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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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2 questions · 3 marks

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1Multiple choice1 markSound Swap Remove

Identify the term used for the number of bits used to record each sample of a sound.

[1 mark]
  • AAmplitude
  • BBit depth
  • CSample interval
  • DSample rate
Mark scheme
  • B Bit depth (1)
  • The only correct answer is B. The correct answer is bit depth.
  • A is not correct because amplitude is the height of the sound wave at the point it is sampled
  • C is not correct because the sample interval is the time between each sample
  • D is not correct because the sample rate is the number of samples taken each second
Example answers and how they were marked
Full marks1/1

B Bit depth

Why: Selects the only correct option (1).

No marks0/1

D Sample rate

Why: Near miss: this is the number of samples taken each second, not the number of bits per sample (0).

No marks0/1

A Amplitude

Why: Typical confusion: amplitude is what is measured at a sample, not the number of bits used to store it (0).

2Describe2 marksImages Swap Remove

A bitmap image of a logo is stored in binary.

Describe how the pixels in the logo are represented in binary, and how the number of bits available for each pixel can limit the image.

[2 marks]
Mark scheme

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

  • Each pixel is a single colour (1) that is stored/given as a binary value (1)
  • Each pixel is represented by a binary value (1) which gives/represents its colour (1)
  • The pixels are stored in order/rows (1) so the binary values can be read back to recreate the image (1)
  • Each pixel uses a fixed number of bits/colour depth (1) so only a limited number of colours can be represented (1)
  • The number of bits available for each pixel is fixed (1) so some colours cannot be stored/shown (1)

Allow '1s and 0s' for binary value.

For the first mark, accept a statement that a pixel is stored/represented by a binary value; do not award the first mark for 'grid of pixels' or 'a pixel is a single colour' alone unless it is linked to a binary value.

Do not accept 'a pixel is a small dot' alone.

Do not accept responses that only describe file size or resolution.

Example answers and how they were marked
Full marks2/2

Each pixel is a single colour and its colour is stored as a binary value. The number of bits for each pixel is fixed, so only a limited number of colours can be represented.

Why: Linked point (1) that each pixel is a single colour and development (1) that its colour is stored as a binary value; the colour-depth limitation is also creditworthy but the answer is capped at 2.

Some marks1/2

Each pixel is stored as a binary value.

Why: Point (1) that each pixel is stored as a binary value, but no linked development about the colour it represents.

No marks0/2

A bitmap image is made of lots of dots called pixels.

Why: No credit: 'a pixel is a small dot' alone is not accepted because it does not link a pixel to a binary value.

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