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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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3 questions · 5 marks

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1Multiple 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.

2Short recall2 marksFetch Decode Execute Cycle Swap Remove

Von Neumann architecture uses the stored program concept.

Define the term stored program concept.

[2 marks]
Mark scheme

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

  • Instructions/programs are held/stored in main memory (RAM) (1)
  • The data the program uses is stored in the same memory as the instructions (1)
  • Instructions are fetched (one at a time) from main memory by the CPU (1)
  • Instructions (fetched from main memory) are decoded and executed (1)

Allow 'memory' for main memory/RAM.

Do not award two marks for a single statement that only says the program/instructions are stored in memory.

Do not accept answers that state the program is stored in secondary storage (such as a hard disk).

Example answers and how they were marked
Full marks2/2

The program instructions and the data it uses are both held in main memory, and the CPU fetches each instruction from main memory in turn to decode and execute it.

Why: Instructions/programs are held/stored in main memory (RAM) (1) and the data the program uses is stored in the same memory as the instructions (1). The fetching and executing points are also present but the maximum is two marks.

Some marks1/2

The instructions of a program are stored in main memory.

Why: Instructions/programs are held/stored in main memory (RAM) (1). Only one part of the definition is given, so one mark.

No marks0/2

The program is kept on the hard disk and is loaded when it is needed.

Why: The answer places the program in secondary storage, which the mark scheme says not to accept, so no creditworthy point is given.

3Describe2 marksTranslators Swap Remove

High-level code can be translated by a compiler or by an interpreter.

Describe how a compiler translates high-level code differently from an interpreter.

[2 marks]
Mark scheme

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

  • The compiler translates the whole program/complete source code in one go (1) whereas the interpreter translates one line/statement at a time (1)
  • The compiler translates all of the source code before any of it is run/executed (1) but the interpreter translates each line/statement as it reads it (1)
  • The interpreter translates one line/statement at a time (1) and the compiler translates the whole program/source code together (1)

Accept the compiler point and the interpreter point in either order.

Do not accept responses about object code/executable files, when the translated code is executed, how errors are reported, or speed/memory use.

Do not accept 'the interpreter executes/runs each line' on its own, without saying that it translates one line/statement at a time.

Example answers and how they were marked
Full marks2/2

A compiler translates the whole program in one go, while an interpreter translates one line at a time.

Why: Whole program translated in one go (1) and interpreter translates one line at a time (1).

Some marks1/2

A compiler translates the whole program in one go.

Why: Whole program translated in one go (1); no linked point about the interpreter translating a line at a time.

No marks0/2

A compiler produces an executable file, but an interpreter does not.

Why: Describes the output, not the amount translated at a time; object code/executable files are not accepted.

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