AQA A-Level Computer Science AS Paper 2, June 2025
Every question from AQA A-Level Computer Science AS Paper 2, June 2025 (7516): 13 questions, 75 marks, each with its mark scheme and topic.
- Question 1 4 marks
Identify integers from a list of numbers, define what is meant by an ordinal number, and explain why real numbers are better suited than natural numbers for representing measurements.
4.5 Fundamentals of data representation · 4.5.1 Number systems
- Question 2 11 marks
Perform various binary representation tasks including calculating total byte values, binary-to-decimal conversion, unsigned binary addition, two's complement range, two's complement subtraction, and unsigned fixed-point representation.
4.5 Fundamentals of data representation · 4.5.2 Number bases · 4.5.3 Units of information · 4.5.4 Binary number system
- Question 3 2 marks
Determine the binary ASCII representation of the character 'T' given 'Q', and state a limitation of ASCII overcome by Unicode.
4.5 Fundamentals of data representation · 4.5.5 Information coding systems
- Question 4 4 marks
Explain how sound samples are represented as bit patterns, the role and necessity of a DAC in playing sound, and determine the highest frequency in an analogue sound sampled at 2200 Hz using the Nyquist theorem.
4.5 Fundamentals of data representation · 4.5.6 Representing images, sound and other data
- Question 5 2 marks
Explain why digital files are compressed and determine the run length encoding (RLE) representation for a given sequence of characters.
4.5 Fundamentals of data representation · 4.5.6 Representing images, sound and other data
- Question 6 9 marks
Define computer hardware and software, describe differences between system and application software, state advantages and types of low-level languages, and explain the role of an assembler.
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 7 8 marks
Identify an XOR logic gate, determine the type of parity computed by an XOR circuit, and explain how parity bits are used to detect transmission errors.
4.6 Fundamentals of computer systems · 4.9 Fundamentals of communication and networking · 4.6.4 Logic gates · 4.9.1 Communication
- Question 8 4 marks
Apply De Morgan's law to an expression and draw a logic circuit for a given Boolean expression using only AND, OR, and NOT gates.
4.6 Fundamentals of computer systems · 4.6.4 Logic gates · 4.6.5 Boolean algebra
- Question 9 5 marks
Describe the roles of the MAR and MBR during the fetch stage, and describe what happens during the decode stage of the Fetch-Execute cycle.
4.7 Fundamentals of computer organisation and architecture · 4.7.3 Structure and role of the processor and its components
- Question 10 5 marks
Complete an assembly language instruction using immediate addressing and write an assembly language program to calculate the nth triangular number.
4.7 Fundamentals of computer organisation and architecture · 4.7.3 Structure and role of the processor and its components
- Question 11 6 marks
Describe the principles of operation of a digital camera after light hits the sensor, and explain how solid-state disks store binary data.
4.7 Fundamentals of computer organisation and architecture · 4.7.4 External hardware devices
- Question 12 9 marks
Discuss a range of moral, ethical, legal, and cultural issues raised by the business model and data practices of an online image editing platform.
4.8 Consequences of uses of computing · 4.8.1 Individual (moral), social (ethical), legal and cultural issues and opportunities
- Question 13 6 marks
Answer questions on serial data transmission, bit rate versus baud rate, logical bus over physical star topology, and disabling SSID broadcast.
4.9 Fundamentals of communication and networking · 4.9.1 Communication · 4.9.2 Networking