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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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4 questions · 8 marks

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1Multiple choice1 markEmbedded Systems Swap Remove

Modern cars contain many embedded systems.

Identify what the embedded system that controls the cruise control does.

[1 mark]
  • AIt controls the interior lights
  • BIt displays a map for the driver
  • CIt keeps the car at a constant speed
  • DIt sounds an alarm if the car is broken into
Mark scheme
  • C It keeps the car at a constant speed (1)
  • The only correct answer is C. The correct answer is it keeps the car at a constant speed.
  • A is not correct because controlling the interior lights is done by a different embedded system in the car
  • B is not correct because displaying a map for the driver is done by the satellite navigation system
  • D is not correct because sounding an alarm is done by a different embedded system in the car
Example answers and how they were marked
Full marks1/1

C It keeps the car at a constant speed

Why: Correct option: this is the function of the embedded system that controls the cruise control (1).

No marks0/1

B It displays a map for the driver

Why: Near miss: displaying a map is the function of the satellite navigation system, which the mark scheme says is not correct, so no mark.

No marks0/1

A It controls the interior lights

Why: Misconception: the interior lights are controlled by a different embedded system, so no mark.

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 marksLow and High Level Languages Swap Remove

A programmer has written a program in assembly language.

Describe why it is necessary to translate the program into machine code before it can be run.

[2 marks]
Mark scheme

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

  • The processor/CPU can only execute machine code/binary instructions (1) so the assembly instructions must be converted into machine code before the program can run (1)
  • Each assembly instruction/mnemonic matches/corresponds to one machine code instruction (1) so each line must be replaced with the machine code the processor executes (1)
  • The program is written using mnemonics (1) that must be translated into machine code for the processor to carry out the instructions (1)
  • The hardware/processor does not understand assembly language directly (1) so it must be translated into machine code that the processor can execute (1)

Do not accept 'assembly language is a low-level language'.

Do not accept 'it is hard to understand' or 'it is not English'.

Do not accept benefits, such as 'machine code runs faster' or 'the program will run more quickly'.

Do not accept 'an assembler/a translator converts it' on its own, with no reference to the processor only being able to execute machine code/binary.

Do not accept responses about high-level languages or about compilers/interpreters.

Example answers and how they were marked
Full marks2/2

The processor can only execute machine code, so the assembly instructions must be converted into machine code before the program can run.

Why: States what the processor can execute (1) and links it to converting the program's instructions into machine code (1).

Some marks1/2

Each assembly instruction matches one machine code instruction.

Why: Correct point about the one-to-one match (1) but no development saying that this is because the processor only executes machine code.

No marks0/2

Because an assembler translates assembly language into machine code.

Why: Names the translator but gives no reason tied to the processor only being able to execute machine code, so no mark; this is in the 'Do not accept' guidance.

4Calculate3 marksAdding Binary Numbers Swap Remove

Binary patterns can represent numbers.

(a)

Complete the table to show the 8-bit result of the binary addition.

[2 marks]
1286432168421
11011011
11011100
Mark scheme

Award one mark for each correct nibble in the correct order:

  • 1011 (1)
  • 0111 (1)

0 marks if the response is not 8-bit binary.

Ignore a carry shown beyond the eighth bit.

Example answers and how they were marked
Full marks2/2

1011 0111

Why: 219 + 220 = 439, which needs 9 bits; the 8 bits that are kept are both correct (2).

Some marks1/2

0000 0111

Why: Forgets to carry the 1s. The second nibble is correct (1); the first is not.

No marks0/2

1101 1111

Why: Never carries. Neither nibble is correct.

(b)

State the name of the error that occurs when this addition is carried out.

[1 mark]
Mark scheme

Award one mark for:

  • overflow (error) (1)
Example answers and how they were marked
Full marks1/1

Overflow

Why: The result needs more bits than are available (1).

No marks0/1

Underflow

Why: A near miss: the result is too big for 8 bits, not too small.

No marks0/1

A syntax error

Why: A syntax error is a mistake in a program's code, not in arithmetic.

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