Computer Fundamentals Questions and Answers

Answer: B

Correct answer: Syntax errors

A compiler checks the program against the grammar of the language, so it catches syntax errors - a missing semicolon, an unmatched bracket, an undeclared name - and refuses to produce code until they are fixed. A logical error breaks no rule of the language: the program compiles and runs, but computes the wrong thing, and only testing reveals it.

Answer: A

Correct answer: Pulse code modulation

PCM converts an analogue waveform to digital in three steps: the signal is sampled at a fixed rate, each sample is quantised to the nearest of a set of levels, and the level is written as a binary number. Sampling above twice the highest frequency present - the Nyquist rate - allows the original to be reconstructed; telephone speech is sampled at 8 kHz with 8 bits, giving 64 kbps.

Answer: B

Correct answer: Hub

Spyware, malware and viruses are all hostile software. A hub is a piece of networking hardware - a simple device that repeats an incoming signal to every other port - so it is the odd one out.

Answer: D

Correct answer: 256

A byte is eight bits, and each bit can independently be 0 or 1, so the number of distinct patterns is \[ 2^8 = 256 \] - the values 0 to 255 if the byte is read as an unsigned number.

Answer: B

Correct answer: Interrogation

Putting a question to a file from a terminal and receiving the matching records back is interrogation - querying the file rather than updating it. “Interactive” describes the general style of working at a terminal; interrogation is the particular act of asking the file a question.

Answer: C

Correct answer: Encryption

Encryption transforms data with a key so that anyone intercepting it sees only meaningless output, and only a holder of the matching key can recover the original. A bar code and a mnemonic merely re-express data in another notation, with nothing kept secret.

Answer: B

Correct answer: Visual Display Unit

VDU stands for Visual Display Unit - the screen on which the computer’s output is shown, historically a cathode-ray tube and now a flat panel. It is an output device: it displays results but captures nothing.

Answer: B

Correct answer: Small, special-purpose programs

A device driver is a small program that translates the operating system’s general requests into the particular commands one model of device understands, so a new printer or card can be supported by installing its driver rather than by changing the operating system. The innermost part of the operating system is the kernel.

Answer: A

Correct answer: preemptive scheduling

Under preemptive scheduling the operating system may take the processor away from a process that is still perfectly able to run - when its time slice expires or a higher-priority process becomes ready - and give it to another. Non-preemptive scheduling lets a process keep the processor until it blocks or finishes.

Answer: A

Correct answer: Graphical user Interface

GUI is a graphical user interface - windows, icons, menus and a pointer, operated with a mouse or a touch screen. It replaced the command line, where every instruction had to be typed and remembered.