AQA A-Level Computer Science Paper 2, June 2025
Every question from AQA A-Level Computer Science Paper 2, June 2025 (7517): 14 questions, 100 marks, each with its mark scheme and topic.
- Question 1 8 marks
Identify software classifications in a hierarchy diagram, describe functions of an operating system, and describe advantages of high-level programming languages.
4.6 Fundamentals of computer systems · 4.6.1 Hardware and software · 4.6.2 Classification of programming languages · 4.6.3 Types of program translator
- Question 2 8 marks
Calculate sound sample resolution from file size and sampling parameters, describe ADC operation, explain inaccuracy in digital sound recording, and explain why MIDI uses less storage.
4.5 Fundamentals of data representation · 4.5.3 Units of information · 4.5.6 Representing images, sound and other data
- Question 3 8 marks
Describe the principles of operation of an optical disk including representation and reading of data, and state two reasons why most modern computers lack an optical drive.
4.7 Fundamentals of computer organisation and architecture · 4.7.4 External hardware devices
- Question 4 3 marks
Explain why it is difficult to write and enforce laws relating to the use of computers.
4.8 Consequences of uses of computing · 4.8.1 Individual (moral), social (ethical), legal and cultural issues and opportunities
- Question 5 3 marks
Explain why a client-server network would be more suitable for use in a school than a peer-to-peer network.
4.9 Fundamentals of communication and networking · 4.9.2 Networking
- Question 6 12 marks
Answer questions on a relational database design for school merits, including key constraints, entity-relationship diagrams, SQL INSERT and SELECT queries, and concurrency issues.
4.10 Fundamentals of databases · 4.10.1 Conceptual data models and entity relationship modelling · 4.10.2 Relational databases · 4.10.4 Structured Query Language (SQL) · 4.10.5 Client server databases
- Question 7 10 marks
State the stored program concept, describe the roles of three processor components (control unit, general purpose registers, status register), and determine register capacity and two's complement range from a 32-bit machine code instruction format.
4.7 Fundamentals of computer organisation and architecture · 4.5 Fundamentals of data representation · 4.7.2 The stored program concept · 4.7.3 Structure and role of the processor and its components · 4.5.4 Binary number system
- Question 8 12 marks
Explain IPv4 address exhaustion, how IPv6 solves it, the difference between public and private IP addresses, and how NAT and DHCP mitigate the address shortage.
4.9 Fundamentals of communication and networking · 4.9.4 The Transmission Control Protocol/Internet Protocol (TCP/IP) protocol
- Question 9 7 marks
Complete a truth table for an ASCII-decoding logic circuit, deduce the purpose of its outputs, and identify the correct Boolean expression for output Q1.
4.5 Fundamentals of data representation · 4.6 Fundamentals of computer systems · 4.5.5 Information coding systems · 4.6.4 Logic gates
- Question 10 4 marks
State two reasons why data is compressed, and explain why run length encoding (RLE) is more suitable for compressing images while dictionary-based compression is better suited for text.
4.5 Fundamentals of data representation · 4.5.6 Representing images, sound and other data
- Question 11 6 marks
Analyze a functional recursive Fibonacci function, determine its properties and type, explain its computational inefficiency, and describe partial function application.
4.1 Fundamentals of programming · 4.4 Theory of computation · 4.12 Fundamentals of functional programming · 4.1.1 Programming · 4.4.4 Classification of algorithms · 4.12.1 Functional programming paradigm · 4.12.2 Writing functional programs
- Question 12 9 marks
Identify normalised floating point values, state reasons for normalisation, convert between two's complement floating point and decimal, and calculate relative error.
4.5 Fundamentals of data representation · 4.5.4 Binary number system
- Question 13 4 marks
Simplify the Boolean expression overline(A.B + NOT(A).C + B.C + NOT(B).A) using the rules of Boolean algebra, showing all working.
4.6 Fundamentals of computer systems · 4.6.5 Boolean algebra
- Question 14 6 marks
Explain the purpose of sections 2 to 6 of an assembly language program controlling a robot's motors and sensors via an 8-bit memory-mapped I/O location.
4.7 Fundamentals of computer organisation and architecture · 4.4 Theory of computation · 4.1 Fundamentals of programming · 4.7.3 Structure and role of the processor and its components · 4.4.1 Abstraction and automation · 4.1.1 Programming