1. In the Lean mixturers used for automobile applications
Correct : B. air quantity is more than stoichiometric quantity
2. Stoichiometric air fuel ratio suggests
Correct : C. correct quantity of fuel -air ratio which gives complete combustion
3. Practical limits of air fuel ratio for combution in SI engines is
Correct : A. 9 to 21
4. Practical limits of fuel air ratio for combution in SI engines is
Correct : A. 0.11 to 0.05
5. Practical limits for air fuel ratio in SI engines provides
Correct : B. range of air fuel ratio to get combustion close to stochiometric conditions in si engine
6. SI engine is also called as
Correct : D. all of the above
7. SI engine is also called as
Correct : C. otto engine
8. Ignition limits in the SI engine depends upon
Correct : A. mixture ratio and temperature
9. Correct sequence of combustion stages in SI engine is
Correct : B. preparation phase,propagation of flame and after burning
10. Maximum pressure pobtained in SI engine duering motoring is about
Correct : C. 8 bar
11. Pressure during motoring in SI engine compared to CI engine is
Correct : A. less
12. Maximum pressure in SI engine is about
Correct : D. 30 bar
13. SI engine contains homogeneous mixture of
Correct : C. vaporized fuel,air and residual gases
14. Approximate tempearture between electrodes of spark plug is
Correct : D. 10,000 deg. celsius
15. Flame advancement from the start of formation of first nucleus of combustion depends on
Correct : A. temperature of flame front itself, density of surrounding mixture and temperature inside of cylinder.
16. The preparation phase in SI engine will take about
Correct : A. 20 deg. of crank angle
17. The peak pressure in SI engine will be observed when crank angle is
Correct : B. about 10 deg. after tdc
18. The first phase of combustion in SI engine is named as
Correct : C. both a and b
19. In the ignition lag phase of SI engine following things happens
Correct : A. growth and development of semi propagating nucleus of flame.
20. Ignition lag in SI engine depends on following parameters
Correct : D. both b and c
21. Temperature Coeficient of the fuel is
Correct : B. relation between temperature and the rate of acceleration of oxidation or burning.
22. Ignition lag phase is also
Correct : C. chemical process
23. Start of second phase in the combustion of SI engine is indicated by
Correct : D. separation of combustion curve from motoring curve on p-Ө diagram.
24. Separation of combustion curve from motoring curve in SI engine takes place
Correct : A. when crank angle is about 10 deg. before tdc
25. First measurable rise of pressure in SI engine takes place approximately
Correct : B. when crank angle is about 10 deg. before tdc
26. Maximum heat energy is liberated during
Correct : C. propagation of flame
27. Which phase of combustion takes place during expansion stroke
Correct : D. after burning
28. During propagatuion of flame in SI engine crank rotates by about
Correct : A. 20 deg.
29. During afterburning phase in SI engine crank rotates by about
Correct : C. 170 deg.
30. During combustion in SI engine heat is liberated due to reassociation of molecules in
Correct : D. after burning
31. Gap size in spark plug electrodes is about
Correct : B. 1 to 2 mm
32. A-fuel mixture in the SI engine is prepared
Correct : C. prepared in the carburetor outside the cylinder
33. Volatility property of the fluid helps in
Correct : C. can increase or decrease vaporization
34. During combustible mixture preparation process fuel droplets are vaporized in
Correct : C. carburetor, intake manifold and cylinder
35. Maximum fuel economy occurs on the side of following air fuel ratio
Correct : B. large value of air-fuel ratio
36. The important factors which significantly affects process of carburetion are
Correct : D. all of the above
37. The important factors which significantly affects process of carburetion are
Correct : D. both a and d
38. For high speed S I engines following things occurs
Correct : A. less time available for mixture preparation
39. Volatility of the fuel affects following processes in S I engine
Correct : C. both a and b
40. Stoichiometric condition in S I Engine is such that
Correct : D. both b and c
41. When SI engine is Idling
Correct : C. richer mixture is required
42. Idling condition of the SI engine is
Correct : A. when engine is running but no power out put from crank shaft
43. When SI Engine is idling mixture enrichment is done
Correct : B. for compensating diluted mixture in the cylinder because of exhaust gases in the cylinder which remains in previous stroke.
44. For full load on S I engine following changes should be made in mixture prparation
Correct : A. mixture should be prepared with fuel quantity increased
45. During cruising of S I engine
Correct : B. leaner mixture is required
46. With increasing Air-Fuel ratio in S I engine Maximum power
Correct : C. first increases up to a point at which maximum power is obtained and then it is decreases on the leaner side of the mixture
47. Maximum efficiency from the S I engine can be obtained
Correct : D. in the region of richer air-fuel ratio compared to stoichiometric conditions
48. Fuel economy from the engine can be expected
Correct : A. when engine is running at normal speed
49. Fuel economy should not be expected in SI engine for which following cases
Correct : C. both a and b
50. Cruising speed of S I engine is
Correct : B. normal working condition of an engine
51. For Full throttle valve opened condition of an S I engine
Correct : D. we get maximum brake horse power
52. Air-fuel mixture required for condition of best fuel economy and maximum power is
Correct : D. none of the above
53. For proper working of S I engine, I . There is always combustible range II. No proper combustible range can be decided III. Richer mixture is always prepared IV. Leaner mixture is always prepared
Correct : C. statement i is correct
54. For producing maximum power excess fuel burning leads to
Correct : D. both a and b
55. Carburator is used to
Correct : A. meter air-fuel quantity
56. Carburetor is designed
Correct : B. to meter the liquid quantity to prepare the required air-fuel mixture which varies with load on engine
57. In S I Engine homogeneous mixture is prepared in
Correct : C. carburetor
58. Air- fuel ratio must be changed with following conditions of an SI engine
Correct : D. all of the above
59. Steady operating conditions of an SI engine is
Correct : A. continuous operation of engine at constant speed and for constant load on engine
60. For normal power range following air fuel ratio is prefered
Correct : B. 17 to 1
61. During cruising range of operation of SI engine throttle position is opened by
Correct : B. 20 to 78 %
62. During normal operating condition of engine load on engine shoud be
Correct : C. 50% of rated load
63. During maximum power requirement rich mixture provided also has advantage of
Correct : D. all of the above
64. Multi cylinder engines needs air-fuel ratio which is
Correct : C. richer than the single cylinder engines
65. In multi cylinder engines, cylinder close to carburetor receives
Correct : B. leaner mixture
66. In multi cylinder engines,cylinder away from carburetor receives
Correct : A. richer mixture
67. In multi cylinder engines,in all the cylinders I. Air-fuel ratio is same, II.Air-fuel ratio is different
Correct : B. only i is false
68. Transient condition of SI engine is
Correct : C. starting
69. Transient condition of SI engine is I. Starting II. Acceleration III. Idling IV. Deceleration V. Warming up
Correct : B. only i,ii, iv and v
70. Transient conditions in SI engine occurs because of
Correct : D. all of the above
71. Transient conditions in SI engine occurs because of
Correct : C. both a and b
72. Transient conditions in SI engine occurs because of
Correct : B. quantity of fuel in intake manifold may be increasing or decreasing
73. Transient conditions in SI engine occurs because of
Correct : D. all of the above
74. Petrol is mixture of hydrocarbons having
Correct : B. different boiling points
75. Petrol having high vapour pressures and low boiling points are called
Correct : A. light ends
76. Petrol fuel which is more volatile are called
Correct : C. light ends
77. When 10% of fuel is vaporised it is called
Correct : B. 10 per cent point
78. During starting, richer mixture is sent through carburetor because
Correct : C. it provides heavy ends of fuel in cylinder
79. When 100% of fuel is vaporised it is called
Correct : C. end point
80. During cold starting, richer mixture is provided
Correct : A. because lean mixture is created in cylinder because of less vapourized fuel availability in air.
81. During cold starting problems
Correct : A. vaporized fuel in carburetor is condensed in intake manifold, cylinder and piston top
82. During cold starting problems air-fuel mixture sent to engine is
Correct : B. 5 to 10 times normal amount of fuel
83. During cold starting problems air – fuel ratio required is
Correct : C. 3 to 1
84. Petrol engines are
Correct : C. quantity governed
85. Pump which provide additional fuel quantity during acceleration is called as
Correct : D. acceleration pump
86. During acceleraton lean mixture is reached in cylinder because
Correct : D. fuel lags behind in intake manifold as vaporized fuel is passed in the cylinder and more fuel is collected in intake manifold which is not vaporized during subsequent strokes as during normal working conditions of engine
87. Acceleration term refers to
Correct : A. increasing speed of engine
88. Requirements of carburetor are
Correct : D. all of the above
89. Simple carburetor doesn't have which of the following element in its arrangement
Correct : B. auxiliary air port
90. Carburetor depression is a
Correct : C. pressure difference
91. Pressure at throat section of venturi in simple carburetor is
Correct : D. below atmospheric pressure
92. Carburetor depression is pressure difference between
Correct : A. pressure in float chamber and at float section in venturi
93. Simple carburetor can be used for following applications
Correct : B. engine running at constant speed without load varying on engine
94. Jet tube in simple carburetor is also called as
Correct : C. both a and b
95. Nozzle lip is
Correct : D. level difference between level of tip of main jet and level of fuel in float chamber
96. Nozzle lip is provided in simple carburetor
Correct : A. to avoid overflow of liquid fuel from float chamber
97. Minimum cross section in venturi is caleed as
Correct : B. throat
98. Main suction or vacuum is created in simple carburetor at
Correct : C. throat section
99. Fuel quantity in the all the types of carburetors is mainly controlled with the help of which of the following device
Correct : D. throttle valve
100. Which of the following device is directly connected to accelerator in vehicle