In a diesel engine, the fuel is ignited by

heat resulting from compressing air that is supplied for combustion

Scavenging air in diesel engine means

air used for forcing burnt gases out of engine’s cylinder during the exhaust period

air used for combustion sent under pres-sure

forced air for cooling cylinder

burnt air containing products of combustion

air used for forcing burnt gases out of engine’s cylinder during the exhaust period

Supercharging is the process of

supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere

injecting excess fuel for raising more load

supplying compressed air to remove combustion products fully

Compression ratio of LC. engines is

the ratio of volumes of air in cylinder before compression stroke and after compression stroke

volume displaced by piston per stroke and clearance volume in cylinder

ratio of pressure after compression and before compression

The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is

more or less depending on power rating

In a typical medium speed 4-stroke cycle diesel engine the inlet valve

opens at 20° before top dead center and closes at 35° after the bottom dead center

opens at top dead center and closes at bottom dead center

opens at 10° after top dead center and closes 20° before the bottom dead center

The pressure and temperature at the end of compression stroke in a petrol engine are of the order of

6 – 12 kg/cm2 and 250 – 350°C

4 – 6 kg/cm2 and 200 – 250°C

6 – 12 kg/cm2 and 250 – 350°C

12 – 20 kg/cm2 and 350 – 450°C

20 – 30 kg/cm2 and 450 – 500°C

30 – 40 kg/cm2 and 500 – 700°C.

The thermal efficiecny of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will

may increase or decrease depending on other factors

Pick up the wrong statement

petrol engines occupy more space than diesel engines for same power output.

2-stroke engine can run in any direction

In 4-stroke engine, a power stroke is obtained in 4-strokes

thermal efficiency of 4-stroke engine is more due to positive scavenging

petrol engines work on otto cycle

petrol engines occupy more space than diesel engines for same power output.

Crankcase explosion in I.C. engines usuall occurs as

first a mild explosion followed by a bi explosion

first a big explosion followed by a mil explosion

both mild and big explosions occi simultaneously

Compression loss in I.C engines occurs duto

increase in clearance volume caused b bearing-bushing wear

The air requirement of a petrol engine during starting compared to theoretical airequired for complete combustion is

may be more or less depending on engine capacity

Pick up the false statement

S.I. engines are quality-governed engines.

Thermal efficiency of diesel engine i about 34%

Theoretically correct mixture of air am petrol is approximately 15 : 1

High speed compression engines operate on dual combustion cycle

Diesel engines are compression ignition engines

S.I. engines are quality-governed engines.

If one cylinder of a diesel engine receives more fuel than the others, then for that cylinder the

piston rings would stick into piston grooves

exhaust temperature will be high

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

increase upto certain limit and then decrease

decrease upto certain limit and then in-crease.

In a typical medium speed 4-stroke cycle diesel engine

compression starts at 35° after bottom dead center and ends at top dead center

compression starts at bottom dead center and ends at top dead center

compression starts at 10° before bottom dead center and, ends just before top dead center

For the same compression ratio

Otto cycle is more efficient than the Diesel

Diesel cycle is more efficient’than Otto

both Otto and Diesel cycles are, equally efficient

compression ratio has nothing to do with efficiency

which is more efficient would depend on engine capacity.

Which of the following statements is correct?

All reversible engines working between same temperature limits have same-efficiency

All the irreversible engines have same efficiency

All the reversible engines have same efficiency

Both Rankine and Caront cycles have same efficiency between same temperature limits

All reversible engines working between same temperature limits have same-efficiency

Between same temperature limits, both petrol and diesel engines have same efficiency.

In a typical medium speed, 4-stroke cycle diesel engine

fuelinjection starts at 10° before to dead center and ends at 20° after tor dead center

fuel injection starts at top dead center and ends at 20° after top dead center

fuel injection starts at just before top dead center and ends just after top deac center

Diesel fuel, compared to petrol is

just about the same difficult to ignite

The rating of a diesel engine, with increase in airintlet temperature, will

first decrease linearly and then increase parabolically.

IC Engines MCQ Interview Questions and Answers Quiz

93.

. Volatility of diesel fuel oil is

minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame

temperature at which it solidifies or congeals

it catches fire without external aid

indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off

temperature at which it flows easily.

1. The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft

2. In a diesel engine, the fuel is ignited by

3. Scavenging air in diesel engine means

4. Supercharging is the process of

5. Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged ?

6. The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called

7. Compression ratio of LC. engines is

8. The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is

9. The calorific value of gaseous fuels is expressed in terms of

10. If the intake air temperature of I.C. engine increases, its efficiency will

11. All heat engines utilize

12. An engine indicator is used to determine the following

13. Fuel oil consumption guarantees for I .C. engine are usually based on

14. If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the %age increase in efficiency will be

15. In case of gas turbines, the gaseous fuel consumption guarantees are based on

16. In a typical medium speed 4-stroke cycle diesel engine the inlet valve

17. The pressure and temperature at the end of compression stroke in a petrol engine are of the order of

18. The pressure at the end of compression in the case of diesel engine is of the order of

19. The maximum temperature in the I.C. engine cylinder is of the order of

20. The thermal efficiecny of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will

21. Pick up the wrong statement

22. Combustion in compression ignition engines is

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

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

25. The temperature of interior surface of cylinder wall in normal operation is not allowed to exceed

26. Crankcase explosion in I.C. engines usuall occurs as

27. Compression loss in I.C engines occurs duto

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

29. The air requirement of a petrol engine during starting compared to theoretical airequired for complete combustion is

30. The inlet value of a four stroke cycle I.C engine remains open for nearly

31. Which of the following is not an interns combustion engine

32. Pick up the false statement

33. If one cylinder of a diesel engine receives more fuel than the others, then for that cylinder the

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

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

36. In a typical medium speed 4-stroke cycle diesel engine

37. For the same compression ratio

38. The precess of breaking up or a lipuid into fine droplets by spraying is called

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

40. Which of the following statements is correct?

41. Most high speed compression engines operate on

42. The accunmulation of carbon in a cylinder results in increase of

43. Which of the following medium is compressed in a Diesel engine cylinder

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

45. In a typical medium speed, 4-stroke cycle diesel engine

46. Diesel fuel, compared to petrol is

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

48. When crude oil is heated, then which of the following hydrocarbon is given off first.

49. The rating of a diesel engine, with increase in airintlet temperature, will

50. A 75 cc engine has following parameter as 75 cc

51. A heat engine utilises the

52. Gaseous-fuel guarantees are based on

53. Fuel consumption of diesef engines is not guaranteed at one quarter load because at such low loads

54. Polymerisation is a chemical process in which molecules of a compound become

55. The term scavenging is generally associated with

56. In diesel engine, the compression ratio in comparison to expansion ratio is (G) more

57. The cam shaft of a four stroke I.C. engine running at 1500 rmp will run at

58. Engine pistons ‘are usually made of aluminium alloy because it

59. Most high speed compression engines operate on

60. The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is

61. A diesel engine as compared to petrol engine (both running ar rated load) is

62. The size of inlet valve of.an engine in comparison to exhaust valve is

63. In a cycle, the spark lasts roughly for

64. Which of the following is false statement : Excess quantities of sulphur in diesel fuel are Objectionable because it may cause the following

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

66. The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be

67. Pick up the wrong statement about supercharging

68. The actual volume of fresh charge admitted in 4-stroke petrol engine is

69. The magneto in an automobile is basically

70. The reason for supercharging in any engine is to

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

72. Supercharging is essential in

73. The minimum cranking speed in case of petrol engine is about

74. In a typical medium speed 4 stroke cycle diesel engine

75. Flash point of fuel oil is

76. The mean effective pressure obtained from engine indicator indicates the

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

78. Installation of supercharger on a four-cycle diesel engine can result in the following percentage increase in power

79. Scavenging is usually done to increase

80. Which of the following is the lightest and most volatile liquid fuel

1.

The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft

2.

In a diesel engine, the fuel is ignited by

3.

Scavenging air in diesel engine means

4.

Supercharging is the process of

5.

Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged ?

6.

The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called

7.

Compression ratio of LC. engines is

8.

The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is

9.

The calorific value of gaseous fuels is expressed in terms of

10.

If the intake air temperature of I.C. engine increases, its efficiency will

11.

All heat engines utilize

12.

An engine indicator is used to determine the following

13.

Fuel oil consumption guarantees for I .C. engine are usually based on

14.

If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the %age increase in efficiency will be

15.

In case of gas turbines, the gaseous fuel consumption guarantees are based on

16.

In a typical medium speed 4-stroke cycle diesel engine the inlet valve

17.

The pressure and temperature at the end of compression stroke in a petrol engine are of the order of

18.

The pressure at the end of compression in the case of diesel engine is of the order of

19.

The maximum temperature in the I.C. engine cylinder is of the order of

20.

The thermal efficiecny of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will

21.

Pick up the wrong statement

22.

Combustion in compression ignition engines is

23.

The fuel in diesel engine is normally injected at pressure of

24.

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

25.

The temperature of interior surface of cylinder wall in normal operation is not allowed to exceed

26.

Crankcase explosion in I.C. engines usuall occurs as

27.

Compression loss in I.C engines occurs duto

28.

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

29.

The air requirement of a petrol engine during starting compared to theoretical airequired for complete combustion is

30.

The inlet value of a four stroke cycle I.C engine remains open for nearly

31.

Which of the following is not an interns combustion engine

32.

Pick up the false statement

33.

If one cylinder of a diesel engine receives more fuel than the others, then for that cylinder the

34.

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

35.

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

36.

In a typical medium speed 4-stroke cycle diesel engine

37.

For the same compression ratio

38.

The precess of breaking up or a lipuid into fine droplets by spraying is called

39.

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

40.

Which of the following statements is correct?

41.

Most high speed compression engines operate on

42.

The accunmulation of carbon in a cylinder results in increase of

43.

Which of the following medium is compressed in a Diesel engine cylinder

44.

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

45.

In a typical medium speed, 4-stroke cycle diesel engine

46.

Diesel fuel, compared to petrol is

47.

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

48.

When crude oil is heated, then which of the following hydrocarbon is given off first.

49.

The rating of a diesel engine, with increase in airintlet temperature, will

50.

A 75 cc engine has following parameter as 75 cc

51.

A heat engine utilises the

52.

Gaseous-fuel guarantees are based on

53.

Fuel consumption of diesef engines is not guaranteed at one quarter load because at such low loads

54.

Polymerisation is a chemical process in which molecules of a compound become

55.

The term scavenging is generally associated with

56.

In diesel engine, the compression ratio in comparison to expansion ratio is (G) more

57.

The cam shaft of a four stroke I.C. engine running at 1500 rmp will run at

58.

Engine pistons ‘are usually made of aluminium alloy because it

59.

Most high speed compression engines operate on

60.

The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is

61.

A diesel engine as compared to petrol engine (both running ar rated load) is

62.

The size of inlet valve of.an engine in comparison to exhaust valve is

63.

In a cycle, the spark lasts roughly for

64.

Which of the following is false statement : Excess quantities of sulphur in diesel fuel are Objectionable because it may cause the following

65.

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

66.

The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be

67.

Pick up the wrong statement about supercharging

68.

The actual volume of fresh charge admitted in 4-stroke petrol engine is

69.

The magneto in an automobile is basically

70.

The reason for supercharging in any engine is to

71.

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

72.

Supercharging is essential in

73.

The minimum cranking speed in case of petrol engine is about

74.

In a typical medium speed 4 stroke cycle diesel engine

75.

Flash point of fuel oil is

76.

The mean effective pressure obtained from engine indicator indicates the

77.

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

78.

Installation of supercharger on a four-cycle diesel engine can result in the following percentage increase in power

79.

Scavenging is usually done to increase

80.

Which of the following is the lightest and most volatile liquid fuel