D. | Fireclay |
Answer» C. Silica | |