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EnglandComputer Science

Component 2: Computer Architecture, Data, Communication and Applications

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is data made smaller, kept secret, and checked for errors during storage and transmission?

Compression, encryption and error checking: lossy and lossless compression (run-length encoding and dictionary methods), symmetric and asymmetric encryption, and error-detection methods (parity, checksums and check digits).
An Eduqas Component 2 answer on compression, encryption and error checking: lossy versus lossless compression with run-length and dictionary methods, symmetric and asymmetric encryption, and error-detection methods including parity, checksums and check digits.
14 min answer →

How is data transmitted across networks, and what do protocols and the TCP/IP stack do?

Data transmission: serial and parallel transmission, packet switching and the structure of a packet, network protocols and the layers of the TCP/IP stack, and the role of standards in communication.
An Eduqas Component 2 answer on data transmission: serial versus parallel transmission with their trade-offs, packet switching and packet structure, the role of network protocols, and the four layers of the TCP/IP stack.
13 min answer →

How is data organised in files and relational databases, and how do normalisation and SQL keep it consistent and queryable?

Organisation and structure of data: files, records and fields with key fields and file access methods, relational databases with primary and foreign keys, normalisation to third normal form, and SQL for querying and manipulating data.
An Eduqas Component 2 answer on the organisation and structure of data: files, records and fields with key fields and access methods, relational databases with primary and foreign keys, normalisation to third normal form, and writing SQL queries.
14 min answer →

How are real numbers stored in floating-point form, and what does normalisation achieve?

Floating-point representation: storing a real number as a mantissa and an exponent in two's complement, evaluating a stored floating-point value, normalising a mantissa, and the trade-off between range and precision.
An Eduqas Component 2 answer on floating-point representation: storing a real number as a two's complement mantissa and exponent, evaluating a stored floating-point value, normalising a mantissa, and the trade-off between range and precision.
14 min answer →

How are numbers represented in binary and hexadecimal, including negatives, and how is binary arithmetic performed?

Data representation of numbers: converting between binary, denary and hexadecimal, representing negative numbers with sign and magnitude and two's complement, binary addition and subtraction, and detecting overflow.
An Eduqas Component 2 answer on number representation: converting between binary, denary and hexadecimal, representing negative numbers with sign and magnitude and two's complement, binary addition and subtraction, and detecting overflow.
14 min answer →

How are text, images and sound represented as binary, and what determines the file size and quality?

Representing text, images and sound: character sets (ASCII and Unicode), bitmap images with resolution, colour depth and the file-size calculation, and sampled sound with sample rate, bit depth and the file-size calculation.
An Eduqas Component 2 answer on representing text, images and sound: the ASCII and Unicode character sets, bitmap images with resolution and colour depth and the file-size calculation, and sampled sound with sample rate and bit depth and the file-size calculation.
14 min answer →