MCQOPTIONS
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MCQOPTIONS
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.
| 151. |
RUL of refractories depends on the$? |
| A. | Chemical composition |
| B. | Physical structure |
| C. | Presence of impurities like iron & alkali |
| D. | All of the above |
| Answer» E. | |
| 152. |
Chromite refractories are used in$? |
| 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 nor B |
| Answer» D. Neither A nor B | |
| 153. |
Which is not a high alumina refractory?$? |
| A. | Mullite |
| B. | Corrundum |
| C. | Bauxite |
| D. | Dolomite |
| Answer» E. | |
| 154. |
Fireclay bricks are not used in the$? |
| 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 | |
| 155. |
Pure oxide refractories are generally monocrystaliine in nature and are self bonded __________ bricks are generally used as moderator in nuclear reactors.$? |
| A. | Beryllia |
| B. | Carborundum |
| C. | Corundum |
| D. | Thoria |
| Answer» B. Carborundum | |
| 156. |
High refractorinness of refractory bricks means, that it has a$? |
| A. | High spalling resistance |
| B. | Low spalling resistance |
| C. | High resistance to fusion |
| D. | Low porosity |
| Answer» D. Low porosity | |
| 157. |
Which of the following does not occur during firing/burning of refractories?$? |
| A. | Removal of water of hydration |
| B. | Vitrification |
| C. | Decrease in crushing strength |
| D. | Development of stable mineral form |
| Answer» D. Development of stable mineral form | |
| 158. |
With increasing alumina content, the fusion point of high alumina refractories$? |
| A. | Increases |
| B. | Decreases |
| C. | Remains constant |
| D. | May increase or decrease ; depends on its alumina content |
| Answer» B. Decreases | |
| 159. |
With increase in the alumina content, the refractoriness of high alumina refractories$? |
| A. | Increases |
| B. | Decreases |
| C. | Remains same |
| D. | May increase or decrease |
| Answer» B. Decreases | |
| 160. |
Fusion point of an acidic refractory material is$? |
| 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. | Not affected by the addition of basic oxides |
| Answer» C. Not affected by the addition of basic oxides | |
| 161. |
Insulating refractories should have$? |
| A. | High porosity |
| B. | Low thermal conductivity |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» C. Both A & B | |
| 162. |
Because of its very high refractoriness of the order of __________ °C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns.$? |
| A. | 1800 |
| B. | 2200 |
| C. | 2400 |
| D. | 2700 |
| Answer» E. | |
| 163. |
A steel member used in the furnace construction to take the thrust of the brickwork is called$? |
| A. | Buckstay |
| B. | Breast wall |
| C. | Armouring |
| D. | Baffle |
| Answer» B. Breast wall | |
| 164. |
With increase in the alumina content, the refractoriness of high alumina refractories? |
| A. | Increases |
| B. | Decreases |
| C. | Remains same |
| D. | May increase or decrease |
| Answer» B. Decreases | |
| 165. |
High refractorinness 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 | |
| 166. |
With increasing alumina content, the fusion point of high alumina refractories? |
| A. | Increases |
| B. | Decreases |
| C. | Remains constant |
| D. | May increase or decrease ; depends on its alumina content |
| Answer» B. Decreases | |
| 167. |
Which of the following does not occur during firing/burning of refractories?? |
| A. | Removal of water of hydration |
| B. | Vitrification |
| C. | Decrease in crushing strength |
| D. | Development of stable mineral form |
| Answer» D. Development of stable mineral form | |
| 168. |
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 nor B |
| Answer» D. Neither A nor B | |
| 169. |
Which is not a high alumina refractory?? |
| A. | Mullite |
| B. | Corrundum |
| C. | Bauxite |
| D. | Dolomite |
| Answer» E. | |
| 170. |
Refractory castables are used for? |
| A. | Producing monolithic linings |
| B. | Patch work |
| C. | Minimising the number of joints in the structure |
| D. | All of the above |
| Answer» E. | |
| 171. |
SiO‚ÇÇ percentage in firebrick is about? |
| A. | 35-40 |
| B. | 55-60 |
| C. | 80-85 |
| D. | >94 |
| Answer» C. 80-85 | |
| 172. |
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 | |
| 173. |
Pure oxide refractories are generally monocrystaliine 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 | |
| 174. |
Natural silica? |
| A. | Mainly contains quartz |
| B. | Is not stable at high temperature |
| C. | Transforms to other allotropic forms i.e tridymite and cristoballite involving very high volume changes |
| D. | All of the above |
| Answer» E. | |
| 175. |
RUL of refractories depends on the? |
| A. | Chemical composition |
| B. | Physical structure |
| C. | Presence of impurities like iron & alkali |
| D. | All of the above |
| Answer» E. | |
| 176. |
A steel member used in the furnace construction to take the thrust of the brickwork is called? |
| A. | Buckstay |
| B. | Breast wall |
| C. | Armouring |
| D. | Baffle |
| Answer» B. Breast wall | |
| 177. |
Because of its very high refractoriness of the order of __________ °C, silicon carbide refractories are used in zinc smelting furnace, muffle furnace and for supporting the wares in tunnel kilns.? |
| A. | 1800 |
| B. | 2200 |
| C. | 2400 |
| D. | 2700 |
| Answer» E. | |
| 178. |
Insulating refractories should have? |
| A. | High porosity |
| B. | Low thermal conductivity |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» C. Both A & B | |
| 179. |
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. | Not affected by the addition of basic oxides |
| Answer» C. Not affected by the addition of basic oxides | |
| 180. |
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 | |
| 181. |
To resist spalling tendency, a refractory should have? |
| A. | Greater diffusivity |
| B. | Low specific heat |
| C. | Low thermal co-efficient of expansion |
| D. | All of the above |
| Answer» E. | |
| 182. |
Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm² ) is __________ °C.? |
| A. | 500 |
| B. | 1000 |
| C. | >1350 |
| D. | >2000 |
| Answer» D. >2000 | |
| 183. |
Thermal spalling mainly occurs during __________ of furnaces.? |
| A. | Cooling down |
| B. | Warming up |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 184. |
Mullite is chemically represented by? |
| A. | Al2O‚ÇÉ . 2SiO‚ÇÇ |
| B. | 3Al2O‚ÇÉ . 2SiO‚ÇÇ |
| C. | Al2O‚ÇÉ . SiO‚ÇÇ |
| D. | 2Al2O‚ÇÉ . 3SiO‚ÇÇ |
| Answer» C. Al2O‚Äö√á√â . SiO‚Äö√á√á | |
| 185. |
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 | |
| 186. |
Cold crushing strength of a refractory does not depend upon its? |
| A. | Shape |
| B. | Composition |
| C. | Firing temperature |
| D. | Texture |
| Answer» B. Composition | |
| 187. |
Maximum safe working temperature for fireclay bricks is about __________ °C.? |
| A. | 1150 |
| B. | 1300 |
| C. | 1450 |
| D. | 1550 |
| Answer» E. | |
| 188. |
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 of the above |
| Answer» E. | |
| 189. |
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 | |
| 190. |
Fusion temperature of pure silica (SiO₂) is __________ °C.? |
| A. | 1350 |
| B. | 1715 |
| C. | 2570 |
| D. | 2800 |
| Answer» C. 2570 | |
| 191. |
Which is an acidic refractory?? |
| A. | Magnesite |
| B. | Dolomite |
| C. | Fireclay |
| D. | Chrome magnesite |
| Answer» D. Chrome magnesite | |
| 192. |
Refractories used in/for __________ should have low thermal conductivity.? |
| A. | Coke ovens |
| B. | Insulation |
| C. | Regenerators |
| D. | Muffle furnaces |
| Answer» C. Regenerators | |
| 193. |
Use of higher percentage of lime for bonding silica bricks, reduces their? |
| A. | Strength |
| B. | Abrasion resistance |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 194. |
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.$ |
| A. | 770 |
| B. | 570 |
| C. | 270 |
| D. | 70 |
| Answer» D. 70 | |
| 195. |
Which is not an acidic refractory? |
| A. | Silica |
| B. | Fireclay |
| C. | High alumina refractory |
| D. | Carbon black |
| Answer» E. | |
| 196. |
Which is the stable form of silica between 1470°C and the melting point 1713°C ?$ |
| A. | Cristobalite |
| B. | Tridymite |
| C. | Quartz |
| D. | None of these |
| Answer» B. Tridymite | |
| 197. |
Silica bricks have low spalling resistance below 600°C, due to its$ |
| A. | Very high thermal conductivity |
| B. | High co-efficient of expansion upto this temperature |
| C. | High thermal diffusivity |
| D. | Low refractoriness |
| Answer» C. High thermal diffusivity | |
| 198. |
An insulating refractory brick should have high porosity and low thermal conductivity. Which of the following is not used for inducing porosity in the insulating refractory bricks during its manufacture? |
| A. | Cork |
| B. | Saw dust |
| C. | Sand |
| D. | Chemically prepared foam |
| Answer» D. Chemically prepared foam | |
| 199. |
Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900°C ) use, except$ |
| A. | Cost |
| B. | Electrical conductivity |
| C. | Thermal conductivity |
| D. | Fusion point |
| Answer» B. Electrical conductivity | |
| 200. |
Which refractory must have controlled atmosphere (temperature and humidity) for its safe storage? |
| A. | Tar bonded dolomite bricks |
| B. | Fireclay bricks |
| C. | Mullite bricks |
| D. | Magnesite bricks |
| Answer» B. Fireclay bricks | |