MCQOPTIONS
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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 751. |
Which of the following is not a recuperative furnace ? |
| A. | Soaking pit |
| B. | Reheating furnace |
| C. | Steamboiler |
| D. | Coke oven. |
| Answer» E. | |
| 752. |
Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace ? |
| A. | Increase in calorific value of the fuel. |
| B. | Increase in flame temperature. |
| C. | Reduction in scale losses. |
| D. | Saving in fuel consumption. |
| Answer» B. Increase in flame temperature. | |
| 753. |
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. | |
| 754. |
Reheating furnace (pusher type) is used for heating |
| A. | ingots |
| B. | slabs |
| C. | steel coils |
| D. | steel sheets |
| Answer» C. steel coils | |
| 755. |
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. | |
| 756. |
Which one is not an induced draught furnace? |
| A. | Blast furnace stove |
| B. | Sintering furnace |
| C. | High pressure boiler |
| D. | None of these |
| Answer» B. Sintering furnace | |
| 757. |
Overfire burning in a furnace is a phenomenon characterised by |
| A. | supply of excess fuel. |
| B. | supply of excess air. |
| C. | burning carbon monoxide and other incombustible in upper zone of furnace by supplying more air. |
| D. | none of these. |
| Answer» D. none of these. | |
| 758. |
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. | |
| 759. |
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. | |
| 760. |
Fuel economy in an industrial furnace operation can not be achieved by the use of |
| A. | stoichiometric combustion air. |
| B. | non-preheated combustion air. |
| C. | combustion air not enriched with oxygen. |
| D. | recupterators. |
| Answer» B. non-preheated combustion air. | |
| 761. |
The function of an economiser in a boiler is to preheat the |
| A. | feedwater |
| B. | combustion air |
| C. | pulverised coal |
| D. | furnace oil |
| Answer» B. combustion air | |
| 762. |
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 | |
| 763. |
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 | |
| 764. |
The rate of scaling of furnace stock depends upon the |
| A. | temperature |
| B. | time |
| C. | nature of atmosphere |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 765. |
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. | |
| 766. |
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). | |
| 767. |
Operation of blast furnace stove is based on the principles of a __________ furnace. |
| A. | regenerative |
| B. | recuperative |
| C. | both (a) and (b) |
| D. | neither (a) nor (b). |
| Answer» B. recuperative | |
| 768. |
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 | |
| 769. |
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 | |
| 770. |
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. | |
| 771. |
An example of recuperative furnace is the |
| A. | soaking pit |
| B. | open hearth furnace |
| C. | coke ovens |
| D. | none of these |
| Answer» B. open hearth furnace | |
| 772. |
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 | |
| 773. |
The advantages of firing pulverised coal in the furnace lies in the fact that, it |
| A. | permits the use of high ash content coal. |
| B. | permits the use of low fusion point ash coal. |
| C. | accelerates the burning rate and economises on fuel consumption. |
| D. | all (a), (b) and (c). |
| Answer» D. all (a), (b) and (c). | |
| 774. |
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 | |
| 775. |
If the flame is produced under the hearth and then sweeps up into the heating chamber, this is called a/an __________ furnace. |
| A. | sidefired |
| B. | underfired |
| C. | covered |
| D. | recirculating |
| Answer» C. covered | |
| 776. |
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. | |
| 777. |
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 | |
| 778. |
Advantages of use of preheated combustion air are |
| A. | saving in fuel consumption. |
| B. | reduction in scale losses. |
| C. | increase in flame temperature. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 779. |
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. | |
| 780. |
Circulation of gases in furnace is caused by the |
| A. | change in volume during a change of temperature. |
| B. | difference in density between hot and cold gases. |
| C. | furnace pressure in conjunction with draft in flues. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 781. |
Furnace aerodynamics is related to the __________ in the furnace. |
| A. | movement of gases |
| B. | measurement of flue gas volume |
| C. | temperature control |
| D. | pressure adjustment |
| Answer» B. measurement of flue gas volume | |
| 782. |
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. | |
| 783. |
Which furnace employs natural draft ? |
| A. | Coke oven |
| B. | Boiler |
| C. | Rotary kilns |
| D. | L.D. converter |
| Answer» B. Boiler | |
| 784. |
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 | |
| 785. |
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 | |
| 786. |
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 | |
| 787. |
Blast furnace stoves are meant for heating |
| A. | air |
| B. | blast furnace gas |
| C. | steam |
| D. | none of these |
| Answer» B. blast furnace gas | |
| 788. |
Fuel economy in furnaces can be achieved by |
| A. | using oxygen enriched combustion air. |
| B. | preheating the combustion air. |
| C. | reducing the heat loss through furnace openings & doors. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 789. |
Thermal efficiency of an open hearth furnace may be about __________ percent. |
| A. | 5 |
| B. | 20 |
| C. | 50 |
| D. | 80 |
| Answer» C. 50 | |
| 790. |
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 | |
| 791. |
Maximum thermal efficiency of boiler may be about __________ percent. |
| A. | 10 |
| B. | 25 |
| C. | 65 |
| D. | 90 |
| Answer» E. | |
| 792. |
Rotary kilns are used in the |
| A. | calcination of limestone & dolomite. |
| B. | cement manufacture. |
| C. | both (a) and (b). |
| D. | neither (a) nor (6). |
| Answer» D. neither (a) nor (6). | |
| 793. |
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 (a), (b) and (c). |
| Answer» E. | |
| 794. |
In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the |
| A. | rate of firing and emissivity of flame. |
| B. | thermal conductivity of the charge & structural materials of furnace. |
| C. | nature of process ; whether batch, continuous or intermittant. |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 795. |
The heating capacity of muffle furnace depends on the |
| A. | surface area & emissivity of the stock. |
| B. | properties of the muffle wall (temperature, area, emissivity). |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 796. |
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 | |
| 797. |
In a heating process, a heat flow diagram in which the quantities of heat in the various items of a heat balance are represented by the width of a band is called the |
| A. | Ostwald chart |
| B. | Cox chart |
| C. | Sankey diagram |
| D. | none of these |
| Answer» D. none of these | |
| 798. |
Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an |
| A. | economiser |
| B. | steam superheater |
| C. | air preheater |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 799. |
In which of the following furnaces, the gases are sucked through the stock bed from below? |
| A. | Soaking pit |
| B. | Sintering machine |
| C. | Beehive oven |
| D. | None of these |
| Answer» C. Beehive oven | |
| 800. |
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 | |