MCQOPTIONS
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MCQOPTIONS
This section includes 31 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The linear thermal expansion of __________ bricks upto 1000 °C is very low of the order of ≤ 0.5 percent. |
| A. | silica |
| B. | fireclay |
| C. | corundum |
| D. | magnesite |
| Answer» C. corundum | |
| 2. |
\'Super refractories\' are made from pure |
| A. | oxides |
| B. | carbides |
| C. | nitrides |
| D. | borides |
| Answer» B. carbides | |
| 3. |
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. | |
| 4. |
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. | |
| 5. |
Cold crushing strength of fireclay bricks is about __________ kgf/cm 2 . |
| A. | 50-100 |
| B. | 100-150 |
| C. | 200-400 |
| D. | 500-1000 |
| Answer» D. 500-1000 | |
| 6. |
Refractoriness under load (RUL) of fireclay bricks (under a load of 2 kg/cm 2 ) is __________ °C. |
| A. | 500 |
| B. | 1000 |
| C. | >1350 |
| D. | >2000 |
| Answer» D. >2000 | |
| 7. |
Spinel', a refractory mineral is chemically represented as |
| A. | M g Al 2 O 4 |
| B. | M g Al 2 O 3 |
| C. | M g SO 4 |
| D. | M g Al 2 O 3 .2H 2 O |
| Answer» B. M g Al 2 O 3 | |
| 8. |
Which one contains minimum percentage of SiO 2 ? |
| A. | Firebrick |
| B. | Sillimanite |
| C. | Semi-silica |
| D. | Aluminous firebrick |
| Answer» C. Semi-silica | |
| 9. |
Highest melting (m.p = 3070°C) oxide refractory is |
| A. | alumina |
| B. | thoria |
| C. | zirconia |
| D. | magnesia |
| Answer» C. zirconia | |
| 10. |
SiO 2 percentage in firebrick is about |
| A. | 35-40 |
| B. | 55-60 |
| C. | 80-85 |
| D. | >94 |
| Answer» C. 80-85 | |
| 11. |
Which is the stable form of silica upto 1470°C ? |
| A. | Quartz |
| B. | Cristobalite |
| C. | Tridymite |
| D. | None of these |
| Answer» D. None of these | |
| 12. |
Which one contains maximum percentage of Al 2 O 3 ? |
| A. | Firebrick |
| B. | Sillimanite |
| C. | Magnesite |
| D. | Aluminous firebrick |
| Answer» C. Magnesite | |
| 13. |
The highest melting pure oxide (m.p. > 3000°C)is |
| A. | thoria |
| B. | alumina |
| C. | beryllia |
| D. | zirconia |
| Answer» B. alumina | |
| 14. |
Fusion temperature of pure silica (SiO 2 ) is __________ °C. |
| A. | 1350 |
| B. | 1715 |
| C. | 2570 |
| D. | 2800 |
| Answer» C. 2570 | |
| 15. |
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 | |
| 16. |
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 | |
| 17. |
Silliminite (Al 2 O 3 .SiO 2 ) refractory, which is a neutral refractory, is not used in |
| A. | pottery furnace |
| B. | glass melting furnace |
| C. | crucibles |
| D. | gas retorts |
| Answer» E. | |
| 18. |
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm 2 . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm 2 . |
| A. | 450 |
| B. | 250 |
| C. | 150 |
| D. | 65 |
| Answer» E. | |
| 19. |
Machine moulding of dry mixture of refractories requires a pressure of the order of __________ kg/cm 2 . |
| A. | 10 |
| B. | 100 |
| C. | 500 |
| D. | 1000 |
| Answer» E. | |
| 20. |
Maximum safe working temperature for fireclay bricks is about __________ °C. |
| A. | 1150 |
| B. | 1300 |
| C. | 1450 |
| D. | 1550 |
| Answer» E. | |
| 21. |
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. | |
| 22. |
Super refractories' are made from pure |
| A. | carbides |
| B. | oxides |
| C. | borides |
| D. | nitrides |
| Answer» C. borides | |
| 23. |
Firing temperature is minimum (1250-1400 °C) for __________ bricks. |
| A. | fireclay |
| B. | direct bonded basic |
| C. | silica |
| D. | magnesite |
| Answer» B. direct bonded basic | |
| 24. |
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 | |
| 25. |
Refractoriness/fusion points of 'superduty' refractories is __________ °C. |
| A. | 1520-1630 |
| B. | 1630-1670 |
| C. | > 1730 |
| D. | > 2000 |
| Answer» D. > 2000 | |
| 26. |
Which is the stable form of silica below 870°C ? |
| A. | Tridymite |
| B. | Cristobalite |
| C. | Quartz |
| D. | None of these |
| Answer» D. None of these | |
| 27. |
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C. |
| A. | 1520 |
| B. | 1630 |
| C. | 1670 |
| D. | 1730 |
| Answer» E. | |
| 28. |
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 | |
| 29. |
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C. |
| A. | 1380 |
| B. | 1520 |
| C. | 1710 |
| D. | 1915 |
| Answer» D. 1915 | |
| 30. |
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 | |
| 31. |
Firing temperature of magnesite bricks is about __________ °C. |
| A. | 800-1000 |
| B. | 1000-1200 |
| C. | 1600-1800 |
| D. | 2400-2600 |
| Answer» D. 2400-2600 | |