Disk Operating System _Dos — Part 1 MCQs with Explanations

MS stands for Microsoft, DOS is the name of operating system Disk Operating System, 6.22 is the version number that identifies the product.

Ver command displays the version number of Dos. There is no command as Disk. Format command prepares a disk to be used with DOS. Thus Date is the command that lets you to display and/or change the system date.

For a specific file to copy from one disk to another disk, Copy command should be used. Diskcopy copies whole disk into new disk. Time command is to display system time and Rename command just changes the name of a file.

Time command displays and allows you to change system time. TIME only displays the system time and TIME is used to set new time as system time.

Ver is used to display the version number of DOS in use. Fat command does not exist and Chkdsk is to check disk errors and fix it. Thus dividing surface into sectors is done by Format command.

command.com, io.sys and msdos.sys are the essential system files of MS-Dos. Loading these files from disk into memory is known as booting. Booting is the process of preparing your computer to work.

Diskcopy is used to perform track-by-track copy of a disk into another. Copy command copies selected files; chkdsk and format commands are not for copying purpose.

Dir command lists the directory of current location. It includes the files, subdirectories and some other system information. Tree command is used to list the directory structure in tree diagram; CD command to change directory and Copy command to copy a file into another.

Dir/w only displays the file names and extensions excluding file created date/time, file size. Second option dir a: will list the contents of A drive (floppy drive), third dir/s lists current directory and its sub-directories too, dir/b displays bare format, that means, it just makes a list of files, no more information.

* is a wild card character that stands for all any character. When you specify filename.*, it meant filenameshould be specified one but extension can be any. Second option lists only the specified filename.exe and third and fourth commands lists all files with sys extension and specified extension.

dir/b command barely lists the names of files and directories without any other information like size, date, time etc.

Using comma for separating thousand in file size is by default on. You can use dir/-c to remove comma from the listing. /C stands for comma.

First and second options are obviously wrong since specifying filename will list for that filename only. Since we need to list only with .exe extension fourth option is correct. Third option displays all files with sys extension.

The subordinate directory of subdirectory can be accessed through the path sequence pathname\pathname and dir command lists the files of that location.

Tree command lists the directory structure in tree structure and /f switch of tree command includes the filenames in the structure.

Displaying a file which is inside specified directory can be done by specifying a directory name \ andfilename.

MK command and MKDIR both commands are equivalent and can be used to create subdirectories. Dir only lists directory but can't create.

CD and CHDIR commands are equivalent and both used to change current working directory to another one. MKDIR creates a new directory and can't be used to change.

RD command or RMDIR commands can be used to remove a directory if it is empty. Del command and Erase commands are used to delete files not directories. MD creates a new directory and can't remove directory.

In Disk Operating System (DOS), the maximum length of a path name is determined by the underlying file system, typically FAT (File Allocation Table) systems used in older versions of DOS. In FAT systems, the maximum path length consists of the root directory name and sub-directory names. Each component (directory or file name) in the path can be up to 8 characters long, and the separators (backslashes) between directory names also count towards the total path length. The root directory itself can have up to 11 characters, including the drive letter and colon (e.g., "C:"). Each additional directory or file name in the path can be up to 8 characters long. However, the total path length is constrained by the maximum number of characters, which is typically 63 characters in DOS environments. This total includes the root directory, separators, and all directory and file names in the path. Therefore, the correct answer is Option C: 63 characters.

MS-DOS, which stands for Microsoft Disk Operating System, was developed by Microsoft and released in 1984 . It was a command-line operating system that provided a foundation for subsequent versions of Microsoft Windows operating systems. MS-DOS was designed to be used with IBM PC compatible hardware, becoming a key component in the widespread adoption of personal computers in the 1980s and early 1990s. Therefore, the correct answer is Option B: 1984.

In MS-DOS, the maximum length of a command, including any optional parameters, is limited to 127 characters . This includes the command itself and any parameters or options that follow it. MS-DOS commands are entered at the command prompt and are typically short, but they can include various options and parameters to modify their behavior. Therefore, the correct answer is Option C: 127 characters.

In Disk Operating System (DOS), the CHKDSK command was replaced by SCANDISK in version 6.2 . This change occurred to enhance the capabilities of disk checking and repair utilities within DOS. SCANDISK provided improved functionality and reliability over CHKDSK, addressing disk errors and ensuring file system integrity. Therefore, the correct answer is Option B: 6.2.

The CHKDSK command in Disk Operating System (DOS) is used to analyze and diagnose hard disk errors. It checks the file system for errors, verifies disk integrity, and can optionally fix logical file system errors. Therefore, it addresses both Options A and B, which involve analyzing and diagnosing hard disk errors. Option C, "Report the status of files on disk," is not entirely accurate for CHKDSK. Instead, CHKDSK primarily focuses on the integrity and error-checking of the file system rather than reporting the status of individual files. Therefore, the correct answer is Option D: All of the above , considering that CHKDSK is primarily used to analyze and diagnose hard disk errors, which encompasses Options A and B.

During the boot process of a computer running Disk Operating System (DOS), the batch file that is read is typically named Autoexec.bat . This file is automatically executed by DOS during startup and can contain commands that configure system settings, load device drivers, and set environment variables. Option B, "Auto-batch," and Option C, "Autoexecutive.bat," are not standard filenames used during the DOS boot process. Option D, "Auto.bat," while close in name to the correct option, is not the standard filename traditionally used for the batch file executed during boot-up. Therefore, the correct answer is Option A: Autoexec.bat.

In Disk Operating System (DOS) versions 6 and later, the command used for backup is MSBACKUP . MSBACKUP is a utility provided by Microsoft to perform backup operations, allowing users to back up files and directories to another location such as a floppy disk or another hard drive. Option A, "BACKUP," is not a standard DOS command for backup operations in DOS versions 6 and later. Option C, "MSBACKEDUP," is not a valid DOS command. Therefore, the correct answer is Option B: MSBACKUP.

In Disk Operating System (DOS), both Copy and Xcopy commands can be used to copy files or groups of files. However, they differ in their functionalities: Copy is an internal command of DOS, which means it is built into the command interpreter (command.com) and does not require a separate executable file. Xcopy , on the other hand, is an external command of DOS, which means it is implemented as a separate executable file (xcopy.exe). It provides more advanced features compared to the basic Copy command, such as copying subdirectories recursively, copying hidden/system files, and verifying copied files. Therefore, the correct answer is Option D: Both a and b.

The command used to clear the screen and display the operating system prompt on the first line of the display in Disk Operating System (DOS) is cls . Option A, "Cd," is used to change the current directory. Option B, "Md," is used to create a new directory. Option C, "Rename," is used to rename a file or directory. Therefore, the correct answer is Option D: cls.

In Disk Operating System (DOS), the command used to clear the screen is Cls . This command clears the console screen, removing all previous commands and output, and displays the command prompt at the top of the screen. Option B, "Clear," is not a valid DOS command for clearing the screen. It is commonly used in Unix-like systems. Option C, "Clscreen," is not a valid DOS command. Therefore, the correct answer is Option A: Cls.

Internal commands in DOS are those commands that are built into the operating system and do not require an external program or file to be executed. The internal commands that are available in DOS may vary depending on the version of DOS that is being used. Out of the options given, only option C consists of internal commands in DOS: #1 Time: displays or sets the system time. #2 Type: displays the contents of a text file on the screen. #3 Dir: displays a list of files and subdirectories in a directory. Option A consists of two commands, 'Cls' and 'rd label'. 'Cls' is an internal command in DOS that clears the screen. 'rd label' is not an internal command in DOS; it is a command to remove a directory. Option B also consists of three commands, 'Dir', 'ren', and 'sys'. 'Dir' is an internal command in DOS. It displays a list of files and subdirectories in a directory. 'Ren' is also an internal command that is used to rename a file or a directory. 'Sys' is not an internal command in DOS. Option D consists of three commands, 'Del', 'disk copy', and 'label'. 'Del' is an internal command in DOS that is used to delete a file. 'Disk copy' is not an internal command in DOS; it is a command to copy the contents of one floppy disk to another. 'Label' is also an internal command in DOS that is used to create, change or delete the volume label of a disk.

In Disk Operating System (DOS), the command used specifically to copy files is Copy . The Copy command in DOS allows users to copy one or more files from one location to another. Option B, "Diskcopy," is used to copy the entire contents of one floppy disk to another and is not used for copying individual files. Option C, "Type," is used to display the contents of a text file. Therefore, the correct answer is Option A: Copy.

To copy the hidden system files of DOS to another disk, you can use the command Sys . The Sys command in DOS is used to transfer the system files (including hidden and system files) from one disk to another. It allows you to make a disk bootable by transferring the necessary system files. Option A, "Copy," is used to copy files, but it does not specifically handle hidden system files or make a disk bootable with system files. Option B, "Ren," is used to rename files or directories. Option D, "Diskcopy," is used to copy the entire contents of one floppy disk to another, but it does not handle hidden system files specifically. Therefore, the correct answer is Option C: Sys.

In Disk Operating System (DOS), the command used to copy the entire contents of one floppy disk to another is Diskcopy . This command is specifically designed for duplicating the contents of a floppy disk, including both system and user files, to another floppy disk. Option A, "Copy a file," refers to the Copy command, which is used to copy individual files, not entire disks. Option C, "Copy contents of CD-ROM to another," does not apply to Diskcopy, as Diskcopy is specifically for floppy disks, not CD-ROMs. Therefore, the correct answer is Option B: Copy contents of one floppy disk to another.

In Disk Operating System (DOS), the SYS command is used to copy DOS system files to a new disk . This command is typically used to transfer the essential system files required to make a disk bootable with DOS. It copies files such as io.sys, msdos.sys, and command.com to the destination disk, ensuring that it can function as a startup disk. Option B, "Copy DOS configuration files to a new disk," is not correct. The SYS command specifically copies system files, not configuration files. Option C, "Update the DOS system files," is partially correct in the sense that SYS copies the system files to a new disk, but it doesn't update existing files on the current disk. Therefore, the correct answer is Option A: Copy DOS system files to new disk.

To copy a file named temp.doc from drive C: to drive A: in Disk Operating System (DOS), the correct command is Option B: Copy c:\temp.doc a: . This command specifies the source file with its full path (c:\temp.doc) and the destination drive (a:). Option A, "Copy temp.doc to a:," is not a valid DOS command syntax. Option C, "Copy c: a:," does not specify the file name and is not a complete command for copying a specific file. Option D, "Copy temp a: c:," has incorrect syntax and does not specify the full path of the source file. Therefore, the correct answer is Option B: Copy c:\temp.doc a:.

External commands in Disk Operating System (DOS) are commands that are implemented as separate executable files (.exe or .com) stored in a directory specified in the PATH environment variable. They are not built into the command interpreter (command.com). Among the options provided: Option A, "Copy, edit, sys, format," includes commands that are external commands in DOS. Option B, "Edit, sys, chkdsk," includes some external commands but not all listed are external commands. Option C, "Chkdsk, prompt, date," includes some commands that are typically internal commands. Option D, "Sys, ver, vol," includes some commands that are typically internal commands. Therefore, the correct answer is Option A: Copy, edit, sys, format.

In Disk Operating System (DOS), the key combination that can be pressed to quit without saving is Ctrl + C . This key combination sends a termination signal to the running program or command, allowing you to exit without saving changes or stopping the current operation. Option A, "Ctrl + A," does not typically have a special meaning in DOS and is not used for quitting without saving. Option B, "Ctrl + B," and Option D, "Ctrl + D," also do not have specific meanings for quitting without saving in DOS. Therefore, the correct answer is Option C: Ctrl + C.

In Disk Operating System (DOS), the command used to get the current date only is Option A: Date . When you enter "date" at the command prompt in DOS, it displays the current date set on the system. Option B, "Time," is used to display or set the current time, not the date. Option C, "Second," is not a valid DOS command for retrieving the date. Therefore, the correct answer is Option A: Date.

Generally, in Disk Operating System (DOS), the date is entered in the form Option D: MM-DD-YY . This format represents the month (MM), day (DD), and year (YY) separated by dashes. Option A, "DD-YY-MM," is not a standard format used for entering dates in DOS. Option B, "YY-DD-MM," and Option C, "MM-YY-DD," are also not standard formats used for entering dates in DOS. Therefore, the correct answer is Option D: MM-DD-YY.

In Disk Operating System (DOS), the DEL command is used to delete files . When you enter "del filename" at the command prompt in DOS, it deletes the specified file from the current directory. Option B, "Delete directory," is not done with the DEL command in DOS. To delete a directory, the command is typically "rmdir" or "rd" in DOS. Option C, "Delete labels," is not a function of the DEL command in DOS. Option D, "Delete contents of file," is not the primary purpose of the DEL command, which deletes entire files rather than just their contents. Therefore, the correct answer is Option A: Delete files.