Quiznetik

Internal Combustion Engines (I.C. Engines) | Set 2

1. The choke is closed when the engine is

Correct : C. cold

2. Lean air mixture is required during

Correct : D. cruising

3. The limits of air-fuel for SI engine are

Correct : A. 8/1 to 18/1

4. For maximum thermal efficiency, the fuel-air mixture in SI engines should be

Correct : A. lean

5. During starting petrol engines require

Correct : C. rich mixture

6. Economizer is used to provide enriched mixture during

Correct : D. full throttle operation

7. When the throttle is suddenly opened, the mixture of the simple carburetor tends to become

Correct : B. lean

8. Precise petrol injection system is

Correct : C. throttle body injection

9. The choke in an automobile meant for supplying

Correct : B. rich mixture

10. Modern carburetors provide the correct quality of air-fuel mixture during

Correct : D. all conditions

11. A simple carburetor supplies rich mixture during

Correct : D. accelerating

12. Fuel injector is used for

Correct : B. CI engines

13. Advantage of air injection system is

Correct : D. all of the above

14. Commonly used injection system in automobiles is

Correct : B. solid injection

15. Fuel injection pressure in solid injection system is around

Correct : D. 200-250 bar

16. Fuel filters do not use generally

Correct : B. paper

17. Fuel is injected in a four-stroke CI engine

Correct : C. at the end of compression stroke

18. Injection system in which the pump and the injector nozzle is combined in one housing is known as

Correct : C. unit injector system

19. Main advantage of pintaux nozzle is

Correct : A. better cold starting performance

20. the most accurate gasoline injection system is

Correct : B. port injection

21. Advantage of fuel injection in SI engine is

Correct : C. increased volumetric efficiency

22. ‘MPFI’ stands for

Correct : A. Multi point fuel injection

23. In carburetor, Choke is incorporated

Correct : A. Before the venturi

24. The following factors affect the process of carburetion

Correct : D. All of the above

25. In MPFI _____ is used to spray fuel into engine.

Correct : B. Suction pressure of engine

26. L-MPFI system uses

Correct : A. port injection

27. D-MPFI system uses

Correct : B. manifold injection

28. Common rail injection system uses injection pressures of the order

Correct : D. 1500 bar

29. Continuous injection system usually has

Correct : B. rotary pump

30. The cold start injector

Correct : C. gives rich air-fuel ratio

31. ECU is an electronic injection system used for

Correct : A. calculating the appropriate injection timing

32. With EFI (ELECTRONIC FUEL INJECTION) of diesel engines

Correct : B. very high injection pressure can be obtained

33. EFI system can achieve

Correct : D. all of the above

34. The first vehicle in India equipped with MPFI system in Indian automobile industry

Correct : B. Daewoo Matiz

35. The fuel in diesel engine is normally injected at pressure of

Correct : D. 90-130 kg/cm2

36. The specific fuel consumption per BHP hour for diesel engine is approximately

Correct : B. 0.2 kg

37. The specific fuel consumption per BH hour for a petrol engine is approximately

Correct : C. 0.25 kg

38. The air-fuel ratio of the petrol engine is controlled by

Correct : D. carburettor

39. Pour point of fuel oil is the

Correct : B. temperature at which it solidifies or congeals

40. A 5 BHP engine running at full load would consume diesel of the order of

Correct : B. 1 kg/hr

41. The secondary winding of ignition coil consists of

Correct : C. many turns of fine wire

42. Dwell is the time

Correct : A. for which the points remain closed

43. Dwell period

Correct : B. is inversely proportional to engine speed

44. If the contact breaker gap is small, it results in

Correct : C. rapid burning of the pointer gaps

45. For a four cylinder engine operating at N rpm, the contact breaker must make and break the circuit

Correct : B. 2N times

46. Contact breaker should be set

Correct : C. after adjustment of dwell angle

47. Dwell meter is used for

Correct : B. contact breaker gap

48. For a four cylinder vertical engine, the commonly used firing order is

Correct : C. 1-3-4-2

49. For engine operating with rich mixtures the optimum spark timing

Correct : A. must be advanced

50. For peak lead operation, the spark advance

Correct : A. must be decreased

51. Ignition timing is adjusted by

Correct : B. stroboscopic light

52. Vacuum advance mechanism shifts the ignition point under

Correct : C. part load operation

53. Which of the following statement is wrong?

Correct : D. retarded timing causes burning of the hydrocarbons in the exhaust

54. Choose the correct statement from the following

Correct : D. magneto ignition system has poor quality of spark during starting

55. Battery ignition system

Correct : D. all of the above

56. Method of governing used in petrol engine is

Correct : C. quantity governing

57. Pick up the false statement

Correct : D. S.I. engines are quality-governed engines.

58. The centrifugal type supercharger is preferable only for

Correct : A. low speeds

59. The advantage of Root's supercharger is

Correct : B. minimum maintenance

60. Supercharging air compressor is driven by

Correct : B. engine itself

61. If turbochargers compressor is driven by

Correct : A. exhaust gas turbine

62. Cooling after compression is necessary to

Correct : C. both (a) and (b)

63. Volumetric efficiency of supercharged engine is

Correct : A. between 100 - 110%

64. Supercharging is normally done in

Correct : D. none of the above

65. Compared to engine driven supercharger the exhaust driven super charger is

Correct : C. utilizes the exhaust energy of the engine

66. Types of supercharger are

Correct : C. centrifugal type

67. The operation of forcing additional air under pressure in the engine cylinder is known as

Correct : C. supercharging

68. Supercharging is essential in

Correct : D. aircraft engines.

69. The output of a diesel engine can be increased without increasing the engine revolution or size in following way

Correct : D. supercharging.

70. Supercharging is the process of

Correct : A. supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere

71. Pick up the wrong statement about supercharging

Correct : D. supercharging results in fuel economy

72. The reason for supercharging in any engine is to

Correct : C. reduce weight and bulk for a given out-put

73. For the same power developed in I.C. engines, the cheaper system is

Correct : B. supercharged

74. In SI engines maximum flame speed is obtained when the equivalent ratio is between

Correct : A. 1.1 and 1.2

75. In SI engines flame speed increases

Correct : C. both (a) and (b)

76. with increase in compression ratio flame speed

Correct : A. increases

77. With increase in speed the crank angle required for fame propagation

Correct : C. not affected

78. Increasing the compression ratio in SI engines the knocking tendency

Correct : B. increases

79. Decreasing the cooling water temperature in SI engines the knocking tendency

Correct : B. decreases

80. Detonation in SI engines occur due to

Correct : C. autoignition of the charge after the spark in struck

81. Desirable characteristics of the combustion chamber for SI engines to avoid knock is

Correct : D. all of the above

82. In CI engines with increase in compression ratio the delay period

Correct : C. first increases and then decreases

83. Knocking takes place in CI engines

Correct : A. at the start of combustion

84. In CI engines knocking tendency increases with

Correct : C. decrease in compression ratio

85. In CI engines by increasing inlet air pressure the knocking tendency

Correct : B. decreases

86. Open combustion chambers in CI engines require

Correct : C. both (a) and (b)

87. The advantages of the indirect injection combustion chambers are

Correct : C. both (a) and (b)

88. In CI engines the delay period is affected by

Correct : D. all of the above

89. Crankcase explosion in I.C. engines usually occurs as

Correct : A. first a mild explosion followed by a bi explosion

90. Compression loss in I.C engines occurs duto

Correct : D. all of the above.

91. It the temperature of intake air in IC engines is lowered, then its efficiency will

Correct : A. increase

92. The precess of breaking up or a liquid into fine droplets by spraying is called

Correct : D. atomisation.

93. As a result of detonation in an I.C. engine, following parameter attains very high value

Correct : B. rate of rise of pressure

94. Which of the following statements is correct?

Correct : D. All reversible engines working between same temperature limits have same-efficiency

95. The accumulation of carbon in a cylinder results in increase of

Correct : D. effective compression ratio

96. In diesel engine the diesel fuel injected intc cylinder would burn instantly at about compressed air temperature of

Correct : C. 1000°C

97. In a cycle, the spark lasts roughly for

Correct : D. 0.001 sec

98. Excess quantities of sulphur in diesel fuel are Objectionable because it may cause the following

Correct : D. detonation

99. Which of the following is false statement. Some of the methods used to reduce diesel smoke are as follows

Correct : C. increasing the compression ratio

100. A high flame speed is obtained in diesel engine when air fuel ratio is

Correct : D. about 10% rich mixture