Computer Operating System Questions and Answers

Answer: B

Correct answer: internal fragmentation is increased with small pages

Internal fragmentation is the unused part of the last page of an allocation, so it averages half a page - which means small pages reduce it, and the statement is false. The other three are true: small pages need larger page tables, large pages drag in data that will not be used, and large transfers are more efficient.

Answer: D

Correct answer: Partition hard disk

The order is fixed: the low-level format lays down the tracks and sectors, then FDISK divides the drive into partitions, then each partition is given a file system by a high-level FORMAT, and only then can an operating system be installed.

Answer: B

Correct answer: Booting

Booting is the whole process of bringing a machine up: firmware in ROM runs first, tests the hardware, reads the boot sector from disk, and hands control to the operating system it loads. A cold boot starts from power-off and a warm boot restarts a machine already running, so both are kinds of booting.

Answer: C

Correct answer: COMMAND.COM

COMMAND.COM is the command interpreter: it displays the prompt, reads what is typed, executes the internal commands itself, and loads and runs the external ones. IO.SYS and MSDOS.SYS are the two hidden system files beneath it.

Answer: A

Correct answer: cls

CLS clears the screen and returns the cursor, and with it the prompt, to the top left corner. It is an internal command, so it is always available.

Answer: A

Correct answer: relative organization

In relative organisation the records are numbered from a base of zero, so record \( n \) is found by multiplying \( n \) by the record length - the position is computed rather than looked up. That makes any record reachable in one access, at the price of a fixed record length.

Answer: D

Correct answer: Process Control

A process control system is real-time: it must respond to sensor readings within a deadline set by the plant it controls, since a late correction is useless. MS-DOS, Windows XP and Lynx’s desktop products aim at convenience and throughput, with no guaranteed response time.

Answer: A

Correct answer: virtual memory is used only in multi-user systems

Virtual memory serves a single-user machine just as well - it lets a program larger than physical memory run and isolates processes from one another - so that statement is untrue. The other three are correct: segmentation leaves external fragmentation, paging leaves internal fragmentation, and segments may themselves be paged.

Answer: C

Correct answer: allows only the correct receiver to decode the data

In public key encryption each party has a pair of keys: the public one, which anyone may use to encrypt a message, and the private one, which alone can decrypt it. So anyone can send, but only the intended receiver - the holder of the private key - can read what arrives.

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.