COM (Component Object Model) MCQ Questions Answers

1. As a COM programmer, by which method would you destroy a COM object ?

2. IUnknown is an example of which kind of interface ?

3. Which interface is for accessing type libraries ?

4. CLSIDs are GUIDs that refer to :

5. Which is the incorrect statement regarding interfaces ?

6. DCOM is ideally suited to Internet technology for business applications. Which of the following would not support the above statement ?

7. Other than DCOM, which other IPC mechanism can be used ?

8. MTA stands for :

9. How many bits is a GUID ?

10. COM is not :

11. Which COM interface supports automation ?

12. Which one is a technology based on COM ?

13. IID stands for :

14. A stub is :

15. COM calls it classes :

16. Which parameters do you have to pass to the CoCreateInstance function ?

17. In which file is the Component Object Library implemented on Windows NT and Windows 95/98 ?

18. By which method of the IUnknown interface do clients dynamically discover at run-time whether or not an interface is supported by a component object ?

19. DCOM is an IPC mechanism.Here IPC stands for :

20. The threading model that defined a set of isolated but identical processing spaces for thread execution is called :

21. UDT stands for :

22. Which one is the correct statement regarding IDL ?

23. The implementation of the interfaces is done through :

24. Identify the incorrect statement from the following :

25. An interface that can be seen only within the object model or component in which it is defined is scoped as :

26. A dual interface is one :

27. An interface that can be seen only in the class in which it is defined is scoped as :

28. What is the similarity/relation between named pipes and DCOM ?

29. In which tool/language, can you make COM components ?

30. When a GUID identifies an interface, it is known as a :

31. GUID stands for :

32. Which method would you use to create new GUIDs ?

33. How many fields does a HRESULT consist of ?

34. The main goal of COM is :

35. What mechanism is provided by COM for reuse of code ?

36. A self-registering component is one :

37. COM stands for :

38. Which statement is not true regarding interfaces ?

39. Which language does COM prescribe for the creation of components ?

40. Which compiled element does not run in-process ?

41. CLSID stands for :

42. The number of methods in the IUnknown interface is :

43. Point out the incorrect statement regarding proxies :

44. Following are some statements regarding interfaces. Which is the only incorrect one ?

45. What is the mechanism used in COM to uniquely identify components ?

46. Which statement is wrong about the benefits of type libraires ?

47. If an object does not support a requested interface, QueryInterface returns:

48. Standard marshalling is provided by which file ?

49. An interface is :

50. The extension of a type library is :

51. By which method of the IUnknown interface, can a client obtain pointers to other routines by requesting an interface pointer ?

52. Choose the false statement from the following regarding interfaces :

53. Which are the methods of the IUnknown interface ?

54. What technique does DCOM use to handle garbage collection of objects ?

55. Which one is a disadvantage of MIDL ?

56. Identify the incorrect statement regarding vtables :

57. Which statement is incorrect regarding the LockServer method ?

58. Which one is a COM interface for database access ?

59. Which one is not an objective of COM ?

60. Which approach to binding will result in the best performance ?

61. A component category is identified by :

62. Identification of the COM object stored in the Windows registry is known as :

63. MIDL stands for :

64. Which interface must be supported by a COM object ?

65. Which one is not a feature of COM ?

66. How many different kinds of interfaces are there in COM?

67. Which languages/tools can interact with COM through dispatch interfaces ?

68. How many bytes is a GUID ?

69. The AddRef method of the IUnknown interface is :

70. Which statement is incorrect regarding the IUnknown interface ?

71. What utility will you use to install and run servers remotely via DCOM ?

72. COM provides location transparency by :

73. Which is the incorrect statement about GUIDs ?

74. The LockServer method is used to :

75. When a GUID is used to identify a COM object, it is known as a :

76. What are the various types of marshalling ?

77. IIDs are GUIDs that refer to :

78. What function can you use to add information about a type library to the system registry ?

79. Which one is not a disadvantage of MIDL ?

80. Which interface is to be implemented by a class which is designed especially to manufacture other COM objects ?

81. Which statement regarding DCOM is incorrect ?

82. Which statement is incorrect regarding dispatch interfaces ?

83. IClassFactory is an example of which kind of interface ?

84. How are interfaces versioned ?

85. The basic unit of thread safety in COM is called a :

86. A proxy is :

87. Which interface is for accessing type information ?

88. Under what registry key will the pathname of an out-of-process COM server be found ?

89. Which interface is used by a COM-using program to invoke a COM object's properties, methods and events by name ?

90. Which one is the only feature of COM ?

91. Which statement regarding marshalling code is not true ?

92. An ActiveX control has persistent properties.Which interface must it implement ?

93. The component needs to be run in a separate space or separate thread from the client application.Which type of server would you use ?

94. How is the instancing property value of an externally creatable class different from a dependent object class ?

95. Components can include :

96. Which is the base interface ?

97. You want to register a COM component named mydll.dll. Which one is the correct syntax for registering the component ?

98. IDL stands for :

99. Which one is not a type of identifier ?

100. In which case is marshalling code not used ?