MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 2171 Mcqs, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1501. |
Decarburisation of steel |
| A. | is the removal of carbon from iron carbide (Fe₃C). |
| B. | affects its crystalline structure. |
| C. | is favoured by CO₂. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1502. |
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 | |
| 1503. |
Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent. |
| A. | < 2 |
| B. | < 5 |
| C. | < 8 |
| D. | < 10 |
| Answer» B. < 5 | |
| 1504. |
Unit of furnace loading is |
| A. | ton stock/hr/m² hearth area |
| B. | ton stock/hr |
| C. | ton stock/m² hearth area |
| D. | both (b) and (c) |
| Answer» B. ton stock/hr | |
| 1505. |
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. | |
| 1506. |
Tunnel kilns are usually used for |
| A. | roasting of pyrites. |
| B. | drying/tempering of refractories. |
| C. | reheating of slabs. |
| D. | melting of glass. |
| Answer» C. reheating of slabs. | |
| 1507. |
The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about __________ percent. |
| A. | 15 |
| B. | 40 |
| C. | 70 |
| D. | 85 |
| Answer» C. 70 | |
| 1508. |
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 | |
| 1509. |
Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by |
| A. | preheating the combustion air. |
| B. | oxygen enrichment of combustion air. |
| C. | preheating the fuel gas. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 1510. |
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 | |
| 1511. |
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 | |
| 1512. |
Pulverised fuel fired furnaces employ __________ fuel firing. |
| A. | horizontal |
| B. | vertical |
| C. | tangential |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 1513. |
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. | |
| 1514. |
In which of the waste heat recovery equipment, the flow of flue gas and air is alternately reversed after a fixed interval of time ? |
| A. | Recuperator |
| B. | Regenerator |
| C. | Waste heat boiler |
| D. | None of these |
| Answer» C. Waste heat boiler | |
| 1515. |
Large tonnage of refractory bricks are dried in a |
| A. | shaft furnace |
| B. | rotary hearth furnace |
| C. | tunnel kiln |
| D. | muffle furnace |
| Answer» D. muffle furnace | |
| 1516. |
Which of the following is not a recuperative furnace ? |
| A. | Soaking pit |
| B. | Reheating furnace |
| C. | Steamboiler |
| D. | Coke oven. |
| Answer» E. | |
| 1517. |
Heat transfer rate to the stock/charge in the furnace does not depend upon the |
| A. | emissivity of the refactory walls. |
| B. | size of the furance. |
| C. | use of waste heat recovery equipments. |
| D. | thickness of the stock. |
| Answer» D. thickness of the stock. | |
| 1518. |
An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called __________ furnace. |
| A. | resistance |
| B. | arc |
| C. | low frequency induction |
| D. | none of these |
| Answer» C. low frequency induction | |
| 1519. |
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 | |
| 1520. |
Which of the following is a periodic furnace? |
| A. | Tunnel kiln |
| B. | Rotary kiln |
| C. | Soaking pit |
| D. | Reheating furnace. |
| Answer» D. Reheating furnace. | |
| 1521. |
Power required in case of forced draught as compared to induced draught (for the same draught produced) is |
| A. | same |
| B. | less |
| C. | more |
| D. | either more or less; depends on the flue gas density |
| Answer» C. more | |
| 1522. |
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 | |
| 1523. |
Ceramic recuperators compared to metallic recuperators for the same duty |
| A. | are lighter. |
| B. | occupy more space. |
| C. | are less costly. |
| D. | have higher pressure differential between flue gas & air side. |
| Answer» C. are less costly. | |
| 1524. |
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 | |
| 1525. |
Example of an indirectly heated furnace is |
| A. | hood annealing furnace |
| B. | muffle furnace |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1526. |
Thickness of stock does not affect the fuel economy of furnaces, if the material to be heated is of |
| A. | low emissivity |
| B. | high thermal conductivity |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1527. |
Calcination of limestone to produce lime is done in a __________ kiln. |
| A. | tunnel |
| B. | rotary |
| C. | vertical shaft |
| D. | both (b) and (c) |
| Answer» E. | |
| 1528. |
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 | |
| 1529. |
An example of a periodic furnace is the |
| A. | blast furnace stoves |
| B. | blast furnace |
| C. | coke oven heating chamber |
| D. | rotary kilns |
| Answer» B. blast furnace | |
| 1530. |
In reverberatory furnace, charge is heated mainly by |
| A. | conduction. |
| B. | natural convection. |
| C. | radiation of heat from the roof of the combustion chamber. |
| D. | none of these. |
| Answer» D. none of these. | |
| 1531. |
Maximum heat transfer in high temperature furnaces is by |
| A. | conduction |
| B. | convection |
| C. | radiation |
| D. | either (a), (b) or (c); depends on the type of furnace |
| Answer» D. either (a), (b) or (c); depends on the type of furnace | |
| 1532. |
Ostwald charts are meant for |
| A. | computing the excess/deficiency of combustion air. |
| B. | calculation of flue gas temperature. |
| C. | computation of flue gas analysis. |
| D. | none of these. |
| Answer» B. calculation of flue gas temperature. | |
| 1533. |
Maximum thermal efficiency of boiler may be about __________ percent. |
| A. | 10 |
| B. | 25 |
| C. | 65 |
| D. | 90 |
| Answer» E. | |
| 1534. |
Use of pulverised coal in boilers provides |
| A. | higher calorific value |
| B. | better combustion |
| C. | smokeless burning |
| D. | less erosion on furnace wall. |
| Answer» C. smokeless burning | |
| 1535. |
The method of Lobo and Evans is concerned with the calculation of the |
| A. | heat absorption in radiant section of a furnace. |
| B. | heat transfer by forced convection in a reboiler. |
| C. | heat transfer in vacuum condensers. |
| D. | mass transfer co-efficient. |
| Answer» B. heat transfer by forced convection in a reboiler. | |
| 1536. |
In practical operation of any furnace, zero oxygen percentage or theoretical CO₂ 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. | |
| 1537. |
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. | |
| 1538. |
Specific heating capacity of a furnace is expressed as |
| A. | weight heated/hr |
| B. | weight heated/furnace volume |
| C. | weight heated/hr/furnace volume |
| D. | none of these |
| Answer» D. none of these | |
| 1539. |
Higher furnace temperature can not be achieved by use of a lean fuel gas in the furnace by |
| A. | increasing the draft in the furnace. |
| B. | preheating the fuel gas. |
| C. | oxygen enrichment of combustion air. |
| D. | preheating the combustion air. |
| Answer» B. preheating the fuel gas. | |
| 1540. |
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. | |
| 1541. |
To reduce the stack loss, heat recovery from flue gas can be done by |
| A. | preheating of cold stock. |
| B. | preheating of combustion air. |
| C. | steam generation in waste heat boilers. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1542. |
Blast furnace stoves are meant for heating |
| A. | air |
| B. | blast furnace gas |
| C. | steam |
| D. | none of these |
| Answer» B. blast furnace gas | |
| 1543. |
An improved and fuel efficient version of the pusher type reheating furnace is the __________ furnace. |
| A. | walking beam |
| B. | shaft |
| C. | tunnel |
| D. | rotary hearth |
| Answer» B. shaft | |
| 1544. |
__________ furnace is not an electric furnace. |
| A. | Arc |
| B. | Induction |
| C. | Pot |
| D. | Resistance. |
| Answer» D. Resistance. | |
| 1545. |
Combustion of fuel in a furnace with oxygen enriched air results in higher |
| A. | flue gas volume |
| B. | flame temperature |
| C. | fuel consumption |
| D. | stack loss |
| Answer» C. fuel consumption | |
| 1546. |
The main function of a muffle in the muffle furnace is to |
| A. | protect the charge from the effects of the products of combustion. |
| B. | smooth out temperature inequalities on the combustion side of the muffle wall. |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1547. |
Reheating furnace (pusher type) is used for heating |
| A. | ingots |
| B. | slabs |
| C. | steel coils |
| D. | steel sheets |
| Answer» C. steel coils | |
| 1548. |
Size of the combustion chamber of a furnace depends upon the |
| A. | heat release rate of the fuel. |
| B. | preheat temperature of fuel & air. |
| C. | method of mixing the fuel & air. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1549. |
Fuel used in B.F. stove is |
| A. | pulverised coal |
| B. | furnace oil |
| C. | blast furnace gas/mixed gas |
| D. | coke oven gas |
| Answer» D. coke oven gas | |
| 1550. |
Recuperator is |
| A. | not used for fuel gas preheating. |
| B. | an intermittant waste heat recovery equipment. |
| C. | a continuous waste heat recovery equipment. |
| D. | heavier than regenerator meant for the same duty. |
| Answer» D. heavier than regenerator meant for the same duty. | |