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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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5 questions · 8 marks

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1Multiple choice1 markStored Program Computers Swap Remove

Identify the function of the control unit in the fetch-decode-execute cycle.

[1 mark]
  • ADecodes instructions
  • BPerforms arithmetic operations
  • CStores data and instructions
  • DTemporarily stores data being processed
Mark scheme
  • A Decodes instructions (1)
  • The only correct answer is A. The correct answer is Decodes instructions.
  • B is not correct because the arithmetic logic unit performs arithmetic operations
  • C is not correct because main memory stores data and instructions
  • D is not correct because registers temporarily store data being processed
Example answers and how they were marked
Full marks1/1

A Decodes instructions

Why: Correct option: the control unit decodes instructions during the fetch-decode-execute cycle (1).

No marks0/1

C Stores data and instructions

Why: Main memory stores data and instructions, not the control unit; this is a common distractor, so no mark.

No marks0/1

B Performs arithmetic operations

Why: Arithmetic operations are performed by the ALU, not the control unit; a common confusion between CPU components, so no mark.

2Multiple 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]
  • A6
  • B7
  • C8
  • D16
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.

3Short recall2 marksEmbedded Systems Swap Remove

A digital camera contains an embedded system.

Give two functions that the embedded system performs in the digital camera.

[2 marks]
Mark scheme

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

  • Focus the lens/autofocus (1)
  • Control the shutter (speed) (1)
  • Control the flash/decide when the flash is needed (1)
  • Measure the light level to set the exposure/the aperture (1)
  • Stabilise the lens/image stabilisation (1)
  • Zoom the lens in and out (1)
  • Detect a face/smile (1)

Do not accept 'take a photograph'/'take a picture'/'capture an image', as taking photographs is the function of the camera, which is given in the question.

Do not accept 'press the button' as this is an action of the user, not a function performed by the embedded system.

Do not accept vague answers such as 'use the camera', 'turn the camera on and off' or 'make the camera work', which do not name a function that the embedded system performs.

Example answers and how they were marked
Full marks2/2

It focuses the lens and decides when the flash should fire.

Why: Focus the lens (1) and control the flash (1).

Some marks1/2

It controls the zoom and takes a picture when the button is pressed.

Why: Zoom the lens credited (1); 'takes a picture' is not accepted because taking photographs is the function of the camera, which is given in the question, and 'press the button' is the user's action, not a function of the embedded system.

No marks0/2

It takes a picture when the button is pressed and it makes the camera work.

Why: No mark: 'takes a picture' repeats the camera's function given in the question, 'press the button' is an action of the user, and 'makes the camera work' is too vague to name a function.

4Short 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.

5Describe2 marksUtility Software Swap Remove

A computer can lose power while a file is being saved.

Describe what file repair software does.

[2 marks]
Mark scheme

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

  • Attempts to repair/rebuild the corrupted file (1) so that it can be opened by its program again (1)
  • Recovers/retrieves the parts of the file that can still be read (1) so that the user does not lose all of the data in the file (1)
  • Reconstructs the file from data held in other parts of the disk (1) because part of the file/the disk is corrupted (1)
  • Saves a new/repaired copy of the file (1) as some of the data in it may not be recoverable (1)

Do not accept 'it repairs the file' on its own, as this repeats the question.

Do not accept responses about restoring a backup/previous version of the file, as this is backup software.

Do not accept responses about scanning for or removing malware.

Example answers and how they were marked
Full marks2/2

It recovers the parts of the file that can still be read (1) so that the user does not lose everything that was saved in it (1).

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

Some marks1/2

It rebuilds the damaged file from other parts of the disk.

Why: A valid point is made (1) but there is no development of what this achieves, so the second mark is not awarded.

No marks0/2

It restores the last backup of the file so the user gets the data back.

Why: This describes backup software, which the mark scheme does not accept for this question.

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