Which of the following is NOT a necessary condition for a deadlock to occur ?
Answer: D
Correct answer: Preemption
The four Coffman conditions are mutual exclusion, hold and wait, no preemption and circular wait, and all four must hold at once. Preemption is the opposite of the third condition, so allowing it prevents deadlock rather than causing it.
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Using the _____ switch causes FDISK to display the partition status of your hard disk without executing FDISK.
Answer: C
Correct answer: /status
FDISK /STATUS displays the partition table of the hard disk and exits, without entering the interactive menu where partitions can be created or deleted - a safe way to look at the layout.
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Which page replacement algorithm gives the lowest possible page fault rate but cannot be implemented in practice ?
Answer: B
Correct answer: Optimal
The optimal algorithm replaces the page that will not be needed for the longest time ahead, which requires knowing the future reference string. It cannot be implemented, but it serves as the benchmark against which FIFO and LRU are measured.
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In DOS, which of the following keys will bypass the CONFIG.SYS and AUTOEXEC.BAT files?
Answer: B
Correct answer: F5
Pressing F5 as DOS starts skips CONFIG.SYS and AUTOEXEC.BAT entirely, giving a bare system - the standard way of getting in when a driver or a startup line is preventing the machine from booting. F8 instead confirms each line one at a time.
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Which of these is NOT an operating system ?
Answer: D
Correct answer: Oracle
Oracle is a relational database management system, an application that runs on top of an operating system. Linux, Unix and Windows all manage the hardware directly and provide the environment in which such applications execute.
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Thrashing in an operating system refers to ________.
Answer: B
Correct answer: excessive paging activity that leaves little time for useful work
When the pages a process actively needs exceed the frames allotted to it, nearly every reference causes a page fault and the system spends its time swapping rather than computing. Reducing the degree of multiprogramming, or applying the working set model, brings it under control.
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Which command is used to suppress the prompt that asks you to confirm that you want to delete the directory?
Answer: B
Correct answer: DELTREE/F
DELTREE deletes a directory with everything beneath it and normally asks for confirmation first; the /F switch suppresses that prompt so the command can run unattended in a batch file.
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The buffers statement is found in what file?
Answer: A
Correct answer: Config.sys
BUFFERS is a device and memory setting read by DOS as it loads, so it belongs in CONFIG.SYS. AUTOEXEC.BAT runs afterwards, once the system is already configured.
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Which of the following is loaded for CD-ROM support?
Answer: D
Correct answer: MSCDEX.EXE
MSCDEX.EXE - the Microsoft CD-ROM Extensions - gives DOS the ability to treat a CD-ROM as a lettered drive. It works with the hardware-specific driver loaded from CONFIG.SYS, which handles the drive itself while MSCDEX supplies the file system.
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To find out how much memory is available, you could type______.
Answer: B
Correct answer: MEM
MEM reports how memory is being used - conventional, upper, extended and expanded - and how much of each is free. CHKDSK reports on the disk, and MEMMAKER rearranges drivers to free conventional memory rather than reporting on it.
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