MCQOPTIONS
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MCQOPTIONS
This section includes 538 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The advantage of the fuel injection system over the carburetor system is |
| A. | improved fuel efficiency |
| B. | improved emission |
| C. | improved power output |
| D. | all of these |
| Answer» E. | |
| 52. |
The PCV valve incorporates a spring loaded plunger and opens in proportion to the level of vacuum pressure in the intake manifold. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 53. |
In a four cylinder in-line engine, the number of firing strokes in one revolution of the crank is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 54. |
In a four speed four-stroke Diesel engine, the intake valve |
| A. | opens at T.D.C. and closes at B.D.C. |
| B. | opens at 20° before T.D.C. and closes at 35° after B.D.C. |
| C. | opens at 10° after T.D.C. and closes at 20° before B.D.C. |
| D. | none of the above |
| Answer» C. opens at 10° after T.D.C. and closes at 20° before B.D.C. | |
| 55. |
The motion of the cam is transferred to the rocker arm, moving it upwards and downwards. This rocker-arm motion then forces the valve downwards against the force in the valve spring so that the valve can open. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 56. |
The camshaft is driven by the crankshaft via the timing belt. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 57. |
The octane rating of petrol commerically available is |
| A. | 85-95 |
| B. | 95-100 |
| C. | 100-110 |
| D. | 110-125 |
| Answer» B. 95-100 | |
| 58. |
When the piston is at T.D.C, the volume above the piston in the combustion chamber is the |
| A. | clearance volume |
| B. | cylinder volume |
| C. | exhaust volume |
| D. | none of these |
| Answer» B. cylinder volume | |
| 59. |
A petrol that detonates easily is called |
| A. | high octane petrol |
| B. | low octane petrol |
| C. | unleaded petrol |
| D. | blended fuel |
| Answer» C. unleaded petrol | |
| 60. |
The ease with which petrol vapourizes is called its |
| A. | oxidation |
| B. | octane number |
| C. | volatility |
| D. | cetane number |
| Answer» D. cetane number | |
| 61. |
In Diesel engines, during suction stroke, __________ is drawn in the cylinder. |
| A. | air and fuel |
| B. | only fuel |
| C. | only air |
| D. | none of these |
| Answer» D. none of these | |
| 62. |
The sequence order of events in a four-stroke engine is |
| A. | suction - exhaust - power - compression |
| B. | suction - power - compression - exhaust |
| C. | suction - compression - power - exhaust |
| D. | exhaust - compression - power - suction |
| Answer» D. exhaust - compression - power - suction | |
| 63. |
In petrol engines, during suction stroke, __________ is drawn in the cylinder |
| A. | air and fuel |
| B. | only fuel |
| C. | only air |
| D. | none of these |
| Answer» B. only fuel | |
| 64. |
The crankshaft of a typical in-line four cylinder engine has __________ balance weights. |
| A. | 12 |
| B. | 4 |
| C. | 16 |
| D. | 8 |
| Answer» E. | |
| 65. |
The connecting rods are generally made of __________ shaped cross-section. |
| A. | I |
| B. | C |
| C. | L |
| D. | H |
| Answer» B. C | |
| 66. |
The connecting rod lower end is connected to the relevant __________ of crankshaft. |
| A. | big end |
| B. | crank arm |
| C. | journal |
| D. | small end |
| Answer» D. small end | |
| 67. |
The crescent-shaped cavity on the piston head top surface is called as |
| A. | piston oil hole |
| B. | snap ring |
| C. | valve recess |
| D. | valve clearance |
| Answer» D. valve clearance | |
| 68. |
The function of oil-control rings is that it |
| A. | lubricates the cylinder wall by releasing oil from its hole |
| B. | keeps the cylinder wall lubricated by holding oil in its channel |
| C. | prevents engine oil from going into the combustion chamber and returns excess lubricating oil off the cylinder wall through the return holes in the piston to the oil pan |
| D. | maintains a seal and prevents escape of burned gases and oil leakage |
| Answer» D. maintains a seal and prevents escape of burned gases and oil leakage | |
| 69. |
The reconditioning process used to give cylinder bore surfaces a cross-hatch pattern, is known as |
| A. | honing |
| B. | porous plating |
| C. | boring |
| D. | shot peening |
| Answer» B. porous plating | |
| 70. |
The main merit of a multi-cylinder type cylinder sleeve is |
| A. | smaller engine dimensions |
| B. | better cooling efficiency |
| C. | high rigidity |
| D. | none of these |
| Answer» B. better cooling efficiency | |
| 71. |
An engine has a clearance volume of 100 cm3 and a swept volume of 800 cm3. The compression ratio is |
| A. | 7:1 |
| B. | 8:1 |
| C. | 9:1 |
| D. | 10:1 |
| Answer» D. 10:1 | |
| 72. |
A four-cylinder engine has a capacity of 2.4 litres. The swept volume of one cylinder is |
| A. | 400 cm3 |
| B. | 600 cm3 |
| C. | 1200 cm3 |
| D. | 2400 cm3 |
| Answer» C. 1200 cm3 | |
| 73. |
The compression ratio in Diesel engines is less than the petrol engine. |
| A. | Agree |
| B. | Disagree |
| Answer» C. | |
| 74. |
The air resistance to a car at 20 kmph is R. The air resistance at 40 kmph will be |
| A. | R |
| B. | 2 R |
| C. | 4R |
| D. | 4 R2 |
| Answer» D. 4 R2 | |
| 75. |
A petrol engine of a car develops 125 N-m torque at 2700 r.p.m. The car is driven in second gear having gear ratio of 1.75. The final drive ratio is 4.11. If the overall transmission efficiency is 90%, then the torque available at the driving wheels is |
| A. | 8.091 N-m |
| B. | 80.91 N-m |
| C. | 809.1 N-m |
| D. | 8091 N-m |
| Answer» D. 8091 N-m | |
| 76. |
The engine torque increases with the increase in engine speed up to a certain point after which it starts to fall down. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 77. |
In comparison to frame type construction, the frameless structure construction of automobiles is economical when produced in __________ numbers. |
| A. | small |
| B. | large |
| Answer» C. | |
| 78. |
Which of the following is not an automobile ? |
| A. | Motor cycle |
| B. | Passenger car |
| C. | Aeroplane |
| D. | Truck |
| Answer» D. Truck | |
| 79. |
The positive plates of a lead acid battery has |
| A. | ead peroxide (PbO₂) |
| B. | pongy lead (Pb) |
| C. | ead sulphate (PbSO₄) |
| D. | ulphuric acid (H₂SO₄) |
| Answer» B. pongy lead (Pb) | |
| 80. |
The negative plates of a lead acid battery has |
| A. | ead peroxide (PbO₂) |
| B. | pongy lead (Pb) |
| C. | ead sulphate (PbSO₄) |
| D. | ulphuric acid (H₂SO₄) |
| Answer» C. ead sulphate (PbSO₄) | |
| 81. |
Wheel base of a vehicle is the |
| A. | istance between the centres of the front and rear wheels |
| B. | istance between the centres of the front tyres |
| C. | istance between the centres of the rear tyres |
| D. | xtreme length of the vehicle |
| Answer» B. istance between the centres of the front tyres | |
| 82. |
The engine oil viscosity is defined by ___________ ratings. |
| A. | utomatic transmission fluid (ATF) |
| B. | ociety of automotive engineers (SAE) |
| C. | ross vehicle weight (GVW) |
| D. | merican petroleum institute (API) |
| Answer» C. ross vehicle weight (GVW) | |
| 83. |
In order to implement gear changes in the gear unit of an automatic transmission, a ___________ is used. |
| A. | ynchronizer |
| B. | lanetary gear |
| C. | agnetic clutch |
| D. | ydraulic multi plate clutch |
| Answer» E. | |
| 84. |
A heat treated glass generally used in automobiles bursts into ________ upon cracking, |
| A. | harp edged fragments |
| B. | mall particles |
| C. | arge particles |
| D. | one of these |
| Answer» C. arge particles | |
| 85. |
The octane rating of petrol commercially available is |
| A. | 5-95 |
| B. | 5-100 |
| C. | 00-110 |
| D. | 10-125 |
| Answer» B. 5-100 | |
| 86. |
Which of the following symptom is caused as a result of brake disc run out? |
| A. | neffectiveness of the brakes |
| B. | udder during braking |
| C. | ocalized wearing of the brake pads |
| D. | apid wearing of the brake pads |
| Answer» C. ocalized wearing of the brake pads | |
| 87. |
An under-inflated tyre will wear the tread most |
| A. | ear the centre |
| B. | ear the edges |
| C. | n the lateral direction |
| D. | n the cross direction |
| Answer» C. n the lateral direction | |
| 88. |
The purpose of a balancer shaft is to |
| A. | alance the timing in the movement of the two groups of pistons |
| B. | ncrease inertia force of the rotating crankshaft |
| C. | educe vibrations caused by the crankshaft rotation |
| D. | djusts the timing of the intake and exhaust valve openings |
| Answer» D. djusts the timing of the intake and exhaust valve openings | |
| 89. |
The correct way to rectify an imbalanced wheel is to |
| A. | djust the tyre pressure |
| B. | otate the tyres |
| C. | djust the damper spring tension |
| D. | ttach appropriate weights to the wheel at appropriate positions |
| Answer» E. | |
| 90. |
A maintenance free battery |
| A. | as lead-antimony plate grid |
| B. | as lead-calcium plate grid |
| C. | oes not contain acid |
| D. | oes not contain water |
| Answer» C. oes not contain acid | |
| 91. |
A laminated glass upon cracking |
| A. | ursts into sharp edged fragments |
| B. | ursts into granular pieces |
| C. | andwiched layer traps the fragments |
| D. | reaks into the form of crystals |
| Answer» D. reaks into the form of crystals | |
| 92. |
The self ignition temperature of Diesel as compared to petrol is |
| A. | igher |
| B. | ower |
| C. | ame |
| D. | epends on fuel quality |
| Answer» C. ame | |
| 93. |
The Diesel engines are also known as |
| A. | park ignition (S.I.) engines |
| B. | ompression ignition (C.I.) engines |
| C. | team engines |
| D. | one of these |
| Answer» C. team engines | |
| 94. |
The basic purpose of tyre rotation on automobiles is to |
| A. | void ply separation |
| B. | qualize wear |
| C. | et better ride |
| D. | one of these |
| Answer» C. et better ride | |
| 95. |
The function of a governor in automobiles is to |
| A. | imit the power |
| B. | imit the vehicle speed |
| C. | aintain constant engine speed |
| D. | aximise the fuel economy |
| Answer» C. aintain constant engine speed | |
| 96. |
The main task of a battery in automobiles is to |
| A. | upply electricity to the alternator |
| B. | ct as a reservoir or stabilizer of electricity |
| C. | upply electricity to the vehicle's electrical system at all times while the engine is running |
| D. | upply a large amount of power to turn the starter motor when the engine is being started |
| Answer» E. | |
| 97. |
The basic part of the engine, to which the other engine parts are attached or assembled is the |
| A. | ylinder head |
| B. | rankshaft |
| C. | ylinder block |
| D. | il pan |
| Answer» D. il pan | |
| 98. |
The seat belt tensioners are built in the |
| A. | ront seats |
| B. | houlder anchors |
| C. | eat belt retractors |
| D. | eat belt buckles |
| Answer» D. eat belt buckles | |
| 99. |
The path taken by intake air is |
| A. | arburettor (or throttle body) air cleaner intake manifold intake ports cylinders |
| B. | ir cleaner carburettor (or throttle body) intake ports intake manifold cylinders |
| C. | ir cleaner intake manifold carburettor (or throttle body) intake ports cylinders |
| D. | ir cleaner carburettor (or throttle body) intake manifold intake ports cylinders |
| Answer» E. | |
| 100. |
The power source for a brake booster is |
| A. | xhaust manifold pressure |
| B. | lectricity |
| C. | he pressure difference between the atmospheric pressure and the vacuum pressure in the intake manifold |
| D. | ydraulic pump |
| Answer» D. ydraulic pump | |