Edexcel GCSE Computer Science sample questions and answers (1CP2)
Guide overview All 6 topics Sample questions Papers and weighting Look inside Questions and answers
30 sample questions and answers
Taken from every topic of Edexcel GCSE Computer Science, specification 1CP2. The full guide has 680.
Paper 1
Computational Thinking
107 questions in the guide, across 6 subtopics. More from this topic
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Decomposition, abstraction and subprograms
A program models a game of noughts and crosses. Which details of a real game would abstraction remove?
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Abstraction would remove the pen, the paper and the players’ appearance. The model keeps only the 3 × 3 grid, the marks and whose turn it is. -
Decomposition, abstraction and subprograms
Why does using subprograms save a programmer time?
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A subprogram is written once and can be called as many times as needed. The same code does not have to be repeated in several places. -
Algorithms, flowcharts and pseudocode
What is the difference between count-controlled and condition-controlled repetition?
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Count-controlled repetition runs a fixed number of times, known before the loop starts. Condition-controlled repetition keeps going while a condition holds, so the number of repeats may be unknown. -
Algorithms, flowcharts and pseudocode
Why is a string treated as a data structure?
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A string is a sequence of characters, each with its own index. Single characters can be reached in the same way as items in an array. -
Operators and trace tables
What is the value of 7 + 3 × 2, and why?
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The value is 13. Multiplication is carried out before addition, so 3 × 2 = 6 is worked out first.
Paper 1
Data
128 questions in the guide, across 8 subtopics. More from this topic
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Binary, states and unsigned integers
What is the smallest number of bits needed to give a unique code to each of 50 students?
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Six bits are needed, since 2⁶ = 64 codes is enough for 50 students. Five bits give only 32 codes, which is too few. -
Two's complement
Convert −45 to 8-bit two's complement.
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The value −45 is 11010011 in 8-bit two's complement. Positive 45 is 00101101, its inverse is 11010010, and adding 1 gives 11010011. -
Binary addition, overflow and shifts
How can you spot that overflow has happened when adding two 8-bit unsigned numbers?
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Overflow has happened if a carry comes out of the most significant bit. The true answer would need a ninth bit. -
Hexadecimal
Why is hexadecimal a better shorthand for binary than denary?
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Each hex digit lines up with exactly four bits, so conversion is quick and exact. Denary digits do not match any fixed group of bits. -
ASCII and the limits of binary representation
How do the ASCII codes for upper-case and lower-case letters differ?
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Each lower-case letter's code is 32 more than its upper-case partner. The code for a is 97, while the code for A is 65.
Paper 1
Computers
95 questions in the guide, across 6 subtopics. More from this topic
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Von Neumann architecture and the fetch-decode-execute cycle
What are registers?
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Registers are very small, very fast storage locations inside the CPU. Registers hold the instruction, address or data being worked on at that moment. -
Von Neumann architecture and the fetch-decode-execute cycle
What does the control bus carry?
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The control bus carries control signals such as memory read, memory write and clock signals. The signals coordinate the CPU, memory and other components. -
Secondary storage: magnetic, optical and solid state
What are the advantages of magnetic hard disks?
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Magnetic hard disks offer very large capacities at a low cost per gigabyte. Hard disks suit servers and backups that hold large amounts of data. -
Secondary storage: magnetic, optical and solid state
What are the disadvantages of solid state storage?
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Solid state storage costs more per gigabyte than a magnetic hard disk. Each flash cell can only be rewritten a limited number of times. -
Embedded systems
Where is the program of an embedded system usually stored?
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The program is usually stored in read-only memory or flash memory on the chip. The program is kept when power is lost and runs as soon as the device starts.
Paper 1
Networks
92 questions in the guide, across 6 subtopics. More from this topic
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LANs, WANs and the structure of the internet
Give two examples of a WAN.
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The internet is the largest WAN. A bank linking its branches across the country uses a WAN as well. -
LANs, WANs and the structure of the internet
Why was IPv6 introduced to replace IPv4?
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A 32-bit IPv4 address allows only about 4.3 billion addresses, which is too few for every connected device. IPv6 uses 128-bit addresses, giving vastly more. -
Wired and wireless connectivity and network speed
Why does a wireless connection usually have higher latency than a wired one?
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Wireless devices share the same radio channel and must take turns to transmit. Interference can also force data to be sent again. -
Wired and wireless connectivity and network speed
A 300 megabit file downloads in 6 seconds. What is the transmission rate?
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The transmission rate is 50 megabits per second. The rate is found as 300 megabits ÷ 6 seconds = 50 megabits per second. -
Network protocols
What is HTTP used for?
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HTTP is the protocol web browsers use to request web pages from web servers. The server sends the page back to the browser using HTTP.
Paper 1
Issues and Impact
88 questions in the guide, across 6 subtopics. More from this topic
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Environmental impact of digital devices
How does manufacturing digital devices harm the environment?
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Metals such as cobalt, lithium and gold must be mined, which damages land and uses large amounts of water and energy. Factories also release carbon dioxide and other pollution. -
Environmental impact of digital devices
What problems does the disposal of digital devices cause?
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Discarded devices contain toxic materials such as lead, mercury and cadmium. Devices sent to landfill can leak these into soil and water. -
Personal data: privacy, ownership and consent
What is misuse of personal data?
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Misuse is using personal data in a way the person did not agree to or would not expect. Selling data without permission is one example. -
Personal data: privacy, ownership and consent
State three principles of UK data protection law.
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Personal data must be used fairly, lawfully and transparently. Personal data must be collected only for a stated purpose. Personal data must be kept secure. -
Artificial intelligence, machine learning and robotics
Give an example of harm caused by algorithmic bias.
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A recruitment system trained on past hiring decisions could favour the kinds of people hired before. Qualified applicants from other groups would then be rejected unfairly.
Paper 2
Problem Solving with Programming
170 questions in the guide, across 9 subtopics. More from this topic
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Readable code, debugging and testing
Explain why if total = 100: fails in Python.
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A single = assigns a value and cannot be used as a test, so Python reports a syntax error. A comparison needs the double equals sign ==. -
Selection and loops in Python
List the values produced by range(2, 11, 3).
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The values are 2, 5 and 8. The next value would be 11, which is the stop value and is excluded. -
Data types, conversion, variables and constants
Explain why the result of input() must be converted before it is used in arithmetic.
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The input() function always returns a string. The string must be converted with int() or float() before any calculation. -
String handling
Explain why input is often converted to lower case before it is compared.
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A user may type Yes, YES or yes. The lower() method turns all of them into yes, so a single comparison works. -
Lists, two-dimensional lists and records
What is the list after temps = [18, 21, 19], then temps[0] = 22?
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The list becomes [22, 21, 19]. An assignment to an index replaces the item stored there.
Edexcel GCSE Computer Science Active Recall Guide
The other 650 questions, with the answers printed after each section.