620+ Operating System Architecture Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Computer Science Engineering (CSE) .

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51.	Which command makes an empty directory
A.	mkdirectory
B.	makedirectory
C.	mkdir
D.	newdir
Answer» C. mkdir

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52.	Why is man command used
A.	to shut down
B.	search all files
C.	deleting files
D.	getting help command on format
Answer» D. getting help command on format

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53.	Which of the following features of unix may be used for interprocess communication
A.	signals
B.	pipes
C.	semaphores
D.	all of these
Answer» D. all of these

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54.	In a system,if 5 people are currently using the vi editor,then the number of corresponding processes will be
A.	1
B.	5
C.	2
D.	0
Answer» B. 5

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55.	The command echo welcome >/dev/tty
A.	echoes welcome in all the terminals that are switched on
B.	echoes welcome in all the " that are logged on
C.	echoes welcome only in the terminal in which it is run
D.	both (a) and ( c)
Answer» D. both (a) and ( c)

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56.	/dev/null
A.	is a file
B.	has write permission for all
C.	is the unix builtin dustbin
D.	all of these
Answer» D. all of these

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57.	The advantage of binary files over text files is that
A.	it is compact
B.	it can be accessed faster
C.	they are more reliable
D.	all of these
Answer» D. all of these

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58.	The permission bits of a filenoname,can be set to - rws - - * - - * by the command
A.	chmod 711 noname
B.	chmod go -rw noname
C.	chmod 2711 noname
D.	none of above
Answer» D. none of above

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59.	/bin/passwork has the user execution permission set to 's' because
A.	this facility assigns to the user, permissions of the program owner temporarily
B.	it should allow users who don\t have write permission to /etc/passwd to write to it
C.	/etc/passwd is write protected
D.	all of these
Answer» D. all of these

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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
A.	chmod u+s filex; chmod go -rw datfile
B.	chmod 4711 filex; chmod go -rw datfile
C.	chmod 4711 datfile; chmod go - rw filex
D.	both a & b
Answer» D. both a & b

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61.	Writing a c program that accepts input from keyboard,rather than from a file is advantageous because
A.	keyboard is a file that is already open
B.	it can be used in a pipe,if it writes to stdout
C.	both a & b
D.	non of above
Answer» C. both a & b

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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
A.	redirects the output of date to a file out f
B.	displays the output of date on the screen
C.	prints everything on screen
D.	prints the two messages on the screen
Answer» A. redirects the output of date to a file out f

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63.	The Hardware at centre of UNIX system provides………….
A.	basic services
B.	operating system with basic services
C.	kernel service
D.	none of these
Answer» B. operating system with basic services

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64.	Operating System is also called as ……….
A.	system kernel
B.	kernel
C.	both a and b
D.	none of these
Answer» C. both a and b

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65.	Program such as Shell and editors interact with kernel by invoking ……….
A.	process
B.	thread
C.	system calls
D.	none of these
Answer» C. system calls

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66.	…………responsible for exchanging data between kernel and programs
A.	system calls
B.	thread
C.	process
D.	none of these
Answer» A. system calls

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67.	what is a.out ?
A.	system user program
B.	private user program
C.	local program
D.	none of these
Answer» B. private user program

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68.	How many system calls in system V
A.	32
B.	64
C.	128
D.	16
Answer» B. 64

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69.	Out of 64 system calls in system V how many are frequently used…
A.	64
B.	32
C.	16
D.	128
Answer» B. 32

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70.	Non leaf node of the file system structure is …………..
A.	leaf node of file
B.	directory of file
C.	regular file
D.	path name
Answer» B. directory of file

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71.	Full path name starts with …..
A.	dot
B.	slash
C.	double slash
D.	non of these
Answer» B. slash

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72.	Text formatting program troff find …………. character at the end of each line
A.	newline
B.	slash
C.	dot
D.	none of these
Answer» A. newline

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73.	System accounting program acctcom find ……….
A.	variable length record
B.	fixed length record
C.	no record
D.	none of these
Answer» B. fixed length record

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74.	Directories are …….
A.	fixed files
B.	regular files
C.	variable files
D.	none of these
Answer» B. regular files

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75.	System treats the data in a directory as a ……………..
A.	byte stream
B.	bit stream
C.	stream
D.	none of these
Answer» A. byte stream

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76.	what is use of ls command ?
A.	to list names and attribute of files
B.	to list size of files
C.	to list length of files
D.	none of these
Answer» A. to list names and attribute of files

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77.	Access permission can be set to …………
A.	the file owner
B.	a file group
C.	everyone else
D.	all of these
Answer» D. all of these

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78.	The Newly created files are ………….. of the file system directory structure.
A.	main nodes
B.	root nodes
C.	leaf nodes
D.	middle nodes
Answer» C. leaf nodes

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79.	Unix system treats devices as a ……..
A.	hardware
B.	file
C.	byte
D.	none of these
Answer» B. file

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80.	Permission mode on newly created file will be……
A.	0666(octal)
B.	0666(hexadecimal)
C.	0999(octal)
D.	0798(hex)
Answer» A. 0666(octal)

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81.	Permission mode 0666(octal) means…………
A.	allowing all users acess to file for writing
B.	allowing all users acess to file for reading
C.	restrict to read and write
D.	allowing all users access to file for reading writing
Answer» D. allowing all users access to file for reading writing

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82.	All system calls return ……..if open or create call fails
A.	-2
B.	0
C.	1
D.	-1
Answer» D. -1

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83.	The open and create system calls returns an integer called a ……….
A.	file number
B.	file discriptor
C.	file variable
D.	none of these
Answer» B. file discriptor

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84.	File discriptor programs uses………………...
A.	to delete file
B.	to save file
C.	for subsequent references for file
D.	none of these
Answer» C. for subsequent references for file

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85.	The read system calls return 0 when ………..
A.	it reaches middle of file
B.	it reaches end of the file
C.	file is empty
D.	none of these
Answer» B. it reaches end of the file

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86.	When a process makes a system call ,its mode changes from………
A.	user to kernel
B.	kernel to user
C.	restricted to unrestricted
D.	unrestricted to restricted
Answer» A. user to kernel

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87.	The new process called, child process gets a ………... return value from fork.
A.	-1
B.	0
C.	2
D.	1
Answer» B. 0

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88.	The child process invoke …….to execute program copy .
A.	fork
B.	execl
C.	wait
D.	printf
Answer» B. execl

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89.	Which of the following system calls transforms an executable binary file into a process?
A.	fork
B.	exec
C.	ioct1
D.	longjmp
Answer» B. exec

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90.	Which of the following file names can be found in more than one directory?
A.	passwd
B.	bin
C.	date
D.	none of the above
Answer» A. passwd

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91.	The command that can be used to restrict incoming messages to a user is………..
A.	mesg
B.	halt
C.	grep
D.	sleep
Answer» A. mesg

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92.	The sort command in UNIX ….
A.	used to sort a file
B.	used to sort the list of files in a directory
C.	both a and b
D.	none of the above
Answer» A. used to sort a file

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93.	Which command is used to remove a directory?
A.	rd
B.	rmdir
C.	dldir
D.	rdir
Answer» B. rmdir

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94.	The tail command in UNIX……
A.	can be used to look at the tail or bottom of the file
B.	can be used to display the list of last 10 files in the current directory
C.	can be used to display the list of last 15 in the current directory
D.	none of the above
Answer» A. can be used to look at the tail or bottom of the file

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95.	Which command is used to remove a file ……
A.	rename
B.	mv
C.	rm
D.	del
Answer» C. rm

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96.	Which command will be used with vi editor to append text at end of line?
A.	a
B.	i
C.	a
D.	l
Answer» A. a

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97.	Which of the following command the file names in multiple columns?
A.	is–x
B.	is
C.	is–1
D.	is–f–x
Answer» B. is

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98.	Which command is used to display the device name of the terminal you are using?
A.	who
B.	ls
C.	tty
D.	stty
Answer» C. tty

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99.	Which command allows you to view your file 24 lines at a time ?
A.	more
B.	cat
C.	pg
D.	none of the above
Answer» A. more

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100.	Which of the following is not a communication command?
A.	write
B.	mail
C.	mesg
D.	grep
Answer» D. grep

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620+ Operating System Architecture Solved MCQs

Which command makes an empty directory

Why is man command used

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

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

The command echo welcome >/dev/tty

/dev/null

The advantage of binary files over text files is that

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

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

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

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

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

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

Operating System is also called as ……….

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

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

what is a.out ?

How many system calls in system V

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

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

Full path name starts with …..

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

System accounting program acctcom find ……….

Directories are …….

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

what is use of ls command ?

Access permission can be set to …………

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

Unix system treats devices as a ……..

Permission mode on newly created file will be……

Permission mode 0666(octal) means…………

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

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

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

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

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

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

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

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

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

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

The sort command in UNIX ….

Which command is used to remove a directory?

The tail command in UNIX……

Which command is used to remove a file ……

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

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

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

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

Which of the following is not a communication command?

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