PSC Junior Instructor mechanic Motor Vehicle Model Questions and Answers

76. The shock absorber dissolve can be reduced by pressurizing the fluid with …………… gas.
(A) Hydrogen
(B) Nitrogen
(C) Oxygen
(D) Carbon dioxide
Answer: B

77. In the code 145 SR-13 of a radial tire, 13 denominate
(A) Tire width
(B) Aspect ratio
(C) Inner diameter of tire
(D) Load carrying capacity
Answer: C

78. Which light provide a better night time visibility?
(A) Halogen
(B) LED
(C) Both (A) and (B)
(D) Xenon
Answer: D

79. The magnitude of slip angle is small at
(A) Low speed
(B) Medium speed
(C) High speed
(D) Very high speed
Answer: A

80. In SI engine, which one of the following combustion chamber have centrally located spark plug?
(A) Flat head
(B) Hemispherical
(C) Wedge type
(D) Inverted bath tub
Answer: B

81. To improve the resistance to wear and corrosion, cylinder liners are plated with
(A) Platinum
(B) Vanadium
(C) Zinc
(D) Chromium
Answer: D

82. Which one of the following is not an advantage of toothed belt drive?
(A) Silent drive
(B) Lowest cost
(C) Long life
(D) No need of lubrication
Answer: C

83. Tendency of fuel to change from liquid to vapour form is called
(A) Pour point
(B) Volatility
(C) Viscosity
(D) Flash point
Answer: B

84. Cold plugs are generally used in
(A) High speed heavy duty engines
(B) Low speed heavy duty engines
(C) Low speed medium duty engines
(D) Both (B) and (C)
Answer: A

85. Which one of the given carburetor is a constant vacuum type?
(A) Carter carburetor
(B) S.U. carburetor
(C) Zenith carburetor
(D) Solex carburetor
Answer: B

86. What are the advantages of dual mass fly wheel over a single fly wheel?
(A) Less synchronization wear
(B) Gear shifting easy
(C) Reducing neutral gear rattle
(D) All of these
Answer: D

87. More injection delay period will lead to
(A) Diesel knock
(B) Detonation
(C) Both (A) and (B)
(D) Controlled combustion
Answer: A

88. Which one of the following is not a part of cover assembly in a clutch?
(A) Pressure plate
(B) Release lever
(C) Release bearing
(D) Springs
Answer: C

89. Free wheel unit in the transmission are provided with dog clutch to
(A) Lock free wheel
(B) Engage free wheel
(C) Disengage free wheel
(D) None of these
Answer: A

90. Critical whirling speed of a propeller shaft can be increased by
(A) Decreasing diameter
(B) Increasing length
(C) Both (A) and (B)
(D) Decreasing length
Answer: D

91. Which member of a torque converter is also known as reactor?
(A) Lock up clutch
(B) Stator
(C) Impeller
(D) Turbine
Answer: B

92. Front wheel drive cars are usually employed with ……………. type independent suspension to provide maximum room in the engine compartment.
(A) Vertical guide
(B) Trailing link
(C) Mac Pherson strut
(D) Wish bone
Answer: C

93. The effect of positive scrub radius on the road wheels are
(A) Toe-in
(B) Toe-out
(C) Pull to one side
(D) Wobble
Answer: B

94. Glow plugs are fitted an engine with
(A) Pre combustion chamber
(B) Turbulent chamber
(C) Both (A) and (B)
(D) Open combustion chamber
Answer: A

95. The main disadvantage of lower aspect ratio
(A) More tire wear
(B) Less cornering power
(C) High speed shimmy
(D) Uncomfortable ride
Answer: D

96. Contact breaker point of a 6 cylinder 4 stroke engine operating at 3000 RPM will make and break for …………….. times in a minute.
(A) 3000
(B) 6000
(C) 9000
(D) 12000
Answer: C

97. One bar is equal to
(A) 10 Kpa
(B) 100 Kpa
(C) 1000 Kpa
(D) 10000 Kpa
Answer: B

98. Piston rings and cylinder liners are
(A) Die casted
(B) Hollow casted
(C) Sand casted
(D) Centrifugal casted
Answer: D

99. Gear mechanism in a slack adjuster
(A) Worm and wheel
(B) Worm and nut
(C) Worm and roller
(D) Rack and pinion
Answer: A

100. The types of lubrication in which scavenging pump required
(A) Splash system
(B) Pressure system
(C) Dry sump system
(D) Petrol system
Answer: C