Exam-style questions by topic — AQA GCSE Computer Science
One verified question for each of 37 topics. These are written for this specification and checked by MasteryMind. They are not past-paper questions, and they are not from AQA.
Representing algorithms
A student is writing a program to run a school library. Which action best shows decomposition being applied to this problem?
Practise Representing algorithmsEfficiency of algorithms
Two students write different algorithms that both correctly sort a list of names into alphabetical order. What does this show about solving the sorting problem?
Practise Efficiency of algorithmsSearching algorithms
A binary search is run on the sorted list [2, 5, 8, 12, 16, 23, 38] to find the value 23. Which item is compared first?
Practise Searching algorithmsSorting algorithms
A programmer must sort a large, completely unsorted data set and is choosing between bubble sort and merge sort. Which statement gives a correct advantage of merge sort for this situation?
Practise Sorting algorithmsData types
A program reads a postcode such as AB1 2CD from a user and keeps it as text so it can be searched and compared. Which data type should store this value?
Practise Data typesStructured programming and subroutines (procedures and functions)
A local variable is created inside a subroutine. Which statement best describes how long that local variable exists?
Practise Structured programming and subroutines (procedures and functions)Robust and secure programming
A password must be at least 8 characters long. A user enters the password "tiger12", which has 7 characters. What should the program do, and why?
Practise Robust and secure programmingProgramming concepts
A student writes a program with three identifiers: score, MAX_LIVES and calculateAverage. Which option correctly classifies all three?
Practise Programming conceptsArithmetic operations in a programming language
A program calculates 29 MOD 6. What value does this expression produce?
Practise Arithmetic operations in a programming languageRelational operations in a programming language
A program compares two variables, x and y, using the expression x > y. If x is 8 and y is 5, what is the result of this comparison?
Practise Relational operations in a programming languageBoolean operations in a programming language
A program evaluates the expression False OR True. What value does the expression produce?
Practise Boolean operations in a programming languageData structures
A programmer wants to store details of 50 cars using the Car record type. Which approach best uses the record structure to hold all 50 cars?
Practise Data structuresInput/output
A program stores a pupil's name in the variable pupilName and their score in the variable score. Which statement correctly sends both values to the computer display so that the pupil can read them?
Practise Input/outputString handling operations in a programming language
A program has the text "0.5" stored in a variable. Which type of value is produced when this string is converted to a real number?
Practise String handling operations in a programming languageRandom number generation in a programming language
A quiz program must pick one question at random from a list stored in an array with index positions 0 to 9. Which statement correctly picks a random question from the whole list?
Practise Random number generation in a programming languageNumber bases
The decimal number 906 is written using powers of ten. Which expression gives its correct place-value breakdown?
Practise Number basesConverting between number bases
A memory address is stored as the two-digit hexadecimal value FF. What decimal value does this represent?
Practise Converting between number basesUnits of information
Using decimal prefixes (1 kB = 1000 bytes, 1 MB = 1000 kB), which quantity is the largest: 0.5 MB, 400 kB or 450000 bytes?
Practise Units of informationBinary arithmetic
Add the binary numbers 0110 and 0101, giving the answer as a binary number.
Practise Binary arithmeticCharacter encoding
Which description best explains what a character set is?
Practise Character encodingRepresenting images
A designer reduces an image's colour depth from 24 bits per pixel to 8 bits per pixel while keeping the same width and height. What is the effect on the number of colours available and on the file size?
Practise Representing imagesRepresenting sound
A sound is sampled at 44.1 kHz for 3 seconds. How many samples are captured in total?
Practise Representing soundData compression
A file contains the characters with these frequencies: A appears 5 times, B appears 2 times, C appears 1 time and D appears 1 time. A Huffman tree is built by repeatedly combining the two lowest-frequency nodes. Which set of code lengths correctly reflects the resulting Huffman tree?
Practise Data compressionHardware and software
A computer has a processor, memory and a stored photo-editing program. Which statement correctly describes how the hardware and software work together?
Practise Hardware and softwareBoolean logic
Which Boolean operator is represented by the symbol '+' in Boolean algebra?
Practise Boolean logicSoftware classification
A school computer has an operating system, a web browser, a device driver for its printer and a music player. Which statement correctly classifies these programs?
Practise Software classificationClassification of programming languages and translators
A games studio ships a large program to customers and wants fast execution plus protection of its original source code. Which combination of compiler behaviour supports both aims?
Practise Classification of programming languages and translatorsSystems architecture
What best describes cloud storage?
Practise Systems architectureFundamentals of computer networks
A large file is split into packets that may take different routes to the destination. Explain how the internet layer enables these packets to reach the correct destination.
Practise Fundamentals of computer networksFundamentals of cyber security
A school stores students' personal details, including medical information, on its network. Which of the following best describes the main purpose of cyber security in this situation?
Practise Fundamentals of cyber securityCyber security threats
Which of these is an example of removable media that could carry malware into a computer network?
Practise Cyber security threatsSocial engineering
An attacker phones an employee pretending to be from the IT helpdesk and asks for the employee's login details to 'fix a fault'. Which term best describes this attack?
Practise Social engineeringMalicious code (malware)
A company's security team discovers that a piece of malware has infected one workstation and is attempting to spread to other machines on the network by exploiting a vulnerability in a file-sharing protocol. Which type of malware is this?
Practise Malicious code (malware)Methods to detect and prevent cyber security threats
A company configures all employee devices to install operating system updates automatically overnight. Which cyber security risk is this most directly intended to reduce?
Practise Methods to detect and prevent cyber security threatsRelational databases
A library database has a field called OnLoan that records whether each book is currently out on loan. Which data type is most appropriate for OnLoan?
Practise Relational databasesStructured query language (SQL)
A query ends with the clause ORDER BY Surname DESC. In which order will the records be returned?
Practise Structured query language (SQL)Ethical, legal and environmental impacts of digital technology on wider society, including issues of privacy
A student stores their school project in a cloud storage service. Which of these is a privacy risk associated with using cloud storage?
Practise Ethical, legal and environmental impacts of digital technology on wider society, including issues of privacy
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