Disk Operating System (DOS) MCQ Questions & Answers | Computer Science

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.