Computer Operating System Questions and Answers

Answer: B

Correct answer: manage resources

The processor, memory, files and devices are all resources that competing programs want at once, and the operating system’s primary job is to manage them - allocating, protecting and reclaiming them. Utilities and a friendly interface are things it also provides, but they rest on that management.

Answer: A

Correct answer: Module strength

Module strength - cohesion - measures how closely the elements within a module belong together, and the strongest form, functional cohesion, is the goal of a good design. A module that does one clearly stated thing is easy to name, test, reuse and change.

Answer: D

Correct answer: All of the above

The operating system manages every resource of the machine: memory, deciding where each program sits and protecting one from another; the processor, scheduling which process runs; and the disks and other devices, driving them and arbitrating between the programs that want them.

Answer: D

Correct answer: make the most efficient use of the hardware

The processor, memory and devices are expensive and idle time is waste, so the operating system exists above all to keep them busy and shared fairly - scheduling work, overlapping computation with input and output, and reclaiming resources promptly. Making the machine convenient to use is its other goal, achieved through the interfaces it provides.

Answer: D

Correct answer: None of the above

Pseudocode is not a programming language at all: it is a notation for writing an algorithm in a mixture of structured English and code-like constructs, so the logic can be set out and reviewed. No compiler accepts it, and it must be rewritten in a real language before it can run.

Answer: B

Correct answer: GOTO

Structured programming builds a program from sequence, selection and iteration, each with one entry and one exit, and forbids the GOTO, whose arbitrary jumps destroy that property and make the flow impossible to follow. IF-THEN-ELSE, WHILE-DO and DO-WHILE are the permitted constructs.

Answer: D

Correct answer: multitasking

Running more than one program at a time requires multitasking: the system must hold several programs, keep the state of each, and switch the processor between them quickly enough that all appear to advance together. Virtual memory helps by letting them all be resident, but it is the switching that makes concurrency.

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: C

Correct answer: FORMAT A: /S

FORMAT A: /S formats the diskette and then copies the system files onto it, so the disk is left bootable in a single command. SYS A: transfers the system files but only to a disk that is already formatted.

Answer: C

Correct answer: RESTORE

Files written by the DOS BACKUP command are held in a special packed form, so an ordinary COPY cannot retrieve them; only the matching RESTORE command can unpack them back to the disk.