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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 604 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.

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4 questions · 7 marks

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1Multiple choice1 markFetch Decode Execute Cycle Swap Remove

Identify the CPU component that decodes instructions during the fetch-decode-execute cycle.

[1 mark]
  • AArithmetic logic unit
  • BControl unit
  • CMain memory
  • DRegister
Mark scheme
  • B Control unit (1)
  • The only correct answer is B. The correct answer is control unit.
  • A is not correct because the arithmetic logic unit performs arithmetic and logical operations, not decoding
  • C is not correct because main memory stores instructions and data, not decoding
  • D is not correct because a register holds data or addresses temporarily, not decoding
Example answers and how they were marked
Full marks1/1

B Control unit

Why: Correct option: the control unit decodes instructions (1).

No marks0/1

D Register

Why: Near-miss: a register holds data or addresses temporarily, it does not decode instructions (0).

No marks0/1

A Arithmetic logic unit

Why: Misconception: the arithmetic logic unit performs arithmetic and logical operations; it does not decode (0).

2Short recall2 marksCompression Swap Remove

Files can be compressed before they are stored.

Define the term lossless compression.

[2 marks]
Mark scheme

Award one mark for any of the following up to a maximum of two marks:

  • Reduces/makes the size of a file smaller (1)
  • No data is lost/removed (during compression) (1)
  • The original file/data can be recreated/restored exactly (1)

Allow 'the compressed file takes up less storage space' for the first mark.

The second and third bullets are two ways of making the same point: award a maximum of one mark for them, so a response that says no data is lost and that the original file can be restored, but does not say the file is smaller, scores one mark.

Do not accept descriptions of lossy compression, e.g. 'it removes data that is not needed to make the file smaller'.

Ignore reference to download/transmission times, bandwidth and streaming, as these are benefits of compression and not part of the definition.

Example answers and how they were marked
Full marks2/2

Lossless compression reduces the size of a file without permanently removing any data, so the original file can be restored exactly.

Why: Reduces the size of a file (1) and no data is lost, so the original can be restored exactly (1); maximum of two marks reached.

Some marks1/2

It makes a file smaller so it downloads more quickly.

Why: Reduces the size of a file (1); the faster download is ignored as a benefit, not part of the definition.

No marks0/2

It removes data that is not needed to make the file smaller.

Why: Describes lossy compression, which the do-not-accept line rules out, so the mention of making the file smaller is not credited.

3Describe2 marksTranslators Swap Remove

A compiler and an interpreter both translate source code.

Describe one difference between what a compiler produces and what an interpreter produces.

[2 marks]
Mark scheme

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

  • A compiler produces object code/machine code/an executable (file) (1) whereas an interpreter produces no object code/translated file (1)
  • A compiler produces a machine code file (1) that can be run on its own/without the compiler/translator being present (1)
  • An interpreter produces no object code/file (1) because it translates and executes each line instead of saving translated code (1)
  • The compiler's output can be saved/stored (1) and run again later, while interpreted code has to be translated again each time it is run (1)

Allow binary for machine code.

Allow executable/an executable for object code.

Do not accept responses about translating the whole program, reporting errors or the speed of execution.

Do not accept 'the interpreter translates/executes one line at a time' on its own: this is how it translates, not what it produces. It earns the development only when linked to no object code/translated file being produced.

Do not accept the interpreter producing object code/an executable.

Example answers and how they were marked
Full marks2/2

A compiler produces object code, which is saved as a file, whereas an interpreter does not produce a file because it translates and executes each line.

Why: Compiler produces object code (1) contrasted with the interpreter producing no object code/translated file (1).

Some marks1/2

The compiler produces machine code.

Why: Machine code/object code produced (1); there is no contrast with the interpreter, so the development is not earned.

No marks0/2

The interpreter produces object code for each line it translates.

Why: Reverses the translators' outputs: the interpreter produces no object code, so nothing is creditworthy.

4Explain2 marksProtocols & Layers Swap Remove

Email protocols are used when an email is sent and received.

Explain the role of SMTP when an email is sent.

[2 marks]
Mark scheme

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

  • Sends outgoing email from the client to the mail server (1) so it can be forwarded/relayed to the recipient's mail server (1)
  • Transfers email between mail servers (1) so it reaches the destination server (1)
  • Pushes/sends the email message (1) because it handles outgoing mail while POP3/IMAP handle incoming mail (1)

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

Do not accept receiving/downloading email or storing email on the server, which is POP3/IMAP.

Example answers and how they were marked
Full marks2/2

SMTP sends the email from the sender's computer to the mail server (1) so it can be forwarded on to the recipient's mail server (1).

Why: Linked point (1) and reason (1): sends to the mail server so it can be forwarded.

Some marks1/2

SMTP is used to send emails (1).

Why: Role (1) identified, but no linked reason or expansion of what sending involves.

No marks0/2

SMTP downloads the email to the recipient's device (0) so they can read it.

Why: Downloading email is the role of POP3/IMAP, not SMTP, so no credit is given.

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