Quiznetik

Operating System Architecture | Set 1

1. What is an internal command in Unix ?

Correct : B. commands that are executred directly by the shell

2. What is major device number ?

Correct : A. it is an index to the kernel table that contains the address of all device driver functions known to the system

3. The game program,"space travel"for GECOS system was written in

Correct : C. fortran

4. What does OSS stand for

Correct : C. open source software

5. Which of the following is used to write disk block images from memory to disk

Correct : C. sync

6. How many line are there are in the result of date command

Correct : B. one

7. While providing a text processing system for the patent department at bell labs,the unix system was moved to in 1971

Correct : D. pdp-11

8. What is minor device number

Correct : D. it tells the device driver functionwhat actual physiacl device it is talking to and i/0 buffernig scheme to be used for data transfer

9. What is directory hierarchy ?

Correct : A. it is an organizational structure in which directories can contain files and other sub directories

10. what is the relationship of a filename to its inode

Correct : C. many to one

11. Unix os was first rewritten in C in

Correct : C. 1973

12. Among the directory entries inode and file contents which will be changed when a file is updated

Correct : B. only inode and file contents

13. what is the use of exec command

Correct : C. command that can be used to open files in shell scripts

14. Which of the following sections of an executable binary file has all un initialized data items

Correct : A. bss

15. The previous system administartor has put useless messages at login . What file do you edit to change the system message

Correct : A. /etc/motd

16. Suppose that a process is in BLOCKED state waiting for some i/o service. When a service is completed, it goes to the

Correct : B. ready state

17. Buffering mechanisms regulated the data between

Correct : D. buffer cache and file system

18. A thread is a ---- process

Correct : A. light weight

19. A RAID system is useful because --

Correct : C. increases disk storage capacity

20. NFS stands for

Correct : B. network file system

21. How many fields are there in /etc/passwd file

Correct : B. 7

22. Thomson and Ritchie published a paper describing unix system in

Correct : C. communicatio-ns of the acm

23. Command to reboot the system

Correct : C. shutdown -r now

24. grep means

Correct : A. global regular expression print

25. A history file

Correct : D. contains list of commands used during a session

26. Programs like shell and editors (ed and vi) interact with the kernal by invoking

Correct : A. system calls

27. Internal or external command is checked using

Correct : D. type

28. The standard name for executable files produced by c compiler is

Correct : C. a.out

29. script is run for successful login

Correct : A. /etc/profile

30. The root node in the file system is write as

Correct : A. /

31. interacts with inner part of kernel

Correct : B. shell

32. is used to stop a process

Correct : A. kill

33. directory attributes are displayed by

Correct : D. ls-l-d

34. The x in the cat x command is

Correct : A. binary file

35. what is the run level for shut down and reboot respectively

Correct : A. 0 and 6

36. The text formatting program traff

Correct : A. expects to find new line character at the end of each line of text

37. The system acctcom accounting program

Correct : B. expects to find fixed length record

38. permission to access the file is controlled by

Correct : C. access permissions

39. To the user,the unix system treats devices as if they are

Correct : D. files

40. Two invocations copy copy.c newcopy.c copy copy newcopy

Correct : C. both carrect

41. In processing environment of unix

Correct : A. a program is an executable file and process is an instance of the program in execution

42. The fork system call

Correct : D. creates a new process

43. What command do you have to use to go to parent directory

Correct : D. cd..

44. The command used to display a specified file

Correct : C. cat

45. root in unix system is represented by

Correct : D. /

46. what does cd.. Do ?

Correct : D. " " " " " " the parent of current working directory

47. What does command LS do

Correct : C. display of file & folders, present in the folder where you are

48. Why is PWD used

Correct : B. show present working directory

49. Which is the carrect command to list files & folders in unix

Correct : B. ls

50. How can you display a list of files including hidden files

Correct : B. ls-a

51. Which command makes an empty directory

Correct : C. mkdir

52. Why is man command used

Correct : D. getting help command on format

53. Which of the following features of unix may be used for interprocess communication

Correct : D. all of these

54. In a system,if 5 people are currently using the vi editor,then the number of corresponding processes will be

Correct : B. 5

55. The command echo welcome >/dev/tty

Correct : D. both (a) and ( c)

56. /dev/null

Correct : D. all of these

57. The advantage of binary files over text files is that

Correct : D. all of these

58. The permission bits of a filenoname,can be set to - rws - - * - - * by the command

Correct : D. none of above

59. /bin/passwork has the user execution permission set to 's' because

Correct : D. all of these

60. If are does not want anyone else to read or write to a file named datfile,except through a program in a file filex,then he may use

Correct : D. both a & b

61. Writing a c program that accepts input from keyboard,rather than from a file is advantageous because

Correct : C. both a & b

62. Consider the following program main ( ) { printf ("Aayush won a football match on \n"); system ("date"); printf("In Berlin"); } if a.out is the executable code corresponding to the above source code,then the command a.out >out f

Correct : A. redirects the output of date to a file out f

63. The Hardware at centre of UNIX system provides………….

Correct : B. operating system with basic services

64. Operating System is also called as ……….

Correct : C. both a and b

65. Program such as Shell and editors interact with kernel by invoking ……….

Correct : C. system calls

66. …………responsible for exchanging data between kernel and programs

Correct : A. system calls

67. what is a.out ?

Correct : B. private user program

68. How many system calls in system V

Correct : B. 64

69. Out of 64 system calls in system V how many are frequently used…

Correct : B. 32

70. Non leaf node of the file system structure is …………..

Correct : B. directory of file

71. Full path name starts with …..

Correct : B. slash

72. Text formatting program troff find …………. character at the end of each line

Correct : A. newline

73. System accounting program acctcom find ……….

Correct : B. fixed length record

74. Directories are …….

Correct : B. regular files

75. System treats the data in a directory as a ……………..

Correct : A. byte stream

76. what is use of ls command ?

Correct : A. to list names and attribute of files

77. Access permission can be set to …………

Correct : D. all of these

78. The Newly created files are ………….. of the file system directory structure.

Correct : C. leaf nodes

79. Unix system treats devices as a ……..

Correct : B. file

80. Permission mode on newly created file will be……

Correct : A. 0666(octal)

81. Permission mode 0666(octal) means…………

Correct : D. allowing all users access to file for reading writing

82. All system calls return ……..if open or create call fails

Correct : D. -1

83. The open and create system calls returns an integer called a ……….

Correct : B. file discriptor

84. File discriptor programs uses………………...

Correct : C. for subsequent references for file

85. The read system calls return 0 when ………..

Correct : B. it reaches end of the file

86. When a process makes a system call ,its mode changes from………

Correct : A. user to kernel

87. The new process called, child process gets a ………... return value from fork.

Correct : B. 0

88. The child process invoke …….to execute program copy .

Correct : B. execl

89. Which of the following system calls transforms an executable binary file into a process?

Correct : B. exec

90. Which of the following file names can be found in more than one directory?

Correct : A. passwd

91. The command that can be used to restrict incoming messages to a user is………..

Correct : A. mesg

92. The sort command in UNIX ….

Correct : A. used to sort a file

93. Which command is used to remove a directory?

Correct : B. rmdir

94. The tail command in UNIX……

Correct : A. can be used to look at the tail or bottom of the file

95. Which command is used to remove a file ……

Correct : C. rm

96. Which command will be used with vi editor to append text at end of line?

Correct : A. a

97. Which of the following command the file names in multiple columns?

Correct : B. is

98. Which command is used to display the device name of the terminal you are using?

Correct : C. tty

99. Which command allows you to view your file 24 lines at a time ?

Correct : A. more

100. Which of the following is not a communication command?

Correct : D. grep