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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 693 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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3 questions · 4 marks

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1Multiple choice1 markCompression Swap Remove

Identify the statement that describes lossless compression.

[1 mark]
  • AData is encrypted so that it cannot be read by others
  • BData is permanently removed to make the file smaller
  • CNo data is lost and the original file can be recreated
  • DThe file is split into packets that are sent separately
Mark scheme
  • C No data is lost and the original file can be recreated (1)
  • The only correct answer is C. The correct answer is no data is lost and the original file can be recreated.
  • A is not correct because encryption hides data and does not make the file smaller
  • B is not correct because permanently removing data is lossy compression
  • D is not correct because splitting a file into packets is part of transmission, not compression
Example answers and how they were marked
Full marks1/1

C No data is lost and the original file can be recreated

Why: Correct option (1).

No marks0/1

B Data is permanently removed to make the file smaller

Why: Near miss: this is lossy compression, not lossless, so no mark.

No marks0/1

D The file is split into packets that are sent separately

Why: Misconception that compression is packet switching; no mark.

2Short recall1 markWired Connections Swap Remove

A school's computers are connected to the network using Ethernet cables.

Define the term 'latency'.

[1 mark]
Mark scheme

Award one mark for:

  • A (time) delay between data/a signal being sent and being received (1)

Allow 'the time taken for data to travel from source to destination'

Allow 'the time taken for data to arrive at its destination after it is sent'

Allow 'time lag/time delay'

Do not accept the amount of data that can be transferred per second (this is bandwidth)

Do not accept the speed of the connection/how fast data travels (this is speed, not latency)

Example answers and how they were marked
Full marks1/1

The time delay between data being sent and arriving at its destination.

Why: Gives a delay between data being sent and being received, which is the creditworthy point (1).

No marks0/1

How much data the cable can carry each second.

Why: Describes bandwidth, which the mark scheme says not to accept, so no mark.

No marks0/1

How fast data travels along the Ethernet cable.

Why: Describes speed rather than a delay; the mark scheme does not accept 'how fast data travels', so no mark.

3Short recall2 marksCharacter Sets Swap Remove

ASCII is a character set that uses 7 bits to represent each character.

Give two limitations of 7-bit ASCII when it is used to represent text.

[2 marks]
Mark scheme

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

  • (Only) 128 different characters can be represented / 7 bits give 2^7 = 128 different codes (1)
  • It cannot represent characters from languages other than English / non-English alphabets, e.g. Greek, Chinese (1)
  • It cannot represent accented characters, e.g. é, ñ (1)
  • It cannot represent symbols or emoji that are not in the ASCII character set (1)

Award a maximum of one mark for the last three bullets, as they are all examples of characters that fall outside the 128 ASCII codes.

Allow 'it can only represent 128 characters, so some characters are missing' for the first bullet.

Do not accept 'it uses 7 bits' / 'it only uses 7 bits' on its own, without saying what this limits.

Do not accept 'it can only store a limited amount of text' / 'it can only store short messages', as 7 bits limits the number of characters available, not the length of a message.

Do not accept 'it can only represent the characters in the ASCII character set', as this repeats the question.

Do not accept 'it is old/out of date' or 'it cannot store numbers'.

Example answers and how they were marked
Full marks2/2

Only 128 different characters can be represented, so it cannot store characters from other languages such as Greek.

Why: 128 character limit (1) and characters from other languages (1); two separate creditworthy limitations.

Some marks1/2

It cannot show accented characters like é and it only uses 7 bits.

Why: Accented characters (1); 'only uses 7 bits' is not qualified, so scores 0.

No marks0/2

It only uses 7 bits, so it can only store a small amount of text.

Why: Scores 0: text length is not a limitation of 7-bit ASCII, and 'only uses 7 bits' is unqualified; both Do not accept lines apply.

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