Fuels and Combustion Terms
100. Hydrocarbons with 5 to 15 carbon atoms are A. more or less volatile light oils B. referred to as heavy oils С. mixtures of many kinds of hydrocarbons D. commercial fuels Answer:
A
12. PAST BOARD QUESTION Which of the following is the type of solid injection that uses single pump to supply fuel under high pressure to a fuel header? A. Common rail injection B. Individual pump injection system C. Distributor system D. Single rail injection Answer:
A
13. PAST BOARD QUESTION It is known as the cooling where water flow in diesel engine due to its density differential. A. Thermosiphon cooling B. Thermostat cooling C. Pressurized water cooling D. Evaporative water cooling Answer:
A
16. PAST BOARD QUESTION In a spark ignition engine, the detonation occurs near the A end of combustion B. middle of combustion C. beginning of combustion D. beginning of compression
A
23. PAST BOARD QUESTION The internal combustion engines never work in A. B. C. D. Rankine cycle Diesel cycle Dual combustion cycle Otto cycle
A
25. PAST BOARD QUESTION If monatomic gas is used, what will happen to the therma efficiency of Otto cycle? A. increases B. decreases C. remains constant D. nothing happens Answer:
A
33. PAST BOARD QUESTION If the cutoff ratio decreases, what will happen to the efficiency of diesel cycle? A. increases B. decreases C. remains constant D. slightly decreases Answer:
A
36. PAST BOARD QUESTION Which of the following is the chemical formula for Heptane?
A
40. PAST BOARD QUESTION An Orsat apparatus is used for A. volumetric analysis of the flue gases B. gravimetric analysis of the flue gases С. smoke density analysis of the gases D. all of these
A
42. PAST BOARD QUESTION Amount of heat liberated by the complete combustion of a unit weight or volume of fuel is. A. heating value B. latent heat С. sensible heat D. work of compression
A
44. PAST BOARD QUESTION Which of the following statement is true? 44. PAST BOARD QUESTION Which of the following statement is true? A. The ignition of a diesel fuel can be improved by the addition of small percentage of more easily ignitable hydrocarbons B. The ignition quality of a gasoline fuel measured by an index called cetane number C. The ignition quality of a diesel engine is measured by an index called octane number D. None of these
A
48. PAST BOARD QUESTION Air that controls the rate of combustion in the combustion chamber is known as A. secondary air B. excess air C. control air D. primary air Answer:
A
53. PAST BOARD QUESTION Amount of heat liberated by the complete combustion of a unit weight or volume of fuel is A. heating value B. latent heat C. sensible heat D. work of compression
A
54. PAST BOARD QUESTION These are the products of complete combustion o gaseous hydrocarbons. Carbon dioxide and water Carbon monoxide Carbon monoxide, water and ammonia Water, carbon monoxide and carbon dioxide
A
55. PAST BOARD QUESTION When the water in the products of combustion is in the vapor state, the heating value is called A. lower heating value B. higher heating value C. gross calorific value C. D. average heating value
A
56. PAST BOARD QUESTION At what temperature wherein an oil of any grade becomes cloudy and it freezes, thus; its application is limited. A, Cold point B. Flash point C, Pour point D. Freezing point
A
60. PAST BOARD QUESTION Which of the following petrole flashpoint not below 22.8°C ? A. Kerosene B. Alcohol C. Gasoline D. Diesel Answer:
A
63. PAST BOARD QUESTION When H20 in the products of combustion is in liquid form, the heating value is known as A. higher heating value B. lower heating value C. low and medium heating value D. average heating value
A
67. PAST BOARD QUESTION A property of lubricating oil that measures the thickness of the oil and will help determine how long oil will flow at a given temperature is known as A. viscosity B. flash point С. cloud point D. pour point Answer:
A
68. PAST BOARD QUESTION How do you call the time by which it takes to heat the fuel particles, turn them into vapor, and start combustion? A. ignition delay B. lag time C. recuperation D. pre-ignition time
A
74. PAST BOARD QUESTION Which of the following contains 90% gasoline and 10% ethanol. A. Gasohol B. Gasonol C. Gasothanol D. Gasethanol Answer:
A
78. PAST BOARD QUESTION The, temperature at which lubricating will form a cloud. A. Cloud point B. Pour point С. Critical point D. Boiling point Answer:
A
87. PAST BOARD QUESTION When 1 gram of sample of coal is placed in a crucible and heated 950°C and maintain at that temperature for 7 minutes there is a loss in weight due to elimination of which of the following? A. volatile matter and moisture B. ash C. Fixed carbon and sulfur D. moisture content Answer:
A
90. PAST BOARD QUESTION Caking coal are used to produce coke by heating in a coke oven in the absence of with volatile matter driven off. A. Air B. Oxygen Answer: C. oil and Sulfur D. Nitrogen
A
93
A
96
A
98
A
PAST BOARD QUESTION Percent excess air is the difference between the air actually supplied and the theoretically required divided by. A. the theoretically air supplied B. the actually air supplied C. the deficiency of air supplied D. the sufficient air supplied
A
PAST BOARD QUESTION What are the immediate undesirable products from the petroleum based lubricating oil when subjected to high pressure and temperature? Gums, resins and acids Sulfur Soots and ashes Carbon residue
A
11. PAST BOARD QUESTION Oil is atomized either by air blast or pressure jet at about A. 60 bar B. 70 bar C. 80 bar D. 50 bar Answer:
B
15. PAST BOARD QUESTION Which of the following produces extreme pressure differentials and violent gas vibration? A. Vibration B. Detonation C. Explosion D. Knocking Answer:
B
20. PAST BOARD QUESTION The type of filter where the filtering elements is replaceable. Paper edge filter Metal edge filter Pressure filter Filter with element
B
26. PAST BOARD QUESTION In diesel engine, combustion process occurs during what process? A. isothermal process B. constant pressure process C. isentropic process D. adiabatic process Answer:
B
27. PAST BOARD QUESTION What air pressure is needed for air starting a diesel engine? 27. PAST BOARD QUESTION What air pressure is needed for air starting a dir engine? 350 psi 250 psi 450 psi 150 psi
B
28. PAST BOARD QUESTION Mechanical energy of pressure transformed into energy of heat A. Kinetic energy B. Enthalipy C. Heat exchanger D. Heat of compression
B
29. PAST BOARD QUESTION Ignition of the air - fuel mixture in the intake of the exhaust manifold. Backlash Backfire Exhaust pressure Back pressure
B
30. PAST BOARD QUESTION The total sulfur content in a diesel fuel must not exceed A. 0.3 % B. 0.5 % C. 0.8 % D. 0.11% Answer:
B
32. PAST BOARD QUESTION The color of lubricating oil A. does not indicate contamination B. does not indicate qualities С. indicates qualities D. indicates viscosity
B
39. PAST BOARD QUESTION Most commercially available petroleum lubricating oil deteriorates starting from what operating temperature? A. 150 °F B. 200 °F C. 300 °F D. 250 °F
B
49. PAST BOARD QUESTION Percentage of excess air is the difference between the air actually supplied and the theoretically required - divided by. A. actual air supplied B. theoretical air supplied C. theoretical less actual supplied D. deficient air supplied Answer:
B
52. PAST BOARD QUESTION Which of the following gases is produced by the combustion of fuel oil and cannot be found in the flue gases? A. carbon dioxide B. hydrogen C. oxygen D. nitrogen
B
59. PAST BOARD QUESTION Which of the following is the gas produced in the combustion of'fuel oil and cannot be found in the flue gasses? A. oxygen B. hydrogen C. carbon dioxide D. nitrogen Answer:
B
70. PAST BOARD QUESTION Which of the following is lowest grade of coal? A. Peat B. Lignite C. Sub-bituminous D. Bituminous coke Answer:
B
72. PAST BOARD QUESTION What is the ratio of fixed carbon and volatile matter? A. air-fuel ratio B. fuel ratio C. combustion ratio D. carbon-volatile ratio Answer:
B
73. PAST BOARD QUESTION It is the suspension of a finely divide fluid in another. A. filtration B. emulsion C. floatation D. separation Answer:
B
76. PAST BOARD QUESTION Which of the following is an organic matter produced by plants in both land and water? A. Bio-ethanol B. Biomass C. Petroleum D. Biogradable Answer:
B
79. PAST BOARD QUESTION The ideal cycle based on the concept that the combustion process is both diesel and gasoline in the combination of heat transfer processes that is constant pressure and constant volume. A. Ericsson cycle B. Dual cycle C. Brayton cycle D. Rankine cycle
B
8. PAST BOARD QUESTION What fuel is used in a power plant during peak periods? A. gas B. liquid C. solid D. nuclear
B
83. PAST BOARD QUESTION Morse test is used to measure cylinder engine. A. Brake power B. Indicated power C. Friction power D. Motor power loss
B
89. PAST BOARD QUESTION Which of the following will formed by heating 1 gram of coal in an uncovered crucible until the coal is completely burned? A. volatile matter and moisture B. Ash C. Fixed carbon D. moisture content Answer:
B
9. PAST BOARD QUESTION The fuel injection process in diesel engine starts when the piston A. is at the TDC B. approaches TDC C. leaves TDC D. halfway of the stroke
B
91. PAST BOARD QUESTION What is the grindability of standard coal? A. 80 B. 100 Answer: C. 90 D. 110
B
99
B
PAST BOARD QUESTION The viscosity of most commercially available petroleum lubricating oil changes rapidly above
B
PAST BOARD QUESTION When 1 mol carbon combines with 1 mol oxygen A. 2 mols carbon dioxide B. 1 mol carbon dioxide C. 1 mol carbon and 1 mol carbon dioxide D. 1 mol carbon dioxide
B
10. PAST BOARD QUESTION What is the typical compression ratio of Otto cycle? A. 6 B. 10 C. 8 D. 12
C
17. PAST BOARD QUESTION In a compression ignition engine, the detonation occurs near the A. end of combustion B. middle of combustion C. beginning of combustion D. middle of interaction Answer:
C
21. PAST BOARD QUESTION When four events takes place in one revolution of a crankshaft of an engine, the engine is called rotary engine steam engine two stroke engine four stroke engine
C
22. PAST BOARD QUESTION Which of the following does not belong to the group? Air injection system Mechanical injection system Time injection system Gas admission system
C
34. PAST BOARD QUESTION During a combustion process, how do you call the components which exist before the reaction? A. reaction B. combustion C. reactants D. product of combustion
C
37. PAST BOARD QUESTION Enthalpy of substance at specified state due to chemical composition. A. Enthalpy of reaction B. Enthalpy of combustion C. Enthalpy of formation D. Enthalpy of product Answer:
C
41. PAST BOARD QUESTION This is the indicator used to determine the anti-knock characteristics of gasoline. Aniline point Cetane number Octane number Diesel index
C
43. PAST BOARD QUESTION Which of the following is the chemical formula for Ethanol?
C
47. PAST BOARD QUESTION Which of the following is the chemical formula for Toluene?
C
57
C
58. PAST BOARD QUESTION This is the lowest temperature to which an oil must be heated in order to give off inflammable vapors in a sufficient amount to momentarily ignite when brought in contact with a flame. A. pour point B. fire point C. flash point D. torch point Answer:
C
62. PAST BOARD QUESTION The processes by which the mixture of oil and water does not separate into its components, (i.e. oil and water ). A. mixture B. suspension C. emulsion D. coagulation Answer:
C
66. PAST BOARD QUESTION This is the property of liquid by which it extends resistance to angular or shear deformation. specific gravity specific weight viscosity density
C
75. PAST BOARD QUESTION Which of the following is the process used commercially in coal liquefaction? A. Tropsch process B. Fischer process C. Fischer-Tropsch process D. Mixed-Tropsch process Answer:
C
77. PAST BOARD QUESTION The minimum amount of air required for a complete combustion of fuel is called A. dry air B. excess air C. theoretical air D. flue gas Answer:
C
81. PAST BOARD QUESTION What is the distance between TDC and BDC in which the piston can travel ? A. right extreme position B. displacement stroke C. stroke of the engine D. swept stroke Answer:
C
84
C
85. PAST BOARD QUESTION What is the largest group of coal containing 46-86% di fixed carbon and 20 to 40% volatile matter? A. Anthracite B. Sub-anthracite C. Bituminous D. Sub-bituminous Answer:
C
92. PAST BOARD QUESTION What is the major constituent of all natural gases? A. ethane C. methane B. propane D. pentane Answer:
C
94
C
95
C
97
C
14. PAST BOARD QUESTION Type of lubrication system in diesel engine in which oil from pump is carried to a separate storage tank outside the engine cylinder and used for high capacity engine. A. Mist lubrication system B. Wet sump lubrication system C. Splash lubrication system D. Dry sump lubrication system Answer:
D
18. PAST BOARD QUESTION Loss power is due to A. poor compression B. restricted exhaust C. clogging of air cleaner D. low injection pressure
D
19. PAST BOARD QUESTION How do you call a branch system of pipes to carry waste emissions away from the piston chambers of an internal combustion engine? exhaust nozzle B. exhaust deflection pipe С. exhaust pipe D. exhaust manifold
D
24. PAST BOARD QUESTION The thermal efficiency of an ideal Otto cycle depends on A. the pressure ratio of the engine and the specific heat ratio of the working fluid B. the temperature ratio of the engine and the specific heat ratio of the working fluid C. the moles ratio of the engine and the temperature of the working fluid D. the compression ratio of the engine and the specific heat ratio of the working fluid
D
3. PAST BOARD QUESTION What is the apparatus used in the analysis of combustible gases? A. Calorimeter differential B. Calorimeter gas C. Calorimetry D. Calorimeter
D
31. PAST BOARD QUESTION When crude oil is heated, then which one of the following hydrocarbon is given off first? A. gasoline B. paraffin C. diesel D. natural gas
D
35. PAST BOARD QUESTION Which of the following is an obvious reason for incomplete combustion? A. Insufficient carbon B. Insufficient air C. Insufficient nitrogen and hydrogen D. Insufficient oxygen Answer:
D
38. PAST BOARD QUESTION There are two broad types in the classification of lubricating oils, these are straight and A. active B. inactive C. crooked D. additives Answer:
D
45. PAST BOARD QUESTION Which of the following is the chemical, formula for Hexene?
D
46. PAST BOARD QUESTION Higher heating value of fuel is determine when H2O in the product of combustion is in A. solid form B. vapor form C. gaseous form D. liquid form Answer:
D
50. PAST BOARD QUESTION When fuel oil has a high viscosity then the fuel oil A. will evaporate easily B. will have a low specific gravity C. will burn without smoke D. will flow slowly through pipes
D
51. PAST BOARD QUESTION Engines using heavy fuels require heating of the fuel so that the viscosity at the injector is around 200 SSU 100 SSU or less 200 SSU + 50 150 SSU or slightly higher
D
61. PAST BOARD QUESTION Which of the following properties that influence the performance and reliability of diesel fuel? A. Volatility B. Carbon residue C. Viscosity D. All of these Answer:
D
64. PAST BOARD QUESTION This is the flow of fluids wherein its particles do not have definite paths and the paths of the individual and distinct particles cross one another. A. Non-uniform flow B. Unsteady flow С. Laminar flow D. Turbulent flow Answer:
D
69. PAST BOARD QUESTION This is the type of coal formed after anthracite. A. Lignite B. Bituminous C. Peat D. Graphite
D
71. PAST BOARD QUESTION Which of the following helps in the ignition of coal? A. moisture or vapor B. ash C. fixed carbon D. volatile matter Answer:
D
80. PAST BOARD QUESTION It is the average pressure on a surface when a changing pressure condition exist. A. back pressure B. partial pressure B. C. pressure drop C. D. mean effective pressure
D
82. PAST BOARD QUESTION In compression-engine, the combustion of air-fuel mixture is self-ignited as a result of compressing the mixture above its A. self developed temperature B. mixing temperature C. self-sustaining fed temperature D. self ignition temperature Answer:
D
86. PAST BOARD QUESTION When 1 gram of coal is subjected to a temperature of about 105°C for a period of 1 hour, the loss in weight of the sample gives the A. volatile matter B. ash and sulfur C. fixed carbon D. moisture content Answer:
D
88. PAST BOARD QUESTION Which of the following that consists of hydrogen and certain hydrogen carbon compounds which can be removed from coal by heating? A. Moisture content B. Product of combustion C. Ash D. volatile matter Answer:
D
PAST BOARD QUESTION Percent excess air is the difference between the air actually supplied and the theoretical air divided by A. the sufficient air supplied B. the deficiency air supplied C. the actually air supplied D. the theoretically air supplied
D
PAST BOARD QUESTION Which is not a viscosity rating? A. Redwood B. SSU C. Centipoise D. Entropy Degrees API
D
65. PAST BOARD QUESTION If the composition of hydrocarbon fuel is known, the ratio between the nitrogen and oxygen that is supplied in air is A. equal B. constant С. intensity D. Fixed
b