SRIRAM ENGINEERING COLLEGE, PERUMALPATTUDEPARTMENT OF AUTOMOBILE ENGINEERING

AUTOMOTIVE ENGINES

QUESTIONS FROM UNIVERSITY EXAM

Semester: III Max. Marks: 100

PART – A (10 x 2 = 20 marks)

1. What is the use of air standard cycle?2. Draw the Otto cycle on P-V diagram3. what are the firing order used in 4 and 6 cylinder engines4. what is stiochiometric air fuel ratio5. what are the three basic types of carburetors6. what are the different methods of engine cooling 7. what is blow by8. what is flame front9. what are the various types of combustion chambers used in SI engines10. what is scvangening efficiency11. what is short circuiting 12. what is carnot cycle and its importance13. What are different air fuel mixtures on which an engine can operate 14. Write down the firing order for four and six cylinder engines15. what is indicator diagram16. what is the necessity of firing order in a multicylinder engines17. what are the mixture limits for inflammability18. what is the difference between a constant choke carburetor and a constant vacuum

carburetor19. what is a thermostat20. what is the need for providing crankcase ventilation21. what are the variable s that affect the knock of SI engines22. How is the location of the spark plug can influence knocking tendency23. why scavenging is important in two stroke engines compared to four stroke

engines 24. Define trapping efficiency25. List the different types of ignition system used in vehicles 26. What is the use of condenser in ignition system27. What are the main functions of air injection pump?28. What is meant by crank case ventilation?29. Write the reason for cooling an engine30. what is the advantage of air cooling system31. what is meant by abnormal combustion32. What is delay period and what are the factors that affect the delay period?33. Define enthalpy34. Write down the components of ignition system used in automobiles

35. Write down the possible faults in conventional ignition system

36. Draw the diagram for an ignition coil and name the components37. Write any four advantage of 4 stroke petrol engine over 2 stroke petrol engine38. write the air standard efficiency of an Otto cycle39. write ant four factor that affects the process of combustion40. what are the various requirement of good carburetor41. what is the main function of an spark plug42. write different methods of SI lubricating system43. write the reason for cooling an engine44. what is meant by abnormal combustion45. What is a homogeneous and heterogeneous mixture?46. what is opposed piston engine47. Define dwell angle and mention its importance48. Briefly explain about two types of spark plug used in automobiles49. List the advantage of Electronic ignition system with conventional type 50. Write down the firing order for four and six cylinder engines51. List the different types of ignition system used in vehicles 52. What is the use of condenser in ignition system53. Write down the components of ignition system used in automobiles54. Write down the possible faults in conventional ignition system PART – B (16 x 2 = 32 marks)

55. Compare four stroke and two stroke cycle engines and bring out their relative merits and demerits

56. Describe with suitables sketches the idling system and accelerating pump of a modern carburetor

57. sketch a mechanical fuel pump and describe its working58. Explain with a neat sketch the forced circulation cooling system59. Discuss the different properties of lubricants60. Discuss the design criteria for a S.I engine combustion chamber61. Explain with neat sketches the two different types of two stroke engines62. Explain the various scavenging pumps used in a two stroke engines 63. Discuss the two stroke engine construction and operation with neat sketches64. with a neat sketch explain the working principles of a simple carburetor65. Explain briefly the electronic fuel injection system used in some modern cars66. Explain with neat sketches the thermosypon cooling system and pressure cooling

system67. Discuss the various types of combustion chambers used in SI engines 68. Explain with a graph the three possible theoretical scvangening processes69. Explain with neat sketch the cross flow scvangening and uniflow scvangening 70. Briefly explain the principle of four stroke petrol engine with a simple sketch71. Draw the ideal and actual indicator diagram for a four stroke petrol engine and

explain why they differ each other.

72. Draw the sketch of a downdraught carburetor. How do the idle and low speed circuits work in this carburetor

73. Briefly explain the working principle of line fuel injection pump74. Explain the dry sump lubricating system with neat sketch75. What is an air cooling system and in which type of engine it is normally used.76. Explain the desirable properties of a good lubricant77. What are the various types of combustion chamber used in SI engines? explain

them briefly78. Write any one type of scavenging pump used in a 2 stroke petrol engine and

explain briefly.79. Define the following

i) Delivery ratioii) Trapping efficiencyiii) Relative cylinder chargeiv) Scavenging efficiency

80. A gas working on the Otto cycle has a cylinder of diameter 200 mm and stroke 250 m. The clearance volume is 1570 CC. Find the air standard efficiency. Assue Cp= 1.004 KJ/kg K and Cv = 0.7171 KJ/kg K for air.

81. With a suitable sketches explain the various modern automobiles carburetors82. Give brief account of the injection in SI engine83. Clearly explain the various Wet sump lubricating system. Compare wet sump and

dry sump lubrication84. With suitable sketches explain the liquid cooling system of an Automobile.85. Explain the phenomenon of knock in SI engine and compare with it with CI

engines86. Explain various scavenging pumps used in a two stroke engines87. what are the advantage and disadvantage of 2 stroke engine88. Explain with figures various types of combustion chambers used in SI engines.89. With the aid of a circuit diagram explain the working principles of a battery coil

ignition system.90. Describe the working principles of a centrifugal spark advance mechanism with neat diagram91. Describe the necessity of the spark advance mechanism in an engine92. With the aid of a diagram describe vacuum spark advance mechanism93. Draw the diagram for an ignition coil and name the components 94. With the aid of a circuit diagram explain the working principles of a battery coil

ignition system.95. Describe the working principles of a centrifugal spark advance mechanism with neat diagram97. Describe the necessity of the spark advance mechanism in an engine98. With the aid of a diagram describe vacuum spark advance mechanism