0% 0 Fuels and Combustion Quiz 1 1 / 50 A coal with high ash content_____? Is not subjected to washing Has low quantity of mineral matter Is harder and stronger Has higher calorific value 2 / 50 ______ present in coal is not determined in its ultimate analysis ? Nitrogen Total carbon Hydrogen Fixed carbon 3 / 50 Anthracite coal ______? Is essentially a coking coal Contains more volatile matter than bituminous coal Ignites more easily than bituminous coal Burns with short, bluish, yellow-tipped flame producing very little smoke 4 / 50 A good quality coal should have _____? Low fusion point of ash High ash content High sulphur None of these 5 / 50 Ammonia content in raw coke oven gas is about ______ gm/Nm3? 100 1 50 5 6 / 50 Anthracite can be used for_____? All A., B. and C. Blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke Making carbon electrodes Recarbonising steel 7 / 50 A gaseous fuel in order to develop luminosity on burning, must contain ___________? Oxygen Hydrocarbons Carbon monoxide Hydrogen 8 / 50 ?Micum Index? of a coke is a measure of its_____? Hardness & strength Bulk density Reactivity Porosity 9 / 50 A fuel containing carbon and carbon monoxide (but containing no hydrogen or its compounds) is burnt in pure oxygen at constant pressure. Its gross calorific value as compared to net calorific value will be__________? Less Data insufficient; can?t be predicted Same More 10 / 50 ?Fat coals? are those coals which have very high______? Caking capacity Volatile matter content Inherent moisture content Fusion point of its ash 11 / 50 A certain thickness of the coal, if stored unscientifically on soft (katcha) ground having no metallic/concrete flooring gets sunked into the ground, which is termed as the ?carpet loss?. The carpet loss may be of the order of _______ cms? 1 to 2 20 to 40 3 to 4 5 to 15 12 / 50 A coal containing high amount of volatile matter will have___________? High fusion point of its ash Low ignition temperature Low adiabatic flame temperature Very little ash content 13 / 50 Abel apparatus is used for those oils, whose flash points are ___________?F? 300-600 < 120 > 120 > 280 14 / 50 A coal having higher volatile matter content will necessarily have lower______? Ash fusion temperature Ignition temperature Caking index Calorific value 15 / 50 A coal that softens and fuses on heating is__________? Classified Caking Non-caking Carbonised 16 / 50 Advantages of fluidised bed combustion are ______? All A., B. & C. Reduced NOx formation in flue gas Lower furnace operating temperature High heat transfer rate 17 / 50 ______ has the widest inflammability limit (explosion limit) of all the gases? Hydrogen Acetylene Carbon monoxide Methane 18 / 50 _____ process is meant for direct hydrogenation of coal to produce liquid fuel? Fischer-Tropsch Bergius Lurgi None of these 19 / 50 About ______ Nm3 of air will be required for the complete combustion of 2Nm3 of CO? 2 3 4 5 20 / 50 __________ is used as jet engine fuel ? Diesel Kerosene Petrol LPG 21 / 50 Artificial draught produced by a fan can be controlled by the_____? All A., B. and C. Speed of the fan Damper Variation in the pitch of the fan blades 22 / 50 A coal with high ash content is undesirable, as_________? The ash retains the sulphur & phosphorus and thus affects the quality of products in metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to the boiler tubes thereby reducing the heat transfer The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace and causes its spalling due to different co-efficient of expansion/contraction of the refractory and the ash It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber All A., B. and C. 23 / 50 ______ prohibits the use of alcohols directly in petrol engines ? Low flash point Low octane number Low calorific value High cost & availability 24 / 50 A sample of natural gas containing 80% methane (CH4) and rest nitrogen (N2) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the remainder going to CO, the Orsat analysis in volume percent is__________? CO2 : 6.26, CO : 1.56, O2 : 3.91, H2O :15.66, N2 : 72.60 CO2 : 6.39, CO : 1.60, O2 : 3.99, H2O:25.96, N2:72.06 CO2 : 7.42, CO : 1.86, O2 : 4.64, N2:86.02 CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74 25 / 50 Abrasion index of blast furnace coke should be around ______ percent? 80 55 20 35 26 / 50 A coal having high volatile matter content will _________? Burn with a small non-smoky flame None of these Give less yield of tar and gas on carbonisation Have a very high calorific value 27 / 50 A good metallurgical coke_____? Must contain moderate quantities of ash, moisture, sulphur and volatile matters Should be brittle Should have low fusion point of its ash Should have high porosity 28 / 50 ?Wobbe index? is a characteristic of___________? Liquid fuels Fat coals Solid fuels Gaseous fuels 29 / 50 A travelling grate stoker is meant for the efficient burning of _______ coal? Caking Pulverised High ash Non-caking 30 / 50 A coal gasifier operating at 20 atm. (e.g. Lurgi gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having _______? Lower carbon dioxide content None of these Higher carbon monoxide content Higher methane content and thus higher calorific value 31 / 50 ______ of the coal is the basis for Seylor?s coal classification? Ultimate analysis Caking index Calorific value Proximate analysis 32 / 50 A coal having high amount of volatile matter______? All A., B. and C. Produces very little of tar and gas on carbonisation Would require smaller combustion chamber Ignites easily and burns with long smoky flame 33 / 50 Actual flame temperature is always lower than the adiabatic flame temperature, because there is_________? Neither A. nor B. Both A. and B. No possibility of obtaining complete combustion at high temperature Always loss of heat from the flame 34 / 50 Air/gas ratio for complete combustion will be the highest for___________? LPG Gobar gas Coke oven gas Carburetted water gas 35 / 50 A coal containing very high percentage of durain is called _______ coal? Non-banded Splint Boghead Bright 36 / 50 A coal with high ______ content, would ignite most easily? Fixed carbon Volatile matter Ash Oxygen 37 / 50 A fuel with high heat release rate will__________? Require smaller combustion chamber Have high calorific value None of these Have high adiabatic flame temperature 38 / 50 A particular coal is said to be free burning when it ___________? None of these Burns completely Shows little or no fusing action Gives smokeless burning 39 / 50 ?Fat? coal means a coal having _____? Non smoking tendency High volatile matter Low ash content Low calorific value 40 / 50 ?Wind loss? resulting from unscientific storage of coal may be the order of about ______ percent? 14.5 7.5 2.5 10.5 41 / 50 A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2. It means that_____? Complete combustion of fuel has taken place 21% excess oxygen has been used for combustion 21% excess air has been used for combustion No excess air has been used for combustion 42 / 50 (64-132) rank coal (ASTM) means a coal with 64%_____? Ash and a heating value of 13, 200 BTU/1b None of these Fixed carbon and a heating value of 132 BTU/1b Fixed carbon and having a heat value of 13, 200 BTU/1b 43 / 50 Adiabatic flame temperature of a fuel is dependent on the initial temperature of_____? Both A. & B. Fuel Neither A. nor B. Air 44 / 50 A coal having higher volatile matter content, has lower__________? Chance of catching fire during storage in open space Smoking tendency on burning Coke oven gas yield on carbonisation Ignition temperature 45 / 50 A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon __________? Is more difficult to ignite and produces a shorter flame Requires smaller combustion space and less secondary air None of these Is less liable to spontaneous combustion on storage 46 / 50 64-132) rank coal (ASTM) means a coal with 64%_____? Fixed carbon and heating value around 132 BTU/1b None of these Fixed carbon and having a heating value around 13, 200 BTU/1b Ash and heating value around 13, 200 BTU/1b 47 / 50 ?Fuel? can be defined as a substance which produces heat by_____? All A., B. & C. Combustion Nuclear fission Nuclear fusion 48 / 50 A good coking coal should have high _______ content? Moisture Ash None of these Sulphur & phosphorus 49 / 50 A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the__________? Lack of thorough mixing of fuel with air Presence of large quantity of hydrogen in the fuel High sulphur content in the fuel Low calorific value of the fuel 50 / 50 ?Overfire burning? in a furnace is a phenomenon characterised by the ___________? None of these Supply of excess fuel Supply of excess air Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air Provide Your Information Your score is The average score is 0% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp PrevFluid Mechanics for Chemical Quiz 15 Fuels and Combustion Quiz 3Next
