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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 573 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 · 9 marks

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1Multiple choice1 markCharacter Sets Swap Remove

Characters are encoded using 7-bit ASCII.

Identify the number of different characters that can be represented using 7-bit ASCII.

[1 mark]
  • A64
  • B127
  • C128
  • D256
Mark scheme
  • C 128 (1)
  • The only correct answer is C. The correct answer is 128.
  • A is not correct because 6 bits give only 64 different combinations
  • B is not correct because 127 is the largest 7-bit value, not the number of characters that 7 bits can represent
  • D is not correct because 256 characters need 8 bits, as used by 8-bit extended ASCII
Example answers and how they were marked
Full marks1/1

C 128

Why: Selects the only correct option (1): 7 bits give 2 to the power of 7, which is 128 different characters.

No marks0/1

D 256

Why: Near miss scoring 0: 256 is the number of characters that 8 bits give in extended ASCII, not 7-bit ASCII.

No marks0/1

B 127

Why: Misconception scoring 0, the off-by-one error the examiners' report describes: 127 is the largest 7-bit value, but 7 bits give 128 different characters.

2Short 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.

3Short recall2 marksUnits & Conversion Swap Remove

Data storage is measured in binary multiples.

Define the term bit.

[2 marks]
Mark scheme

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

  • A binary digit (1)
  • Has the value 0 or 1 (1)
  • The smallest unit of data storage (1)
  • A single 0 or 1 (1)

Allow binary digit/binary place value for binary digit

Allow a single binary digit for a single 0 or 1

Do not accept a group of 8 bits/half a nibble of 4 bits, which describe a byte or a nibble

Do not accept a binary number/binary on its own

Example answers and how they were marked
Full marks2/2

A binary digit that can have the value 0 or 1.

Why: A binary digit (1) and has the value 0 or 1 (1).

Some marks1/2

It is the smallest unit of data storage.

Why: Smallest unit of data storage (1), but does not state that it is a binary digit or that it has the value 0 or 1.

No marks0/2

A group of 8 bits.

Why: Describes a byte, not a bit; no creditworthy point and named in the Do not accept line.

4Describe2 marksUtility Software Swap Remove

A hard disk can become fragmented as files are saved and deleted.

Describe how disk defragmentation software improves the performance of a hard disk.

[2 marks]
Mark scheme

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

  • Parts of a file are moved so they are stored together/in consecutive locations (1) so the read/write head has less distance to travel to read the file (1)
  • Files are rearranged so that each file is stored in one block (1) which reduces the time taken to open/load the file (1)
  • Free space on the disk is collected into one area (1) so new files can be saved without becoming fragmented (1)
  • The parts of each fragmented file are put in order (1) so fewer movements of the read/write head are needed to read it (1)

Do not accept responses about compressing files, deleting files or increasing the amount of storage, as these are not what defragmentation software does.

Do not accept 'it makes the disk faster' without saying how the files are changed.

Example answers and how they were marked
Full marks2/2

It moves the parts of a file so they are stored together in consecutive locations (1), so the read/write head does not have to move as far and the file opens more quickly (1).

Why: Linked point (1) and development (1): the file parts are stored together, which reduces read/write head movement.

Some marks1/2

It reorganises the files on the hard disk so that they are stored together.

Why: The point is made (1) but there is no development saying how this improves performance, so the second mark is not awarded.

No marks0/2

It compresses the files so that they take up less space on the disk.

Why: This describes data compression software, which the mark scheme says is not accepted; no creditworthy point is made.

5Calculate2 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 patternShift8-bit binary result
1000 0001Logical 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.

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