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1) Expanding steam to a very low pressure (high vacuum) in steam engines is _________________? a. desirable b. economical c. essential d. optional e. uneconomical
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2) Reheating of steam under ideal conditions takes place at constant __________________? a. entropy b. enthaply c. pressure d. temperature e. all of the above
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3) Proximate analysis of fuel is determination of percentage of ____________________? a. carbon, hydrogen, nitrogen, sulphur, moisture b. fixed carbon, ash, volatile matter, moisture c. higher calorific value d. lower calorific value e. rough analysis
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4) Bomb calorimeter is used to determine ___________________? a. Higher calorific value at constant volume b. Lower calorific value at constant volume c. Higher calorific value at constant pressure d. Lower calorific value at constant pressure e. None of the above
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5) For combustion of a fuel, following is essential_____________________? a. correct fuel air ratio b. proper ignition temperature c. 02 to support combustion d. all the three above e. none of the above
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6) The economizer is used in boilers to _______________________? a. increase thermal efficiency of boiler b. economise on fuel c. extract heat from the exhaust flue gases d. increase flue gas temperature e. to heat feed water by bled steam
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7) 02 content in atmospheric air on volume basis is___________________? a. 21% b. 23% c. 30% d. 40% e. 70%
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8) Primary air is the air used to__________________? a. provide air around burners for obtaining optimum combustion b. transport and dry the coal c. convert CO (formed in lower zone of furnace) into C02 at higher zone d. air-delivered by forced draft fan e. none ot the above
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9) Presence of moisture in fuel oil would____________________? a. keep the burner tips cool b. aid in proper combustion c. cause sputtering, possibly extinguish¬ing flame d. clean the nozzles e. reduce flame length
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10) Water and sediment in fuel oil can be removed by _______________________? a. heating the oil in the settling tanks b. cooling the oil in the settling tanks c. burning the oil d. suspension e. filtering
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11) Secondary air is the used to_________________? a. provide air around burners for obtaining optimum combustion b. transport and dry the coal c. convert CO (formed in lower zone of furnace) into C02 at higher zone d. air delivered by induced draft fan e. air fed to pulverisers
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12) Caking coals are those which __________________________? a. form lumps or masses of coke b. burn freely c. show little or no fusing action d. burn completely e. do not form ash
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13) The ultimate analysis of fuel lists _____________________? a. various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as per-cents by volume b. various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as per-cents by weight c. fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash d. fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash e. moisture and ash free heating value
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14) Tertiary air is the air used to____________________? a. provide air around burners for obtaining optimum combustion b. transport and dry the coal c. cool the scanners d. supply air for ignitors e. convert CO (formed in lower zone of furnace) into C02 at higher zone
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15) Heating value of fuel used is as on fired basis. If it is reported for dry or moisture free fuel, then latter should be multiplied by the following factor to correct for as fired value ___________________? a. (1- moisture content) b. (1 + moisture content) c. 1 + moisture content d. 1 – moisture content
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16) Incomplete combustion can be best judged by__________________? a. smoky chimney exit b. excess air in flue gases c. measuring carbon mono-oxide in flue gases d. measuring temperature of flue gases at exit of furnace e. measuring oxygen in flue gases
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17) Pulverized fuel is used for___________________? a. better burning b. more calorific value c. less radiation loss d. medium sized units e. stoker fired boilers
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18) Evaporative capacity of boiler is expressed as____________________? a. kg of steam produced b. steam pressure produced c. kg of fuel fired d. kg of steam produced per kg of fuel fifed e. kg of water evaporated
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19) The balanced draft furnace is one using _________________________? a. induced draft fan and chimney b. induced draft fan and forced draft fan c. forced draft fan and chimney d. any one of the above e. none of the above
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20) Maximum energy loss in a boiler occurs due to _______________________? a. unburnt carbon in ash b. incomplete combustion c. ash content d. flue gases e. radiation losses
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