Disk Operating System (DOS) MCQ Questions and Answers
1. The main purpose of DOS is to:
A) Connect to the Internet
B) Manage files and hardware resources
C) Run graphical applications only
D) Provide multitasking support
2. Which of the following is a valid DOS file name?
A) data.report
B) mydocument.txt
C) report.doc
D) longfilename.txt
3. In DOS, the maximum length of a file name (excluding extension) is:
A) 12 characters
B) 10 characters
C) 8 characters
D) 6 characters
4. Which command displays the current directory?
A) SHOWDIR
B) PATH
C) CD
D) DIRNAME
5. The command used to delete all files in a directory is:
A) DEL *
B) ERASEALL
C) DELETE ALL
D) REMOVE
6. Which of the following is the DOS system file responsible for command interpretation?
A) MSDOS.SYS
B) COMMAND.COM
C) CONFIG.SYS
D) AUTOEXEC.BAT
7. The DOS file extension “.BAT” represents:
A) Backup File
B) Batch File
C) Binary Application Table
D) Base Attribute Type
8. In DOS, which symbol is used as a wildcard for multiple characters?
A) ?
B) ^
C) &
D) *
9. Which command is used to create a directory in DOS?
A) MAKEDIR
B) MD
C) CRDIR
D) NEWDIR
10. The CONFIG.SYS file is primarily used to:
A) Execute user programs
B) Store passwords
C) Configure hardware and system drivers
D) Delete temporary files
11. The root directory of a drive is represented by:
A)
B) base:/
C) \
D) /main
12. Which command displays files in the current directory?
A) SHOW
B) DIR
C) LISTALL
D) VIEW
13. Which key combination is used to terminate a running program in DOS?
A) Ctrl + S
B) Alt + F4
C) Ctrl + C
D) Shift + Esc
14. The file MSDOS.SYS is responsible for:
A) Command interpretation
B) Core system functions and file management
C) Disk formatting
D) Printer control
15. The extension of a hidden system file in DOS is usually:
A) .BIN
B) .COM
C) .SYS
D) .EXE
16. Which DOS version introduced support for extended partitions?
A) 1.0
B) 2.0
C) 3.3
D) 5.0
17. To rename a file in DOS, the command is:
A) CHANGE
B) REN
C) TITLE
D) EDIT
18. Which of the following is NOT a valid internal command?
A) CLS
B) FORMAT
C) COPY
D) DIR
19. Which command clears the screen in DOS?
A) ERASE
B) CLS
C) RESET
D) CLR
20. The AUTOEXEC.BAT file is executed:
A) Automatically at startup
B) When the user logs off
C) Only on shutdown
D) After typing AUTOEXEC
21. The maximum size of a DOS partition using FAT16 is:
A) 1 GB
B) 2 GB
C) 2 GB
D) 4 GB
22. Which DOS command copies files from one location to another?
A) MOVE
B) COPY
C) TRANSFER
D) SHIFT
23. Which character represents the current drive in a command path?
A) /
B) .
C) :
D) *
24. In DOS, the command “CD..” means:
A) Change directory to root
B) Move up one directory level
C) Display current directory
D) Delete current directory
25. What is the purpose of the “VER” command?
A) Verify files
B) Display DOS version
C) View errors
D) Validate disk
26. The command used to check disk status is:
A) CHKDSK
B) DISKVIEW
C) VERIFY
D) SCANDISK
27. The system prompt “C:>” indicates:
A) File in D drive
B) Root of floppy disk
C) Root directory of drive C
D) Subfolder of system drive
28. Which command displays the contents of a text file?
A) DIR
B) EDIT
C) TYPE
D) VIEW
29. To copy all files with the extension .TXT, the command is:
A) COPY .TXT
B) COPY *
C) COPY *.TXT
D) COPY TEXT
30. Which command removes an empty directory?
A) DELDIR
B) RD
C) DELETEDIR
D) REMOVE
31. Which command allows users to view or change system date?
A) CLOCK
B) DATE
C) TIME
D) NOW
32. Which DOS command is used to format a disk?
A) DISKNEW
B) ERASE
C) FORMAT
D) INIT
33. To check or change the system time, use:
A) TIME
B) DATE
C) CLOCK
D) SHOWTIME
34. The primary file system used by DOS is:
A) NTFS
B) EXT2
C) FAT16
D) HPFS
35. Which command shows all hidden files?
A) DIR /A:H
B) DIR /ALL
C) DIR /S
D) VIEW /H
36. The “PATH” command is used to:
A) Change drive
B) Set directory search path for executables
C) Rename a file
D) Display directories
37. Which of these is a valid device name in DOS?
A) CON
B) TTY
C) DISP
D) PRINTER1
38. The “VOL” command displays:
A) Volume of disk space
B) Disk label and serial number
C) Directory volume
D) File size
39. What is the purpose of the “LABEL” command?
A) Rename files
B) Assign or change disk label
C) Delete directories
D) Edit configuration files
40. Which file runs automatically after DOS boots?
A) SYSTEM.INI
B) AUTOEXEC.BAT
C) WIN.INI
D) CONFIG.TXT
41. Which symbol is used for comments inside a batch file?
A) /C
B) \
C) %
D) REM
42. In a batch file, “ECHO OFF” is used to:
A) Turn the monitor off
B) Disable keyboard input
C) Hide command display during execution
D) Stop program output
43. What does “ECHO.” do in a batch file?
A) Prints a blank line
B) Prints file names
C) Pauses the script
D) Deletes temporary files
44. Which command is used to display a user-defined message in DOS?
A) TYPE
B) ECHO
C) PRINT
D) MSG
45. To pause execution in a batch file until a key is pressed:
A) PAUSE
B) WAIT
C) STOP
D) HALT
46. What does “CALL” do in DOS batch scripting?
A) Invokes another batch file and returns control
B) Stops the script
C) Executes system interrupt
D) Creates a loop
47. In a batch file, variables are enclosed with:
A) @ @
B) $ $
C) % %
D) & &
48. Which command is used to compare two files?
A) COMPARE
B) FC
C) CMP
D) MATCH
49. The command used to verify file writing to disk is:
A) WRITE
B) VERIFY
C) CONFIRM
D) TEST
50. Which DOS command displays system memory information?
A) MEMINFO
B) MEM
C) SYSTEM
D) RAMVIEW
51. The “SYS” command is used to:
A) Copy files
B) Display system configuration
C) Transfer system files to make a disk bootable
D) Scan disk for errors
52. In DOS, device drivers are loaded using:
A) AUTOEXEC.BAT
B) CONFIG.SYS
C) DRIVER.EXE
D) SYSTEM.BAT
53. Which command displays the tree structure of directories?
A) DIR /TREE
B) TREE
C) STRUCTURE
D) SHOWDIR
54. What is the purpose of the “MODE” command?
A) Change file attributes
B) Configure devices like COM ports and printers
C) Display system mode
D) Set date and time
55. Which DOS command displays system environment variables?
A) VARLIST
B) SET
C) SHOWENV
D) CONFIG
56. The command “DIR /P” is used to:
A) Print the directory
B) Display directory one screen at a time
C) Pause and delete files
D) Show protected files
57. Which key is used for command auto-completion in DOS?
A) Tab
B) Enter
C) Esc
D) Ctrl
58. What is the maximum number of characters in a DOS command line?
A) 80
B) 100
C) 127
D) 255
59. The command “COPY CON FILE.TXT” allows:
A) Creating a file from console input
B) Copying console to memory
C) Configuring network
D) Connecting disks
60. Which command is used to redirect output to a file?
A) >
B) >
C) <
D) >>
61. The symbol “>>” in DOS means:
A) Replace output file
B) Append output to file
C) End of command
D) None of the above
62. What is the function of the “PROMPT” command?
A) Reset command prompt
B) Change the appearance of the command prompt
C) Delete prompt
D) Set default drive
63. Which command displays the list of all running TSR programs?
A) RUN
B) TASKLIST
C) MEM /C
D) VIEWTSR
64. DOS primarily runs in which mode of CPU operation?
A) Protected Mode
B) Hyper Mode
C) Real Mode
D) Virtual Mode
65. Which of the following handles user input/output in DOS?
A) BIOS only
B) BIOS and DOS kernel together
C) COMMAND.COM
D) MSDOS.SYS alone
66. Which interrupt is mainly used for DOS system services?
A) INT 09h
B) INT 0Ah
C) INT 21h
D) INT 13h
67. INT 13h in DOS is used for:
A) Keyboard input
B) Disk services
C) File operations
D) Screen display
68. The DOS boot process begins with:
A) COMMAND.COM
B) CONFIG.SYS
C) Boot sector loading IO.SYS
D) MSDOS.SYS execution
69. Which file acts as the kernel of DOS?
A) IO.SYS
B) MSDOS.SYS
C) COMMAND.COM
D) CONFIG.SYS
70. What does FCB stand for in DOS?
A) File Control Buffer
B) File Control Block
C) Fixed Control Base
D) File Command Batch
71. The “PATH” environment variable defines:
A) Disk label name
B) List of directories to search for executables
C) Network address
D) User home folder
72. Which of the following is NOT a valid file attribute in DOS?
A) Archive
B) System
C) Hidden
D) Compressed
73. The command “ATTRIB +H FILE.TXT” makes the file:
A) Read-only
B) Hidden
C) Archived
D) System file
74. To remove the read-only attribute from a file:
A) ATTRIB -H FILE.TXT
B) ATTRIB -R FILE.TXT
C) DELATTR FILE.TXT
D) READON -OFF
75. Which command is used to print a file in DOS?
A) SHOW
B) PRINT
C) TYPE
D) ECHO FILE
76. Which DOS command displays a list of previously executed commands?
A) LOG
B) DOSKEY /HISTORY
C) RECORD
D) LASTCMD
77. DOS was initially designed for which processor family?
A) 8080
B) 8086
C) 80286
D) 68000
78. The DOS kernel loads which file last during boot?
A) IO.SYS
B) COMMAND.COM
C) CONFIG.SYS
D) AUTOEXEC.BAT
79. Which DOS command is used to display help about a command?
A) /HELP
B) ?
C) / ?
D) /INFO
80. Which DOS command checks for logical disk errors?
A) MEM
B) CHKDSK
C) VERIFY
D) FIXDISK
81. The “DIR /W” command:
A) Lists hidden files
B) Displays directory in wide format
C) Shows writable files
D) Displays warnings
82. Which command provides disk space usage?
A) DIR /S
B) CHKDSK /V
C) SPACE /D
D) FILESTAT
83. Which command is used to remove all files in subdirectories too?
A) DEL .
B) DEL /S
C) ERASE /R
D) DELETE /A
84. Which key combination repeats the last command in DOSKEY?
A) F3
B) F2
C) Ctrl + R
D) Alt + ↑
85. The “VERIFY ON” command ensures:
A) Backup creation
B) File writes are verified on disk
C) Checksum calculation
D) Disk optimization
86. Which command loads a program into high memory area?
A) LOAD
B) LOADHIGH (LH)
C) MEMSET
D) EXEC
87. Which memory area in DOS is limited to 640 KB?
A) Conventional Memory
B) Extended Memory
C) Expanded Memory
D) Cache Memory
88. To exit DOS shell or command interpreter:
A) CLOSE
B) EXIT
C) END
D) QUIT
89. The “DEFRAG” utility is used to:
A) Delete bad sectors
B) Rearrange files to optimize disk access
C) Format the drive
D) Clear cache
90. Which DOS command displays or changes the volume label?
A) LABEL /VIEW
B) LABEL
C) VOL /SET
D) DISKNAME
91. Which DOS version first supported memory management utilities?
A) 2.0
B) 3.0
C) 5.0
D) 6.0
92. Which DOS command lists the directories recursively?
A) SHOWDIR
B) DIR /S
C) DIR /R
D) VIEWALL
93. To concatenate two text files into one:
A) COPY FILE1+FILE2 FILE3
B) COPY FILE1.TXT+FILE2.TXT FILE3.TXT
C) JOIN FILE1 FILE2
D) TYPE FILE1 FILE2 > FILE3
94. Which command in DOS can terminate a running batch script?
A) EXIT
B) STOP
C) HALT
D) PAUSE OFF
95. The “FC /B” command compares files in:
A) ASCII mode
B) Binary mode
C) Unicode
D) Fast mode
96. What is the purpose of the “DOSKEY” command?
A) Display command prompt
B) Recall and edit previous commands
C) Run batch files
D) Store environment variables
97. Which DOS command displays all file attributes?
A) SHOWATTR
B) ATTRIB
C) PROPERTY
D) VIEWATTR
98. What does “XCOPY” provide that “COPY” does not?
A) Printing capability
B) Copying directories and subdirectories
C) Appending text
D) File comparison
99. Which of the following is NOT a DOS command?
A) EDIT
B) FORMAT
C) COPY
D) INSTALL
100. DOS cannot handle filenames longer than:
A) 8 characters for name + 3 for extension
B) 10 characters total
C) 6 characters
D) 9 characters