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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 · 5 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.

2Describe2 marksUser Management Swap Remove

A school laptop is shared by several teachers.

Describe the purpose of giving each teacher their own user account on the laptop.

[2 marks]
Mark scheme

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

  • Each teacher can keep their own files/desktop separate (1) so other teachers cannot see or change their work (1)
  • Each teacher's work is saved under their own account (1) so they can find their files easily when they log in (1)
  • The operating system knows which teacher is logged in (1) so it can apply the right access rights to that person (1)
  • Each teacher can set up their own desktop/settings (1) so the laptop is set up the way they like to work (1)

Do not accept responses about the laptop running faster or having more storage because it has more accounts.

Do not accept 'so they can log in' without saying why having separate accounts helps.

Example answers and how they were marked
Full marks2/2

Each teacher's files are stored separately, so other teachers cannot open or change their work.

Why: Separate files for each account (1) and other teachers kept out of that work (1).

Some marks1/2

So that each teacher has their own files.

Why: First point of separate files per account (1), but no development of what this achieves (0).

No marks0/2

So the laptop runs faster because each teacher has their own account.

Why: Gives speed as a purpose of user accounts, which is not correct for user management; no creditworthy point.

3Describe2 marksTranslators Swap Remove

A high-level program must be translated into machine code before it can be run.

Describe how a compiler and an interpreter differ in when the translated code is executed.

[2 marks]
Mark scheme

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

  • The interpreter executes each line as soon as it has been translated (1) so translation and execution happen together/at the same time (1)
  • The compiler translates the whole program first (1) and the machine code is run later/separately (1)
  • The interpreter translates the code and runs it while the program is running (1) whereas the compiler does not run the code it produces (1)
  • The compiler produces translated code that is executed only after all the translation has finished (1) but the interpreter executes each line immediately (1)

Allow 'translates one line at a time' where it is linked to executing each line immediately.

Do not accept answers that only state that a compiler is faster/an interpreter is slower, without reference to when execution happens.

Do not accept answers that only give object code, error reporting or portability, without reference to when execution happens.

Do not accept the compiler executing the program as it translates it.

Example answers and how they were marked
Full marks2/2

The compiler translates the code first and the program is executed afterwards, but the interpreter executes each line as soon as it has been translated.

Why: Compiler translates the whole program first and it is executed afterwards (1) and interpreter executes each line as soon as it is translated (1).

Some marks1/2

The interpreter executes each line immediately after translating it.

Why: Correct interpreter timing (1); no comparison with when the compiler's translated code is executed.

No marks0/2

The compiler executes the program line by line as it translates it.

Why: Reverses the two translators; a compiler does not execute the program it translates, so no mark.

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