Jan2018 MECHANIC MOTOR VEHICLE THEORY SENIESTER -IV

  Jan2018 MECHANIC MOTOR VEHICLE  THEORY SENIESTER -IV


l. The thermodynarnic cycle on which the petrol engine works, is
a. Joule cycle b. Otto cycle
c. Rankine cycle d. Stirling cycle
2. In four strokes spark ignition engine, at the end of compression stroke, before the spark occurs, what is the pressure developed inside the combustion chamber?
a. 2 to 4 Kg/cm2 b. 6 to 8 Kg/cm2
c. 10 to 12 Kg /cm2 d. 14 to 16 Kg /cm2
3. In a four stroke petrol engine, during suction stroke --
a. Only air is sucked in b. Only petrol is sucked in
c. Mixture of petrol and air is sucked in d. None of these
4. The sequence of 4 stroke cycle operaåon of S.I. engine is —
a. Induction — power — compression — Exhaust
b. Induction Compression — Power— Exhaust
c. Compression — Induction — Power — Exhaust
d. Compression — Power — Induction - Exhaust
5. In a two s&oke cycle engine, the four process in a cycle namely suction, compression, power (expansion) and exhaust are completed in revolutions of crank shaft.
a. One b. Two
c. Three d. Four
6. In a single cylinder 4 — stroke S.I engine the power s&oke starts after of crank

  a. 900 b. 1800 c, 2700 d. 3600
7. Compression Ratio (CR) of Sel engine is less than C.I. engine because —
a. It makes the engine lighter
 b. Less C.R. gives better performance
c. It is a common practice

d. Higher or equal CR is not possible due to the problem of pre-ignition
8. T — slot provided in the piston —
a. To accommodate the expansion of piston when heated up
b. For the passage of lubricafrlg oil
c. For cooling purpose
d. To reduce the weight of piston
Contd„2i-
9. The part of crank shaft to which connecting rod is connected is called —
 a. Big end b. Crank pin
c. Crank web d. Small end
10. The pefrol engine gets very rich mixture at the time of -
a. Starting b. Idling
c. Accelerating d. Operating at cruising speed
11. Iso — octane content in the fuel of S.L engine —
 a. Retards auto — ignition b. Accelerates auto — ignition

c. Does not affect auto — ignition d. None of these
12. The volumetric efficiency of a good designed engine may be
a. 30 to be 40 to
c. 60 to d. 75 to
13. The venturi in a carburetor causes —
 a. Increase of air velocity b. Decrease of air velocity
c. Decrease of fuel flow d. Decrease of manifold vacuum
14. The main disadvantage of the mechanical fuel pump is that —
a. They need to be located near the engine
b. They are prone to vapour lock

c. They operate only after the engine has started
d. All of the above
15. The throttle valve confrols the supply of -
a. Air only b. Fuel only
c. Air fuel mixture d. None of these
 16. The main advantage of electronic fuel injection (EFI) system is

a. High quality fuel distribution
b. Less fuel consumption
c. Rapid response of the engine to throttle control
 d. All ofthe above
17. Which of the following component, in EFI system, decides the amount of fuel to be injected on the basis of signals received from the wide range of sensors?
a. ECU b. Carburettor
c. Throttle d. Governor
18. In EFI system the engine temperature sensor senses the temperature of —
a. Cooling water at out let b. Cooling water at inlet
c. Suction air d. Exhaust gas
Contd...3/

19. In EFI system the inlet Manifold Pressure Sensor senses the —
 a. Quantity of Air in the inlet manifold
b. Vacuum in the inlet manifold
c. Quantity of fuel supplied in the inlet manifold
 d. Any one of the above
 20. In EFI system the exhaust gas sensor senses the percentage in exhaust gas for calculating air-fuel ratio.
a. NOx b. CO c. 02 d. HC
21. The rate of flow of electrons in a conductor is known as —
a. Current b. Voltage
  c. Resistance d. None of these
  22. A is an electrical one way check valve that will allow current to flow in one direction   only.
a. Diode b. Transistor

c. Capacitor d. Resistor
23. "Whenever a conductor cuts magnetic flux, an e.m.f. is induced in that conductor." This statement is called as
a. Ohm's law  b. Fleming's rule
  c. Faraday' s First law of electromagnetic induction
d. Faraday's second law of elecfromagnetic induction
24. The Large gap in the spark plug may cause the engine —
a. Misfiring b. Over heating
c. Back firing d. Timing disturbance
25. The main function of the condenser in an ignition system is —
a. Minimizing Pitting of the contact breaker points
b. To intensify the spark
c. To absorb the energy stored in the primary winding
d. All ofthe above
a. Short b. Thin  
c. Long d. Thick
26. In general, the hot plugs haveinsulator nose.
27. The vacuum advance mechanism functions at —
a. Light engine load b. Heavy eng;ine load
c. High engine speed d. None ofth.ese

Contd... 4/-
28. The function of a charging system in an automobile is to
a. Supply elecfric power
b. Convert mechanical energy into electrical energy
c. Continually recharge the battery
d. Partly convert engine power into electric power
29. 'lhe number of diodes used in alternator for rectification from AC to DC is / are —
30. The charging voltage at the start of the engine is than when the engine is running on load.
a. Higher b. Lower
c. Equal d. Any one of these
31. The high resistance in an alternator output circuit is often caused by —

a. A bad regulator b. A shorted diode
c. Loose or corroded connection d. None of these
32. The ratio between the number of teeth on the starter motor pinion gear and the engine fly wheel ri.ng gear is about
c. 1 : 15 d. I : 100

33. The magnetic field required for starting motor operation is provided by the — a, Armature b. Field windings
c. Solenoid d. None of these
34. If starter motor spins but does not engage flywheel teeth and does not start the engine, the  problem is most likely caused by a bad
a. Magnetic switch b. Over running clutch

c. Positive battery cable d. Ignition switch
35. The colour of tail light in a car is —
a. White b. Amber
c. Green d. Red
36. The typc of reflector used for automobile head lamp is —
 a. Parabolic b. Hyperbolic
c. Spherical d. Circular
37* The stop lights are also known as —
a. Tail lights b. Brake lights
c. Indicator light d. Fog light
38. The frequency of flashing light per minute in a turn indicator is about —
b. 80
c. 800 d. None of these
  Contd.. S/-

18/MC/S4/4/E
39. In a horn assembly which of the following part vibrates around 2000 vibrations per second?
a. Diaphragm b. Tone disc co Armature d. Contact points
40. A 12 volts windshield wiper motor consumes about ampere of current under normal operation.
c. 10- 15 d. 20 - 30
41. The purpose of air conditioning a car is to confrol —
a. Temperature and pressure b. Pressure and humidity
c. Humidity and temperature d. Temperature, pressure and humidity
42. Which of the following should be cold during normal operation of the air conditioning  system?
a. Compressor b. Condenser
c. Receiver and drier d. Evaporator

43. Which refrigerant is commonly used in modern automobile air-conditioning system?

a. R- 12 b. R- 22
c. R- 134a d. R- 134
44. The purpose of corrugated fins used in condenser and evaporator is to
a. Trap insects and foreign objects, thus preventing them from entering the engine compattment
 b. Control the air flow which passes through the condenser or evaporator
 c. Increase the surface area, thus increasing heat exchange performance
 d. Reinforce the heat exchanger
45. Which of the following sensor data will the automatic air-conditioning system use to operate the recirculation control motor?

a. Vehicle speed b. In-car and outside temperatures
c. Engine oil temperature d. Evaporator temperature

 46. What is/are the causes of wind shield wiper motor running sluggishly?
a. Contact breaker gap is not correct b. Binding in spindle or gear
c. Excessive blade pressure d. All of these
  47. What may be the causes if fuel gauge needle always remains at empty?

a. Defective gauge b. Float arm sticking
c. Float punctured d. All of these
  48. The important parameter that can be controlled by electronic engine management system are
  a. Air fuel ratio b. Ignition and Injection timings
c. Idle speed d. All of these
Contd...6/-
18/A/C/S-4/4/E
49. As per service manual recommendations the level of engine oil should be checked when the engine is —
a. Cold b. Wormed up
c. Hot d. Very hot
50. Which of the following does not come under Vehicle Safety Technology?
 a. Air bags b. Remote key less entry system circuit
c. Tyre pressure monitoring system d. Night vision Assist

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