1Why do computers primarily use a binary system?
Computers use a binary system because devices are less expensive and complex for binary representation, it's more reliable to represent two values, and electronic signals are easier to maintain in ON/OFF states.
2Define a "bit" and a "byte."
A bit is the basic unit of data (0 or 1), and a byte is 8 bits, commonly used to represent a character and measure memory.
3How many outputs can 'n' bits represent?
'n' bits can represent 2^n outputs.
4List the four main numbering systems used in computing and their respective bases and symbols.
Binary (Base 2: 0,1), Octal (Base 8: 0–7), Decimal (Base 10: 0–9), Hexadecimal (Base 16: 0–9, A–F).
5What is the data processing cycle?
It is the process of turning collected data into useful information via Input, Processing, and Output.
6List four types of data and a relevant standard for each, as used in computers.
Alphanumeric (ASCII, Unicode), Sound (WAV, MP3), Image (JPEG, PNG), Video (MPEG-2, AVI).
7Why are standards necessary for computer data formats?
Standards make data formats convenient, efficient, flexible, appropriate, interoperable, and allow communication and sharing of information.
8Compare and contrast ASCII and Unicode for text representation.
ASCII is a 7-bit (or extended 8-bit) code for English and symbols. Unicode is a 16-bit superset covering global languages and symbols, sharing the first 256 codes with Extended ASCII.
9How are numbers represented with and without signs in a computer?
Unsigned numbers are always positive. Signed numbers use 2's complement (1's complement + 1) to represent positives and negatives.
10Explain the difference between analog and digital signals.
Analog signals are continuous; digital signals are discrete, using binary voltage levels.
11What are Analog-to-Digital Converters (ADCs) and Digital-to-Analog Converters (DACs) used for?
ADCs convert analog signals to digital; DACs convert digital signals back to analog.
12How is sound digitised and what are "sampling rate" and "sample resolution"?
Sound is digitised by sampling the analog wave at intervals. Sampling rate is samples/second (Hz), and sample resolution is bits/sample.
13How are images represented digitally using pixels, resolution, and colour depth?
Images are grids of pixels. Resolution = width × height. Colour depth = bits/pixel; higher values give more colour and quality.
14How are videos represented in a computer, and what is the role of codecs?
Videos are sequences of image frames. Frame rate affects smoothness. Codecs compress/decompress video to reduce file size while keeping quality.