Edexcel GCSE Computer Science (1CP2) exam questions

Build a practice paper from 514 exam-style questions, each with its mark scheme and example answers. Print it, or answer it on paper and then open the mark schemes. Or browse the questions by topic.

Practice paper

7 questions · 15 marks

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1Multiple choice1 markCharacter Sets Swap Remove

ASCII is a character set used for representing text.

Identify the number of bits used to encode each character in ASCII.

[1 mark]

Mark scheme

B 7 (1)
The only correct answer is B. The correct answer is 7 bits.
A is not correct because 6 bits give only 64 different characters
C is not correct because 8 bits are used by extended ASCII to give 256 characters
D is not correct because 16 bits give 65 536 different characters, which is far more than the 128 in ASCII

Example answers and how they were marked

Full marks1/1

B 7

Why: B is the only correct answer: each ASCII character is encoded using 7 bits (1).

No marks0/1

C 8

Why: Near miss scoring 0: 8 bits is extended ASCII, and the scheme's C line says extended ASCII, not ASCII, is not the answer.

No marks0/1

A 6

Why: Misconception scoring 0: 6 bits give only 64 different characters, so it cannot be ASCII.

2Short recall1 markSecondary Memory Swap Remove

Data is stored on optical discs as pits and lands.

Name the component in an optical disc drive that reads this data.

[1 mark]

Mark scheme

Award one mark for:

Laser (1)

Allow laser beam

Do not accept read/write head

Do not accept pits

Do not accept lands

Do not accept reflective surface

Do not accept magnet/magnetic

Example answers and how they were marked

Full marks1/1

Laser

Why: Laser is the creditworthy answer (1).

No marks0/1

A read/write head

Why: Read/write head is not accepted by the mark scheme; it reads magnetic media, not optical discs, so no marks are awarded.

No marks0/1

Pits and lands

Why: Pits and lands are what the laser reads, not the component that reads the data, so the mark scheme does not accept them.

3Short recall1 markUnits & Conversion Swap Remove

A file has a size of 2 kibibytes.

State the number of bytes in the file.

[1 mark]

Mark scheme

Award one mark for:

2048 (1)
2 × 1024 (1)
2^11 (1)

Allow 2048 bytes.

Do not accept 2000, which is the number of bytes in two decimal kilobytes.

Do not accept 1024, which is the number of bytes in one kibibyte.

Do not accept 16, which is the number of bits in two bytes.

Example answers and how they were marked

Full marks1/1

2048

Why: 2048 is 2 × 1024, the number of bytes in 2 kibibytes (1).

No marks0/1

2000

Why: 2000 uses the decimal kilobyte, not the binary kibibyte; the mark scheme does not accept it.

No marks0/1

Why: 16 is the number of bits in two bytes, confusing bits with bytes; the mark scheme does not accept it.

4Describe2 marksUtility Software Swap Remove

A student has a large number of photographs stored on a computer.

Describe the purpose of data compression software.

[2 marks]

Mark scheme

Award up to two marks for a linked description such as:

Makes a file/files smaller (1) so less storage space is needed on the disk (1)
Reduces the size of the data (1) so it takes less time to upload/download/transfer the file (1)
Compresses files/folders into a single file (1) so an attachment is under the size limit for email (1)
Reduces the size of the files (1) so more of them fit onto a storage device/backup media (1)

Do not accept 'it compresses the files' on its own, as this repeats the question.

Do not accept responses about protecting files from malware/viruses or about deleting files.

Example answers and how they were marked

Full marks2/2

It makes the files smaller (1) so that they use less storage space on the computer and more of them fit on the disk (1).

Why: The point (1) and a linked development giving the benefit (1).

Some marks1/2

It makes files smaller.

Why: This is the point (1) but there is no development of what the smaller size leads to, so only one mark.

No marks0/2

It protects the files from viruses so that they cannot be damaged.

Why: This describes anti-malware software, which the mark scheme does not accept; no creditworthy point is made.

5Explain2 marksProtocols & Layers Swap Remove

Two computers exchange data over a network.

Explain why network protocols are needed for the two computers to communicate.

[2 marks]

Mark scheme

Award up to two marks for a linked explanation such as:

Devices (can) understand/interpret the data they receive (1) because they follow the same set of rules for communication (1)
Data is sent in an agreed format/structure (1) so the receiving device can interpret/understand it correctly (1)
Devices (can) connect/communicate successfully (1) because they agree how the data is transmitted, such as the type of signal used (1)
Errors (can) be detected/handled (1) because both devices follow the same rules for checking the data (1)

For both marks, the expansion must follow/associate with the statement.

Do not accept 'so devices can talk/communicate with each other' or 'so they can understand each other' without saying they follow the same rules/agreed format.

Do not accept an answer that only states protocols are a set of rules, without saying what this allows (e.g. the data can be understood/interpreted).

Do not accept a faster connection/speed as a reason why protocols are needed.

Do not accept naming a protocol (e.g. TCP/IP, HTTP, Wi-Fi) without an explanation of why it is needed.

Do not accept a description of what a protocol does (e.g. 'TCP splits data into packets') without saying why this is needed.

Example answers and how they were marked

Full marks2/2

Devices can understand the data they receive (1) because they follow the same set of rules for communication (1).

Why: Linked point (1) and reason (1): following the same rules is what lets the devices understand the data.

Some marks1/2

Data is sent in an agreed format (1).

Why: Point (1) identified, but no linked reason saying what the agreed format achieves.

No marks0/2

Protocols are needed so the connection is faster (0) because more data can be sent at once.

Why: Speed is not a reason protocols are needed, so there is no creditworthy point or linked reason.

6Calculate2 marksBinary Shifts Swap Remove

Computers manipulate binary patterns.

Complete the table with the result of applying the shift to the binary pattern.

[2 marks]

Binary pattern	Shift	8-bit binary result
1000 0001	Logical shift right by 1

Mark scheme

Award one mark for each correct nibble in the correct order:

0100 (1)
0000 (1)

0 marks if the response is not 8-bit binary.

Example answers and how they were marked

Full marks2/2

0100 0000

Why: Every bit moves 1 place right, with 0s in from the left: both nibbles are correct (2).

Some marks1/2

0100 0001

Why: A slip in the last bit. The first nibble is correct (1); the second is not.

No marks0/2

0000 0010

Why: Shifts the bits the wrong way. Neither nibble is correct.

7Discuss6 marksUser Management Swap Remove

A school library has 24 computers that are shared by students and teachers throughout the day. Each computer runs an operating system. The school wants users' work to be kept private and the computers to be used only by authorised people.

Discuss how the operating system's user management features can be used to share the computers securely.

Your answer should include:

user accounts
authentication
the benefits for the school.

[6 marks]

Mark scheme

Indicative content

User accounts

Each student and teacher should have their own user account, so the operating system can identify the person who is logged on.
The operating system keeps a record of all valid users on the computer, so unknown users are not allowed to log in.
A separate home area or folder can be created for each account, so a student's saved work is kept apart from other users' work.
An account can be disabled when a student leaves the school, so they can no longer access the computers.

Authentication

A username and password can be required at login, so only users with the correct details can use the computer.
The operating system checks the entered password against the stored password for that account before allowing access.
Users should be encouraged to choose a strong password, which makes it harder for someone else to guess and log in.
The operating system can lock an account after several failed login attempts, which reduces the chance of someone trying passwords repeatedly.

Benefits for the school

Many students can share the same computers because each person's files are kept separate.
Work is less likely to be deleted or changed by another student, because users only see their own files.
The school can see which account was used on a computer, so misuse can be traced to a user.
Teachers can be confident that only authorised people can use the library computers.
The school does not need a separate computer for every student, so it saves money.

Levels

Level 0 (0 marks): No rewardable content.
Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Level 3 responses must cover both user accounts and authentication, and apply them to the school library.

Do not accept general operating system functions such as file management or process management unless they are explicitly linked to managing users.

Example answers and how they were marked

Full marks6/6

Each student and teacher should have their own user account with a username and password. When someone logs in, the operating system checks the password against the one stored for that account, so only authorised people can use the computer. Each account can have its own home folder, so a student's work is kept private and another student cannot open or delete it. If a student leaves the school, their account can be disabled so they cannot log in again. This lets the school share a smaller number of computers safely, as each user's work stays separate and any misuse can be traced to the logged-in account.

Why: Level 3. It explains user accounts, authentication and benefits, with sustained links to sharing computers in the school library.

Some marks4/6

Every user should have a username and password. The operating system checks the password so that people who are not allowed cannot log in. Each user should also have their own area to save files so they do not delete other people's work.

Why: Level 2. Basic accounts and authentication points are made and linked, but the benefits to the school are only briefly applied and not developed.

No marks0/6

The operating system manages the users by looking after the files in folders and by making sure the printer works for everyone. It also keeps the computer running quickly when lots of students use it.

Why: Level 0. These are general operating system functions such as file management and peripheral management, not user management, so no creditworthy point is made.

Edexcel GCSE Computer Science (1CP2) Exam Questions

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Questions by topic

2.1 Binary

2.2 Data representation

2.3 Data storage and compression

3.1 Hardware

3.2 Software

3.3 Programming languages

4.1 Networks

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