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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 · 6 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.

2Describe2 marksPeripheral Management Swap Remove

A computer is connected to a new games controller.

Describe the purpose of a device driver.

[2 marks]
Mark scheme

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

  • A device driver is software/program (1) that controls a peripheral device (1)
  • It translates instructions from the operating system (1) into commands/signals the device understands (1)
  • It allows the operating system to communicate with a specific device (1) without needing to know the device's hardware details (1)
  • It is installed for a new device (1) so the operating system can use that device (1)

Do not accept responses that say a device driver is hardware or that it makes a device faster.

Do not award 'it is part of the CPU'.

Example answers and how they were marked
Full marks2/2

A device driver is a program that controls a peripheral device. It translates instructions from the operating system into commands the device understands.

Why: Gives the linked description: software/program (1) that controls a peripheral (1).

Some marks1/2

It translates instructions from the operating system.

Why: Gives the first point (1) but does not develop it into commands/signals the device understands.

No marks0/2

A device driver is a piece of hardware that connects the controller to the computer.

Why: No credit: says a device driver is hardware, which the mark scheme does not accept.

3Calculate3 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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