Computer Operating System Questions and Answers

Answer: B

Correct answer: linking loader

A linking loader takes the separately compiled object modules, resolves the external references between them, relocates their addresses to the area of memory they are to occupy, and loads the result ready to run - combining linking and loading in one pass.

Answer: D

Correct answer: with the least processor needs

Shortest job first selects the ready process with the smallest expected processor burst. That minimises the average waiting time - provably so - but it needs an estimate of each burst in advance and can starve long jobs indefinitely if short ones keep arriving.

Answer: D

Correct answer: it’s a CD-ROM DOS driver

MSCDEX.EXE is the Microsoft CD-ROM Extensions: loaded from AUTOEXEC.BAT, it gives the CD-ROM a drive letter and supplies the file system for it, working with the hardware driver loaded earlier from CONFIG.SYS.

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.

Answer: B

Correct answer: ATTRIB + r CBT.EXE

ATTRIB +R sets the read-only attribute, after which the file cannot be changed or deleted until the attribute is cleared with ATTRIB -R. RENAME, COPY and MODE do not alter file attributes.

Answer: C

Correct answer: Used for address translation

The page map table holds one entry per virtual page, giving the frame it currently occupies together with its valid, referenced and modified bits. The memory management unit consults it on every reference to turn a virtual address into a physical one.

Answer: C

Correct answer: there is no need for an address i.e. the data is used as an address

Associative or content-addressable memory is searched by content rather than by location: a pattern is presented and every cell compares itself with it simultaneously, returning the matching entry in one cycle. It is what makes a translation lookaside buffer and a cache tag store fast enough to be useful.

Answer: B

Correct answer: FORMAT A: /Q

/Q performs a quick format: it rewrites the file allocation table and root directory but does not re-create the sector structure or scan for bad sectors. It is fast, and it works only on a disk that has already been formatted once.

Answer: A

Correct answer: XCOPY/D : date

XCOPY with the /D:date switch copies only those files whose modification date is on or after the date given, so an incremental copy can be taken without listing the files by hand. Plain COPY has no such switch.

Answer: D

Correct answer: hashing

Hashing computes a storage address directly from the record’s key, so a record can be reached in a single access without consulting an index. Its cost is collisions, when two keys hash to the same address, which must be resolved by chaining or by probing.