MCQOPTIONS
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MCQOPTIONS
This section includes 471 Mcqs, each offering curated multiple-choice questions to sharpen your Uncategorized topics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Economiser system comes into action during |
| A. | cruising |
| B. | idling |
| C. | starting |
| D. | full throttle condition |
| Answer» E. | |
| 52. |
Temperature Coeficient of the fuel is |
| A. | relation between temperature ,the rate of acceleration of oxidation or burning and pressure |
| B. | relation between temperature and the rate of acceleration of oxidation or burning. |
| C. | relation between temperature and the rate of acceleration of oxidation or burning. |
| D. | relation between temperature and pressure. |
| Answer» C. relation between temperature and the rate of acceleration of oxidation or burning. | |
| 53. |
SI engine is also called as |
| A. | auto ignition engine |
| B. | compression ignition engine |
| C. | otto engine |
| D. | diesel engine |
| Answer» D. diesel engine | |
| 54. |
Drawbacks of simple carborator are |
| A. | it provides richest mixture when speed engine is high. |
| B. | it provides leanest mixture when speed engine is less. |
| C. | both a&b |
| D. | none of the above. |
| Answer» D. none of the above. | |
| 55. |
SI engines use mixtures having AF ratio between |
| A. | 4:1 to 24:1 |
| B. | 3:1 to 17:1 |
| C. | 15:1 to 80:1 |
| D. | 1:1 to 5:1 |
| Answer» C. 15:1 to 80:1 | |
| 56. |
For producing maximum power excess fuel burning leads to |
| A. | incomplete combustion |
| B. | more co is formed |
| C. | more co2 is formed |
| D. | both a and b |
| Answer» E. | |
| 57. |
Carburator is used to |
| A. | meter air-fuel quantity |
| B. | increase air-fuel quantity |
| C. | decrease air-fuel quantity |
| D. | mix air-fuel. |
| Answer» B. increase air-fuel quantity | |
| 58. |
When 10% of fuel is vaporised it is called |
| A. | 90 per cent point |
| B. | 10 per cent point |
| C. | any point |
| D. | 110 per cent point |
| Answer» C. any point | |
| 59. |
Acceleration term refers to |
| A. | increasing speed of engine |
| B. | increasing speed of throttle valve opening or closing |
| C. | increasing speed of choke valve opening or closing |
| D. | increasing speed of fuel flow |
| Answer» B. increasing speed of throttle valve opening or closing | |
| 60. |
When 100% of fuel is vaporised it is called |
| A. | 100 per cent point |
| B. | 10 per cent point |
| C. | end point |
| D. | 110 per cent point |
| Answer» D. 110 per cent point | |
| 61. |
Which of the following device is directly connected to accelerator in vehicle |
| A. | throttle valve |
| B. | throat |
| C. | needle valve |
| D. | choke valve |
| Answer» B. throat | |
| 62. |
Addition of ethyl bromide in TEL helps in |
| A. | improving anti knock characteristics |
| B. | reducing anti knock characteristics |
| C. | prevents lead deposits |
| D. | none of the above |
| Answer» D. none of the above | |
| 63. |
The preparation phase in SI engine will take about |
| A. | 20 deg. of crank angle |
| B. | 40 deg of crank angle |
| C. | 30 deg. of crank angle |
| D. | 10 deg. of crank angle |
| Answer» B. 40 deg of crank angle | |
| 64. |
The essential conditions for combution arei) The presence of combustible mixtureii) Initiation by any means like spark plug is not requirediii) Stabilization and propagation of flame in the combution chamberOut of these following is correct |
| A. | all correct |
| B. | i and iii |
| C. | ii and iii |
| D. | i and ii |
| Answer» C. ii and iii | |
| 65. |
In the rich mixtures used for automobile applications |
| A. | fuel quantity is more than stoichiometric quantity |
| B. | air quantity is more than stoichiometric quantity |
| C. | both the quantities are same |
| D. | fuel quantity is more than the air quantity |
| Answer» B. air quantity is more than stoichiometric quantity | |
| 66. |
In the Lean mixtures used for automobile applications .. |
| A. | fuel quantity is more than stoichiometric quantity |
| B. | air quantity is more than stoichiometric quantity |
| C. | both quantities are same |
| D. | fuel quantity is more than the air quantity |
| Answer» C. both quantities are same | |
| 67. |
Practical limits of fuel air ratio for combution in SI engines is .. |
| A. | 0.11 to 0.05 |
| B. | 0.2 to 0.1 |
| C. | 0.05 to 0.033 |
| D. | 0.2 to 0.033 |
| Answer» B. 0.2 to 0.1 | |
| 68. |
Practical limits for air fuel ratio in SI engines provides .. |
| A. | range of air fuel ratio which gives comfortable working of si engine |
| B. | range of air fuel ratio to get combustion close to stoichiometric conditions in si engine |
| C. | range of air fuel ratio for obtaining maximum power in si engine |
| D. | all of the above |
| Answer» C. range of air fuel ratio for obtaining maximum power in si engine | |
| 69. |
Stoichiometric air fuel ratio suggests .. |
| A. | correct quantity of fuel-air ratio which gives more economy |
| B. | correct quantity of fuel-air ratio which gives more power |
| C. | correct quantity of fuel-air ratio which gives complete combution |
| D. | all of the above |
| Answer» D. all of the above | |
| 70. |
Maximum pressure obtained in normal SI engine during motoring is about .. |
| A. | 2 bar |
| B. | 15 bar |
| C. | 8 bar |
| D. | 40 bar |
| Answer» D. 40 bar | |
| 71. |
Ignition limits in the SI engine depends upon . |
| A. | mixture ratio and temperature |
| B. | volumetric efficiency and temperature |
| C. | engine size and volumetric efficiency |
| D. | mixture ratio and engine size |
| Answer» B. volumetric efficiency and temperature | |
| 72. |
Pressure during motoring in SI engine compared to CI engine is . |
| A. | less |
| B. | more |
| C. | same |
| D. | none of the above |
| Answer» B. more | |
| 73. |
Volatility property of the fluid helps in |
| A. | increasing vaporization of fuel |
| B. | decreasing vaporization of fuel |
| C. | can increase or decrease vaporization |
| D. | none of the above |
| Answer» D. none of the above | |
| 74. |
For high speed S I engines following things occurs |
| A. | less time available for mixture preparation |
| B. | more time available for mixture preparation |
| C. | it varies with fuel properties |
| D. | all of the above |
| Answer» B. more time available for mixture preparation | |
| 75. |
Maximum pressure in SI engine is about .. |
| A. | 10 bar |
| B. | 70 bar |
| C. | 50 bar |
| D. | 30 bar |
| Answer» E. | |
| 76. |
Approximate temperature produced by spark plug is .. |
| A. | 5,000 deg.celsius |
| B. | 20,000 deg.celsius |
| C. | 2,000 deg.celsius |
| D. | 10,000 deg.celsius |
| Answer» E. | |
| 77. |
The peak pressure in SI engine will be observed when crank position is . |
| A. | about 10 deg. before tdc |
| B. | about 10 deg. after tdc |
| C. | at tdc |
| D. | at bdc |
| Answer» C. at tdc | |
| 78. |
The preparation phase in SI engine will last for about .. |
| A. | 20 deg. of crank rotation |
| B. | 40 deg. of crank rotation |
| C. | 30 deg. of crank rotation |
| D. | 10 deg. of crank rotation |
| Answer» B. 40 deg. of crank rotation | |
| 79. |
The peak temperature in SI engine will be observed when crank position is . |
| A. | about 10 deg. before tdc |
| B. | about 10 deg. after tdc |
| C. | at tdc |
| D. | at bdc |
| Answer» C. at tdc | |
| 80. |
On P. . Diagram, first measurable rise of pressure in SI engine takes place approximately . |
| A. | when crank angle is about 10 deg. before tdc |
| B. | when crank angle is about 10 deg. after tdc |
| C. | when crank angle is about 10 deg. before bdc |
| D. | when crank angle is about 10 deg. after bdc |
| Answer» C. when crank angle is about 10 deg. before bdc | |
| 81. |
Gap size in spark plug electrodes in about . |
| A. | 10 to 20 mm |
| B. | 1 to 2 mm |
| C. | 0.01 mm to 0.1 mm |
| D. | none of the above |
| Answer» C. 0.01 mm to 0.1 mm | |
| 82. |
On P. . Diagram, start of second phase in the combustion of SI engine is indicated by . |
| A. | separation of velocity line from compression line |
| B. | constant pressure |
| C. | fall of pressure |
| D. | separation of combustion curve from motoring curve |
| Answer» E. | |
| 83. |
During propagation of flame in SI engine crank rotates by about . |
| A. | 20 deg. |
| B. | 40 deg. |
| C. | 30 deg. |
| D. | 10 deg. |
| Answer» B. 40 deg. | |
| 84. |
As compared to level of fuel in float chamber, the carburettor nozzle opening is at level |
| A. | same |
| B. | higher |
| C. | lower |
| D. | fluctuating |
| Answer» C. lower | |
| 85. |
SI engines in which diesel is used as a fuel will |
| A. | not run at all |
| B. | run with detonation |
| C. | run normally |
| D. | run with less efficiency |
| Answer» B. run with detonation | |
| 86. |
Which phase of combustion takes place during expansion stroke .. |
| A. | ignition lag |
| B. | preparation phase |
| C. | propagation of flame |
| D. | after burning |
| Answer» E. | |
| 87. |
On P. . Diagram, separation of combustion curve from motoring curve in SI engine takes place |
| A. | when crank angle is about 10 deg. before tdc |
| B. | when crank angle is about 10 deg. after tdc |
| C. | when crank angle is about 10 deg. before bdc |
| D. | when crank angle is about 10 deg. after bdc |
| Answer» B. when crank angle is about 10 deg. after tdc | |
| 88. |
If diesel is used in SI engine, it will not run. What is the correct reason? |
| A. | low compression ratio |
| B. | more density |
| C. | less volatility |
| D. | low burning point |
| Answer» D. low burning point | |
| 89. |
Performance number of SI engine fuel |
| A. | corresponds to octane rating |
| B. | relates to the fuels having octane number more than 100 |
| C. | either a or b |
| D. | none of the above |
| Answer» C. either a or b | |
| 90. |
a blower/compressor driven by engine shaft to increase charge density is called |
| A. | supercharger |
| B. | turbocharger |
| C. | both a & b |
| D. | none of the above |
| Answer» E. | |
| 91. |
The time interval between formation of spark and appreciable pressure rise is |
| A. | spark advance |
| B. | ignition lag |
| C. | propogation lag |
| D. | burning lag |
| Answer» C. propogation lag | |
| 92. |
Detonation tendency is maximum for air:fuel ratio___ |
| A. | 8:1 to 10:1 |
| B. | 10:1 to 12:1 |
| C. | 12:1 to 14;1 |
| D. | 16:1 to 18:1 |
| Answer» D. 16:1 to 18:1 | |
| 93. |
an exhaust gas driven blower/ compressor to increase charge density is called |
| A. | supercharger |
| B. | turbocharger |
| C. | both a & b |
| D. | none of the above |
| Answer» E. | |
| 94. |
First measurable rise of pressure in SI engine takes place approximately |
| A. | when crank angle is about 10 deg. after tdc |
| B. | when crank angle is about 10 deg. before tdc |
| C. | when crank angle is about 10 deg. before bdc |
| D. | when crank angle is about 10 deg. after bdc |
| Answer» C. when crank angle is about 10 deg. before bdc | |
| 95. |
power out put of an engine compared to turbocharge is |
| A. | more |
| B. | same |
| C. | less |
| D. | can not say |
| Answer» D. can not say | |
| 96. |
which is not a supercharger |
| A. | centrifugal compressor |
| B. | root blower |
| C. | vane blower |
| D. | pump |
| Answer» E. | |
| 97. |
compressed air of turbochar is cooled in aftercooler before supply to engine because it |
| A. | reduceses density of air |
| B. | increases volumetric efficiency |
| C. | increases density of air |
| D. | both b and c |
| Answer» E. | |
| 98. |
efficiency of turbocharged engine compared to naturally aspirated engine is |
| A. | more |
| B. | same |
| C. | less |
| D. | can not predict |
| Answer» E. | |
| 99. |
a free piston engine has |
| A. | gear driven supercharger |
| B. | a turbocharger |
| C. | coupled engine, compressor and turbine supercharge |
| D. | gear driven supercharger and separate power turbine |
| Answer» E. | |
| 100. |
A petrol engine is ____________ |
| A. | quality governed |
| B. | quantity governed |
| C. | both a and b |
| D. | none of the above |
| Answer» C. both a and b | |