MCQOPTIONS
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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.
| 1101. |
The electric furnace in which heat is produced by a combination of induced current and skin effect is called __________ furnace. |
| A. | arc |
| B. | resistance |
| C. | low frequency induction |
| D. | high frequency induction |
| Answer» E. | |
| 1102. |
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 | |
| 1103. |
Shaft furnaces are used for |
| A. | smelting |
| B. | calcining |
| C. | roasting |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 1104. |
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 | |
| 1105. |
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. | |
| 1106. |
Heat balance of furnace provides means of determining the |
| A. | thermal efficiency of the process. |
| B. | sources of heat losses. |
| C. | scope of reduction of heat losses. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1107. |
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 | |
| 1108. |
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 | |
| 1109. |
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 | |
| 1110. |
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. | |
| 1111. |
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. | |
| 1112. |
Heat transfer takes place through a liquid medium surrounding the submerged material under heating, in case of a/an |
| A. | blast furnace. |
| B. | steam boiler. |
| C. | salt bath furnace. |
| D. | annealing furnace. |
| Answer» D. annealing furnace. | |
| 1113. |
Protective gas used in the annealing furnace for steel coil comprises of |
| A. | 95% N₂ + 5% H₂ |
| B. | 5% H₂ + 9% N₂ |
| C. | 100% CO |
| D. | 100% H₂ |
| Answer» B. 5% H₂ + 9% N₂ | |
| 1114. |
Scaling of furnace stock is reduced by __________ in flue gas. |
| A. | CO |
| B. | H₂ |
| C. | high CO/CO₂ |
| D. | all (a), (b) & (c) |
| Answer» E. | |
| 1115. |
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. | |
| 1116. |
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) | |
| 1117. |
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. | |
| 1118. |
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. | |
| 1119. |
Presence of SO₂ 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 (a), (b) and (c). |
| Answer» E. | |
| 1120. |
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. | |
| 1121. |
Very high pressure boilers are usually __________ boilers. |
| A. | fire tube |
| B. | water tube |
| C. | waste heat |
| D. | natural circulation |
| Answer» E. | |
| 1122. |
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 | |
| 1123. |
Furnace pressure is normally controlled by regulating the |
| A. | air pressure |
| B. | fuel gas pressure |
| C. | speed of I.D. fan |
| D. | damper |
| Answer» E. | |
| 1124. |
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. | |
| 1125. |
Regenerators are normally provided in the |
| A. | glass melting furnace. |
| B. | open hearth furnace. |
| C. | by product coke ovens. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1126. |
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 | |
| 1127. |
Main gas valve in a gaseous fuel burner is a __________ valve. |
| A. | gate |
| B. | butterfly |
| C. | globe |
| D. | none of these |
| Answer» B. butterfly | |
| 1128. |
Which of the following is a rotary furnace? |
| A. | Lime kiln |
| B. | Soaking pit |
| C. | Stoves |
| D. | Annealing furnace. |
| Answer» B. Soaking pit | |
| 1129. |
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. | |
| 1130. |
In order to maintain an oxidising atmosphere in a furnace, it should have |
| A. | more of excess air |
| B. | less of excess air |
| C. | more of CO in flue gas |
| D. | more of CO₂ in flue gas |
| Answer» B. less of excess air | |
| 1131. |
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. | |
| 1132. |
Thermal efficiency of an open hearth furnace may be about __________ percent. |
| A. | 5 |
| B. | 20 |
| C. | 50 |
| D. | 80 |
| Answer» C. 50 | |
| 1133. |
Dampers are located |
| A. | before the I.D fan |
| B. | after the I.D. fan |
| C. | near the top of the chimney |
| D. | anywhere after the I.D. fan |
| Answer» B. after the I.D. fan | |
| 1134. |
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 | |
| 1135. |
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. | |
| 1136. |
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). | |
| 1137. |
Ingress of cold air in the furnaces through cracks, charging doors, openings etc. |
| A. | reduces the flue gas temperature and makes the furnace atmosphere oxidising. |
| B. | increases the load on the induced draft fan. |
| C. | reduces the furnace draught. |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 1138. |
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. | |
| 1139. |
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. | |
| 1140. |
Air filtration in a furnace |
| A. | reduces its thermal efficiency. |
| B. | is indicated by flame sting out. |
| C. | increases the flue gas temperature. |
| D. | none of these. |
| Answer» B. is indicated by flame sting out. | |
| 1141. |
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. | |
| 1142. |
Regenerators compared to the recuperators for the same duty |
| A. | occupy more space |
| B. | are less costly |
| C. | are of smaller size |
| D. | all (a), (b) and (c) |
| Answer» B. are less costly | |
| 1143. |
Rotary kilns are used in the |
| A. | calcination of limestone & dolomite. |
| B. | cement manufacture. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1144. |
Notching is the operation of |
| A. | cutting a sheet of metal in a straight line along the length |
| B. | removal of metal to the desired shape from the edge of a plate |
| C. | cutting a sheet of metal through part of its length and then bending the cut portion |
| D. | bending a sheet of metal along a curved axis |
| Answer» C. cutting a sheet of metal through part of its length and then bending the cut portion | |
| 1145. |
For arc welding |
| A. | alternating current with high frequency is used |
| B. | alternating current with low frequency is used |
| C. | direct current is used |
| D. | any one of these |
| Answer» D. any one of these | |
| 1146. |
V-block is used to |
| A. | check the trueness of flat surfaces |
| B. | locate centres of round rods |
| C. | check the surface roughness |
| D. | none of these |
| Answer» E. | |
| 1147. |
In order to cut mild steel, the cutting angle of chisel should be |
| A. | 30° |
| B. | 45° |
| C. | 50° |
| D. | 60° |
| Answer» E. | |
| 1148. |
A pouring basin acts as a reservoir for the molten metal. |
| A. | Agree |
| B. | Disagree |
| C. | Can't say |
| D. | None of these |
| Answer» B. Disagree | |
| 1149. |
Piercing is an operation of cutting |
| A. | a cylindrical hole in a sheet of metal by the punch and the die |
| B. | a hole (other than cylindrical) in a sheet of metal by the punch and the die |
| C. | a flat sheet to the desired shape |
| D. | a number of holes evenly spaced in a regular pattern on a sheet of metal |
| Answer» C. a flat sheet to the desired shape | |
| 1150. |
The welding process used to join the ends of two pipes of uniform cross-section, is |
| A. | spot welding |
| B. | seam welding |
| C. | projection welding |
| D. | upset butt welding |
| Answer» E. | |