Menu

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.

Build a paper

Topics (none ticked: all of them)
Question types (none ticked: all of them)

Practice paper

4 questions · 7 marks

Pick again
Print
1Multiple choice1 markSound Swap Remove

A sound wave is sampled and the amplitude of each sample is stored using 2 bits.

Identify the number of different amplitude values that can be stored for each sample.

[1 mark]
  • A2
  • B4
  • C8
  • D16
Mark scheme
  • B 4 (1)
  • The only correct answer is B. The correct answer is 4 (2 bits give 2^2 = 4 values).
  • A is not correct because 2 is the number of bits used to store each sample
  • C is not correct because 8 different amplitude values would need 3 bits
  • D is not correct because 16 different amplitude values would need 4 bits
Example answers and how they were marked
Full marks1/1

B 4

Why: Selects the only correct option (1).

No marks0/1

C 8

Why: Near miss: 8 values would need 3 bits, one more than this recording uses (0).

No marks0/1

A 2

Why: Typical misconception: 2 is the number of bits, not the number of amplitude values those bits can store (0).

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.

3Short recall2 marksCompression Swap Remove

Files can be compressed before they are stored.

Define the term lossless compression.

[2 marks]
Mark scheme

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

  • Reduces/makes the size of a file smaller (1)
  • No data is lost/removed (during compression) (1)
  • The original file/data can be recreated/restored exactly (1)

Allow 'the compressed file takes up less storage space' for the first mark.

The second and third bullets are two ways of making the same point: award a maximum of one mark for them, so a response that says no data is lost and that the original file can be restored, but does not say the file is smaller, scores one mark.

Do not accept descriptions of lossy compression, e.g. 'it removes data that is not needed to make the file smaller'.

Ignore reference to download/transmission times, bandwidth and streaming, as these are benefits of compression and not part of the definition.

Example answers and how they were marked
Full marks2/2

Lossless compression reduces the size of a file without permanently removing any data, so the original file can be restored exactly.

Why: Reduces the size of a file (1) and no data is lost, so the original can be restored exactly (1); maximum of two marks reached.

Some marks1/2

It makes a file smaller so it downloads more quickly.

Why: Reduces the size of a file (1); the faster download is ignored as a benefit, not part of the definition.

No marks0/2

It removes data that is not needed to make the file smaller.

Why: Describes lossy compression, which the do-not-accept line rules out, so the mention of making the file smaller is not credited.

4Describe2 marksLow and High Level Languages Swap Remove

A device driver is software that allows the operating system to control a piece of hardware. Device drivers are often written in a low-level programming language.

Describe one reason why a low-level programming language is suitable for writing a device driver.

[2 marks]
Mark scheme

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

  • Instructions can manipulate/control the hardware/memory/registers directly (1) so the driver can control the specific device it is written for (1)
  • The code is written for one specific processor/architecture (1) so it works with the exact hardware it will control (1)
  • The programmer controls exactly how memory/registers are used (1) so the code is efficient and needs little memory, which suits a device that has limited memory (1)
  • Each instruction maps to one machine code instruction (1) so the driver code is small enough to fit in the memory of the device (1)

Extra detail, such as naming the device the driver controls, is not needed to earn the marks.

Do not accept 'it is closer to machine code' on its own: it must be developed to show how this helps the driver, e.g. it can control the hardware directly.

Do not accept 'it is faster/quicker' with no link to the hardware/device, e.g. the device responds quickly.

Do not accept 'it is easier to learn', 'it is easier to debug' or 'it takes less time to write'.

Example answers and how they were marked
Full marks2/2

Low-level instructions can manipulate the hardware and memory directly (1) so the driver can control the specific device it was written for, such as a sound card (1).

Why: Point about direct control of hardware/memory (1) linked to controlling the specific device (1). The named device is extra detail and is not needed.

Some marks1/2

Low-level instructions can manipulate the hardware directly.

Why: Correct point (1) but no linked development saying how this helps the device driver.

No marks0/2

It is closer to machine code so it runs faster than a high-level language.

Why: 'Closer to machine code' is not developed into how this helps the driver, and 'runs faster' is not linked to the hardware/device, so no mark.

Questions by topic

More ways to revise Edexcel GCSE Computer Science (1CP2)

Teachers: build a paper, print it with the mark schemes at the end, and sign your school up to set your classes activities on every topic.

Fetch Decode Explain isn't affiliated with or endorsed by Pearson Edexcel.