MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Regenerators are normally provided in the$? |
| A. | Glass melting furnace |
| B. | Open hearth furnace |
| C. | By product coke ovens |
| D. | All of the above |
| Answer» E. | |
| 2. |
Regenerators are used for waste heat recovery in$? |
| A. | By-product coke ovens |
| B. | Beehive coke oven |
| C. | Blast furnace stoves |
| D. | Soaking pits |
| Answer» B. Beehive coke oven | |
| 3. |
Heat transfer rate to the charge/stock in a furnace does not depend upon the$? |
| A. | Type of fuels viz solid, liquid or gaseous |
| B. | Flue gas temperature |
| C. | Emissivity of refractory walls |
| D. | Initial temperature of the charged stock |
| Answer» B. Flue gas temperature | |
| 4. |
Which of the following is a directly fired intermittant furnace?$? |
| A. | Walking beam reheating furnace |
| B. | Reverberatory furnace |
| C. | Tower furnace |
| D. | Tunnel kiln |
| Answer» C. Tower furnace | |
| 5. |
Thermal efficiency of blast furnace stoves used for heating blast (air) may be about __________ percent.$? |
| A. | 20 |
| B. | 40 |
| C. | 60 |
| D. | 80 |
| Answer» E. | |
| 6. |
The resistance furnace produces heat by the$? |
| A. | Electric arc struck between electrodes and the charge |
| B. | Flow of current through a heating element |
| C. | Combination of induced current and skin effect |
| D. | None of these |
| Answer» C. Combination of induced current and skin effect | |
| 7. |
Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of$? |
| A. | Graphite powder |
| B. | Thoria |
| C. | Zircon powder |
| D. | Beryllium |
| Answer» D. Beryllium | |
| 8. |
Which of the following is the most important deterrants to an extended use of pulverised coal in boiler firing?$? |
| A. | Ash disposal problem |
| B. | Excessive fly ash discharge from the stack |
| C. | Higher power consumption in its transportation |
| D. | Erosion of induced draft fan blades |
| Answer» B. Excessive fly ash discharge from the stack | |
| 9. |
Neutral atmosphere is maintained in a/an __________ furnace.$? |
| A. | Cold rolled steel coil annealing |
| B. | Open hearth |
| C. | Soaking pit |
| D. | Walking beam reheating |
| Answer» B. Open hearth | |
| 10. |
In salt bath furnace, heat is transferred to the charge mainly by$? |
| A. | Conduction |
| B. | Convection |
| C. | Radiation |
| D. | None of these |
| Answer» B. Convection | |
| 11. |
The resistance furnace produces heat by the? |
| A. | Electric arc struck between electrodes and the charge |
| B. | Flow of current through a heating element |
| C. | Combination of induced current and skin effect |
| D. | None of these |
| Answer» C. Combination of induced current and skin effect | |
| 12. |
Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of? |
| A. | Graphite powder |
| B. | Thoria |
| C. | Zircon powder |
| D. | Beryllium |
| Answer» D. Beryllium | |
| 13. |
Neutral atmosphere is maintained in a/an __________ furnace.? |
| A. | Cold rolled steel coil annealing |
| B. | Open hearth |
| C. | Soaking pit |
| D. | Walking beam reheating |
| Answer» B. Open hearth | |
| 14. |
Which of the following is the most important deterrants to an extended use of pulverised coal in boiler firing?? |
| A. | Ash disposal problem |
| B. | Excessive fly ash discharge from the stack |
| C. | Higher power consumption in its transportation |
| D. | Erosion of induced draft fan blades |
| Answer» B. Excessive fly ash discharge from the stack | |
| 15. |
In salt bath furnace, heat is transferred to the charge mainly by? |
| A. | Conduction |
| B. | Convection |
| C. | Radiation |
| D. | None of these |
| Answer» B. Convection | |
| 16. |
Which furnace employs natural draft? |
| A. | Coke oven |
| B. | Boiler |
| C. | Rotary kilns |
| D. | L.D. converter |
| Answer» B. Boiler | |
| 17. |
Which of the following variables does not affect the furnace capacity? |
| A. | Size of the furnace |
| B. | Gas velocity in furnace |
| C. | Ratio of wall surface to surface of stock |
| D. | None of these |
| Answer» E. | |
| 18. |
Out of the following fuels used in a furnace exhausting flue gas at a temperature of 600°C, the percentage stack loss will be maximum in case of complete combustion of$ |
| A. | Furnace oil with air |
| B. | Furnace oil with oxygen |
| C. | Blast furnace gas with air |
| D. | Blast furnace gas with oxygen |
| Answer» D. Blast furnace gas with oxygen | |
| 19. |
Which of the following variables affects the furnace capacity? |
| A. | Temperature of flue gas |
| B. | Thermal conductivity of stock |
| C. | Thickness of heating stock |
| D. | All of the above |
| Answer» E. | |
| 20. |
Which of the following is not a directly fired furnace? |
| A. | By-product coke oven |
| B. | Calcination kiln |
| C. | Sintering furnace |
| D. | Open hearth furnace |
| Answer» B. Calcination kiln | |
| 21. |
While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about __________ °C.$ |
| A. | 2000 |
| B. | 3000 |
| C. | 4500 |
| D. | 6000 |
| Answer» D. 6000 | |
| 22. |
Presence of SO‚ÇÇ in furnace gases attacks the ferrous metal by way of$ |
| A. | Accelerating the rate of scaling |
| B. | Causing metal embrittlement |
| C. | Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature |
| D. | All of the above |
| Answer» E. | |
| 23. |
Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C.$ |
| A. | 250 |
| B. | 650 |
| C. | 850 |
| D. | 1000 |
| Answer» C. 850 | |
| 24. |
Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C.# |
| A. | 80 |
| B. | 130 |
| C. | 180 |
| D. | 250 |
| Answer» C. 180 | |
| 25. |
Which of the following is a heat treatment furnace? |
| A. | Muffle furnace |
| B. | Annealing furnace |
| C. | Reheating furnace |
| D. | Rotary kiln |
| Answer» C. Reheating furnace | |
| 26. |
In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by# |
| A. | Conduction |
| B. | Convection |
| C. | Radiation |
| D. | Can not be predicted |
| Answer» D. Can not be predicted | |
| 27. |
Which furnace employs preheating, heating and soaking zones? |
| A. | Soaking pit |
| B. | Reheating furnace |
| C. | Open hearth furnace |
| D. | Cupola |
| Answer» C. Open hearth furnace | |
| 28. |
Which one shows the diagramatic heat balance in a furnace? |
| A. | Sankey diagram |
| B. | Cox chart |
| C. | Ostwald chart |
| D. | None of these |
| Answer» B. Cox chart | |
| 29. |
In practical operation of any furnace, zero oxygen percentage or theoretical CO‚ÇÇ percentage in flue gas is rarely achieved, because of# |
| A. | Use of non-preheated combustion air |
| B. | Use of pulverised solid fuels |
| C. | Imperfect mixing of fuel & air and infiltration of air |
| D. | Use of excessive positive draft in the furnace |
| Answer» D. Use of excessive positive draft in the furnace | |
| 30. |
In a furnace operation, which is not preheated? |
| A. | Solid fuels |
| B. | Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.) |
| C. | Both A and B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 31. |
Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percent furnace oil as compared to its combustion with atmospheric air, if the flue gas outlet temperature from the soaking pit is 1200°C.# |
| A. | 5 |
| B. | 60 |
| C. | 20 |
| D. | 40 |
| Answer» D. 40 | |
| 32. |
Which of the following is not a recuperative furnace? |
| A. | Soaking pit |
| B. | Reheating furnace |
| C. | Steamboiler |
| D. | Coke oven |
| Answer» E. | |
| 33. |
Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the |
| A. | physical nature, ash content and fineness of the coal. |
| B. | amount of excess air supplied and load on the boiler. |
| C. | type of burner and combustion chamber. |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 34. |
Which of the following is a batch furnace ? |
| A. | Cupola |
| B. | Reheating furnace |
| C. | Glass tank furnace |
| D. | None of these |
| Answer» B. Reheating furnace | |
| 35. |
Very high pressure boilers are usually __________ boilers. |
| A. | fire tube |
| B. | water tube |
| C. | waste heat |
| D. | natural circulation |
| Answer» E. | |
| 36. |
In low or standard frequency induction furnace, heat is produced by the |
| A. | combination of induced current and skin effect. |
| B. | induction and resistance. |
| C. | current flow through a heating element. |
| D. | none of these. |
| Answer» C. current flow through a heating element. | |
| 37. |
Reverberatory furnace is used for |
| A. | roasting/reduction of ores |
| B. | annealing steel coil |
| C. | heating air |
| D. | steel melting |
| Answer» B. annealing steel coil | |
| 38. |
A refractory wall separating the stock and the source of heat is provided in a |
| A. | updraft kiln |
| B. | muffle furnace |
| C. | continuous furnace |
| D. | none of these |
| Answer» C. continuous furnace | |
| 39. |
The heating capacity of continuous reheating furnace depends upon the |
| A. | hearth area and furnace temperature. |
| B. | emissivity of the stock. |
| C. | ratio of wall surface to stock surface. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 40. |
Regenerators as compared to recuperators for the same duty |
| A. | store smaller quantity of waste heat |
| B. | are lighter & compact |
| C. | involve higher initial cost |
| D. | all (a), (b) & (c) |
| Answer» D. all (a), (b) & (c) | |
| 41. |
Which furnace employs natural draft ? |
| A. | Coke oven |
| B. | Boiler |
| C. | Rotary kilns |
| D. | L.D. converter |
| Answer» B. Boiler | |
| 42. |
Which furnace employs an I.D. fan for the removal of flue gases from the furnace ? |
| A. | Coke oven. |
| B. | Blast furnace stoves. |
| C. | Beehive coke oven. |
| D. | High pressure boiler. |
| Answer» E. | |
| 43. |
If fuel and air are mixed ahead of the burner, it is called a/an __________ burner. |
| A. | premix |
| B. | outside mixing type |
| C. | rotary |
| D. | diffusion |
| Answer» B. outside mixing type | |
| 44. |
Which of the following is the most important deterrants to an extended use of pulverised coal in boiler firing ? |
| A. | Ash disposal problem. |
| B. | Excessive fly ash discharge from the stack. |
| C. | Higher power consumption in its transportation. |
| D. | Erosion of induced draft fan blades. |
| Answer» B. Excessive fly ash discharge from the stack. | |
| 45. |
An example of indirectly heated furnace is the |
| A. | soaking pit |
| B. | muffle furnace |
| C. | reheating furnace |
| D. | none of these |
| Answer» C. reheating furnace | |
| 46. |
Out of the following fuels used in a furnace exhausting flue gas at a temperature of 600°C, the percentage stack loss will be maximum in case of complete combustion of$ |
| A. | furnace oil with air. |
| B. | furnace oil with oxygen. |
| C. | blast furnace gas with air. |
| D. | blast furnace gas with oxygen. |
| Answer» D. blast furnace gas with oxygen. | |
| 47. |
Turn down ratio of a burner |
| A. | should be as low as possible i.e., 1 : 2. |
| B. | should be 1:1 for a batch type furnace.. |
| C. | is the ratio of maximum to minimum permissible heat input rates. |
| D. | is normally much more for a continuous furnace as compared to a batch furnace. |
| Answer» D. is normally much more for a continuous furnace as compared to a batch furnace. | |
| 48. |
Oxygen enrichment of combustion air does not result in increase of the |
| A. | flame temperature. |
| B. | oxygen in the flue gas. |
| C. | stack loss. |
| D. | heat transfer rate in the furnace. |
| Answer» C. stack loss. | |
| 49. |
Turndown ratio of a burner gives an idea of the __________ in the furnace. |
| A. | range of fuel firing rates |
| B. | volume of the combustion chamber |
| C. | maximum heat input rate only |
| D. | minimum heat input rate only |
| Answer» B. volume of the combustion chamber | |
| 50. |
Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace ? |
| A. | Economiser. |
| B. | Regenerator. |
| C. | Ceramic recuperator. |
| D. | Waste heat boiler. |
| Answer» C. Ceramic recuperator. | |