100 IC engine and Automobile Technical Questions
1. Which is not the common component between a petrol and diesel engine?
Ans: Ignition Oil
2. Highest useful compression ratio is the compression ratio at which the engine
Ans: Can operate without detonation
3. The purpose of a condenser in the ignition system of petrol engine is to :
Ans: Avoid arcing across the contact breaker points
4. Higher octane rating of a SI engine fuel indicates that the fuel has:
Ans: Longer ignition delay
5. Knocking tendency in a SI engine reduces with increasing:
Ans: Engine speed
6. Reference fuels used for cetane rating of CI engines fuels would include
Ans: Cetane and alpha-methyl naphthalene
7. Octane number of LPG fuel is :
Ans: Higher than iso-octane
8. Accumulation of carbon deposit on combustion chamber of an IC engine leads to increase in :
Ans: Compression ratio
9. In a Diesel cycle, heat rejection takes place at :
Ans: Constant volume
10. A Hook’s joint in a automobile transmission system is preferred when the driving and driven shafts are:
Ans: Non-parallel and intersecting
11. Reboring of an engine cylinder to the next oversize would slightly
Ans: Increase the stroke volume
12. The standard firing order of a six cylinder in line left hand crank shaft is :
13. Cylinder block construction by mono-block is preferred to individual cylinder construction because of?
(a)Compact engine size
(b)Easy manufacturing operations
(c)Better water sealed joints
(d)All of the above
14. A loose fit between a dry cylinder liner and cylinder block would cause:
Ans: High operating temperatures
15. The part of a piston intended to strengthen the position head so as to withstand the force of explosion is :
Ans: Piston web
16. In case of offset pistons, the piston pin hole axis is made offset from the cylinder centerline towards the :
Ans: Major or minor thrust side
17. All of the following are the merits of a side valve(L.head) operating mechanism, except-
(a)High volumetric efficiency
(b)Low engine Height
(c) Low production cost
Ans: High volumetric efficiency
18. Bent of a valve stem can be straightened by :
(a)Valve stem straighter
(b)Valve stem grinder
(c) Dial gauge
(d)None of the above
19. What could be the probable reason of necking of valve stem?
Ans: Leakage of gases at valve seat.
20. Engine lubricating oil pump is usually driven by a?
Ans: Camshaft gear
21. The purpose of a radiator pressure cap is to maintain the working pressure of a water cooling system.
Ans: Higher than the atmospheric pressure
22. Which is not an advantage of multi cylinder air cooled engines when compared to multi cylinder water cooled engines?
Ans: Maintains uniform cooling all around the cylinders
23. The part of an overhead valve mechanism arranged between the valve tappet and rocker arm is :
Ans: Push rod
24. Specific gravity of a lubricating oil can be determined by a?
Ans: Hydro meter
25. A manual method commonly used for measuring the engine lubricating oil level is :
Ans: An oil dipstick
26. Engine lubricating oil pumps are usually positive displacement types because they are suitable for?
Ans: High pressure ratios.
27. In a positive crank case ventilation system , the blow by gases drawn from the crankcase is fed to the :
Ans: Inlet manifold
28. The part of a carburetor where air velocity is the maximum is called?
29. A petrol engine requires a lean air fuel mixture at:
30. Which one of the following carburetors does not contain separate accelerating pump circuit?
(a) Solex Carburetor (b)Zenith Carburetor
(c) Carter Carburetor (d)SU Carburetor
Ans: (d) SU carburetor
31. In carburetors, compensating devices are used to provide?
Ans: Correct proportions of fuel air mixture at all speeds
32. Which is not correct as regards to an open type combustion chamber?
Ans: Smooth running
33. Multi-hole type diesel injectors are generally employed in :
Ans: Open combustion chambers
34. The testing and adjustment of a diesel injection pump for the accuracy of its firing interval is known as :
35. All of the following parameters hamper knocking tendency in a compression ignition engine except:
(a)Early injection fuel (b)Higher compression ratio
(c) High engine load (d) High inlet pressure and temperature
Ans: (a) Early injection fuel
36. In a can type ignition coil, the secondary winding is first wound over:
Ans: A laminated iron core
37. Vacuum advance mechanism for ignition advance in a petrol engine performs effectively at :
Ans: Part throttle opening
38. Insufficient contact breaker gap results in :
Ans: Engine misfiring at high speeds
39. Spark plug gap is generally measured by a :
Ans: Feelex gauge
40. The negative plate of a fully discharged lead acid battery contains:
41. The state of charge of a lead acid battery under actual operating conditions can be tested by :
Ans: A hydrometer
42. Cracked cell covers of a lead acid battery is a symptom of :
Ans: Overcharged battery
43. Output of alternators employed in automobile electrical system is regulated by a :
Ans: voltage regulator
44. In an alternator the electromotive force is induced in the :
Ans: Stator windings
45. D.C.Generators used in automobiles are usually of :
Ans: Self excited type
46. In a d.c,. generator, the effect of the flux produced by the armature current on the main magnetic field flux is called:
Ans: Armature reaction
47. Which is not the common component between a d.c. generator and an alternator?
48. The voltage regulator in the combined voltage and current regulator of a d.c charging circuit contains
Ans: Shunt and series winding
49. An electric motor is a prime mover which converts
Ans: Electrical energy into mechanical energy
50. D.C.series motors are widely employed for starting automobile engines because d.c. series motors have :
Ans: Low speed at high loads
51. Excessive clutch free pedal play would cause:
Ans: Clutch drag
52. A wet clutch is more preferred to a dry clutch:
Ans: When it is decided to achieve longer life
53. In case of a friction clutch, the pressure plate is held against the clutch plate by :
Ans: Thrust springs
54. The term clutch slip as applied to a fluid fly wheel:
Ans: Decrease with the speed of driving shaft
55. A sliding mesh gearbox has a gear ratio 4:1 at the third gear position. The clutch shaft gear has 15 teeth and its mating lay shaft gear is having 45 teeth. If the main shaft gear contains 28 teeth, the mating lay shaft gear should have:
56. Which one of the following is a false statement as regards to a synchromesh gear box ?
(a)The synchronizing unit is locked to the main shaft
(b)Main shaft gears are always free to rotate on the main shaft.
(c) The main shaft gears and the corresponding lay shaft gears are always in constant mesh.
(d)At a particular gear position, power flow takes place from main shaft gear to the synchronizing unit and then to the main shaft.
Ans: (a) The synchronizing unit is locked to the main shaft
57. Which transmission unit is used to turn the driven shaft faster than the driving shaft?
58. The part of a torque converter that facilitates change of torque between input and output shaft is the:
59. The type of gears used for transmitting power between two-non intersecting perpendicular shafts is :
Ans: Hypoid gears
60. The components of an automobile transmission system that facilitate the drive to turn at right angle are:
Ans: Bevel pinion and crown wheel
61. All types of rear live axles have to take:
Ans: Driving torque
62. Which statement is true in the context of a torque tube type rear axle drive?
(a) Side thrust is taken by the torque tube
(b)No universal joint is required
(c) No slip joint is required
(d) No shackle is required
Ans: (c) No slip joint is required
63. Which one of the following is not considered for calculating the unsprung weight?
(a) Steering Knuckle (b)Brakes (c) Axles (d)Chassis frame
Ans: (d) Chassis frame
64. Coil springs used for automobile suspension system can withstand:
Ans: Bending and shear stress
65. In a Mac Pherson strut type of independent suspension , the coil spring is arranged:
Ans: On a strut carrying the shock absorber
66. In a revered elliot type stub axle, the kingpin is locked to the :
Ans: Front axle
67. The steering geometry that aids directional stability is :
Ans: Positive castor
68. Ackerman steering mechanism is popularly employed to steer the front wheels because:
Ans: It is a simple mechanism
69. Which is not the advantage of low aspect ratio tyres:
(a) Comfortable ride
(b)Better load carrying capacity
(c) Less wear
(d) High cornering power
Ans: (a) Comfortable ride
70. Circumferential grooves on automobile tyres:
Ans: Reduce the danger of skidding
71. Compared to cross ply tyre, the radial ply tyre has the disadvantage of :
Ans: Uncomfortable ride at low speeds
72. Tyre rotation is a recommended method to equalize the tyre wear. In doing the tyre rotation, generally, the spare wheel will be fitted to the :
Ans: Rear right side
73. A car which runs along a straight level road at a speed of 36km/hour is brought to rest in 2 seconds by applying the brakes. The stopping distance is :
Ans: 10 meters
74. ‘ By passport ‘ in a master cylinder helps to :
Ans: Convey the excess fluid accumulated in compression chamber to the reservoir after brakes are released.
75. In an air brake system when the brake pedal is freed to deactivate the brakes, the high pressure air form the lines is released to the atmosphere through the :
Ans: Exhaust port in the break valve.
76. Which one of the following is a drawback of disc brakes when compared to drum brakes?
(a) High intensity of pressure on friction pads
(b)Better anti-fade characteristics
(c) Low unsprung weight
(d) Low thermal expansion of friction surfaces
Ans: (a) High intensity of pressure on friction pads
77. The component of an air brake system that actuates the break shoe can is ?
Ans: Break chamber
78. The purpose of circumferential fins constructed on the outer periphery of the break drum is to?
Ans: Lower the break operating temperatures
79. The type of reflector used for automobile head lamp is :
80. An oxidation catalyst that commonly used in catalytic converters is :
81. A three way catalytic converter is used to control the emissions due to :
Ans: Unburned hydro carbons, carbon monoxide and oxides of nitrogen
82. An aerodynamic device mounted at the rear of an automobile to reduce lift at high speeds is :
83. As per the BIS(Bureau of Indian Standards)2000 specifications, the permissible amount of sulphur content in gasoline is limited to :
84. As per the motor vehicle act 1988, the maximum speed limit for motor cycle is :
85. As per the section IV of Motor vehicle act 1988, the minimum age limit for obtaining a driving license to drive a transport vehicle is :
86. An automobile engine is an example of :
Ans: Open system
87. The maximum possible thermal efficiency of a heat engine is limited by?
Ans: Second law of thermodynamics
88. Which one of the following is not a thermodynamic property?
(a)Entropy (b)Pressure (c) Volume (d) Heat
89. A high viscosity index of lubricating oil indicates:
Ans: Relatively little change of viscosity with change of temperature
90. Bharath stage III would come into force Nationwide from :
Ans: 1 April, 2010
91. India started to adopt European emission norms in the year:
92. The principal use of an engine dynamometer is to measure:
Ans: Torque developed by the engine
93. Which among the following is not a merit of front engine with front wheel drive vehicles
(a) Better tractive effort when going uphill
(b)Better road adhesion
(c) Improved riding performance
(d)Less tendency to skidding
Ans: (a) Better tractive effort when going uphill
94. Engine placed at the rear with rear axles as live axles:
Ans: Ensure lower overall height
95. The most attractive feature of engines made of Aluminium alloys is :
Ans: Low weight to power ratio
96. A ring spanner is usually manufactured by ?
Ans: Drop forging
97. Piston compression rings are made of :
Ans: Alloy cast iron
98. Which among the following is a surface finishing operation?
(a)surface grinding (b)Centerless grinding
(c) Buffing (d)Honing
Ans: (d) Honing
99. Stroke of I.C.engine equals:
Ans: Twice the crank radius
100. Vehicle weight when it is not loaded with passengers and cargo, but inclusive of the weight of full tank is known as :
Ans: Curb weight