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 · 10 marks

Pick again
Print
1Multiple choice1 markCharacter Sets Swap Remove

Characters are encoded using 7-bit ASCII.

Identify the number of different characters that can be represented using 7-bit ASCII.

[1 mark]
  • A64
  • B127
  • C128
  • D256
Mark scheme
  • C 128 (1)
  • The only correct answer is C. The correct answer is 128.
  • A is not correct because 6 bits give only 64 different combinations
  • B is not correct because 127 is the largest 7-bit value, not the number of characters that 7 bits can represent
  • D is not correct because 256 characters need 8 bits, as used by 8-bit extended ASCII
Example answers and how they were marked
Full marks1/1

C 128

Why: Selects the only correct option (1): 7 bits give 2 to the power of 7, which is 128 different characters.

No marks0/1

D 256

Why: Near miss scoring 0: 256 is the number of characters that 8 bits give in extended ASCII, not 7-bit ASCII.

No marks0/1

B 127

Why: Misconception scoring 0, the off-by-one error the examiners' report describes: 127 is the largest 7-bit value, but 7 bits give 128 different characters.

2Short recall1 markEmbedded Systems Swap Remove

A ticket machine only performs the tasks needed to sell tickets.

State the name of this type of computer system.

[1 mark]
Mark scheme

Award one mark for:

  • Embedded (computer) system (1)

Allow embedded computer/embedded device.

Allow dedicated (computer) system.

Do not accept microcontroller/microprocessor controlled system.

Do not accept general purpose computer/PC/laptop.

Example answers and how they were marked
Full marks1/1

An embedded system.

Why: Correct name of the type of computer system (1).

No marks0/1

A microcontroller.

Why: Near miss: a microcontroller is a component inside an embedded system, not the name of the type of system, so the 'Do not accept' line applies and it scores nothing.

No marks0/1

A general purpose computer.

Why: Misconception: the stem states the system only performs the tasks needed to sell tickets, so 'Do not accept general purpose computer' applies and it scores nothing.

3Describe2 marksUtility Software Swap Remove

A student has a large number of photographs stored on a computer.

Describe the purpose of data compression software.

[2 marks]
Mark scheme

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

  • Makes a file/files smaller (1) so less storage space is needed on the disk (1)
  • Reduces the size of the data (1) so it takes less time to upload/download/transfer the file (1)
  • Compresses files/folders into a single file (1) so an attachment is under the size limit for email (1)
  • Reduces the size of the files (1) so more of them fit onto a storage device/backup media (1)

Do not accept 'it compresses the files' on its own, as this repeats the question.

Do not accept responses about protecting files from malware/viruses or about deleting files.

Example answers and how they were marked
Full marks2/2

It makes the files smaller (1) so that they use less storage space on the computer and more of them fit on the disk (1).

Why: The point (1) and a linked development giving the benefit (1).

Some marks1/2

It makes files smaller.

Why: This is the point (1) but there is no development of what the smaller size leads to, so only one mark.

No marks0/2

It protects the files from viruses so that they cannot be damaged.

Why: This describes anti-malware software, which the mark scheme does not accept; no creditworthy point is made.

4Discuss6 marksTranslators Swap Remove

A company writes a photo editing program in a high-level language. The company will sell the finished program to customers. Each customer will install the program on their own computer and run it many times.

Discuss whether the company should use a compiler or an interpreter to translate the program before it is sold.

Your answer should include:

  • the output of each type of translator
  • whether the program has to be translated each time it is run
  • what the customer needs on their computer to run the program.
[6 marks]
Mark scheme

Indicative content

The output of each type of translator

  • A compiler translates the whole program in one go and produces object code.
  • The object code is saved as an executable file, which is already in machine code so the processor can run it directly.
  • An interpreter does not produce object code, so no translated file exists for the company to save and sell.
  • An interpreter translates one line at a time and executes it immediately, but that translation is not kept.

Whether the program has to be translated each time it is run

  • Compiled code is translated once, so the executable can be run as many times as the customer likes without being translated again.
  • If the source code is edited, the whole program has to be compiled again to produce a new executable.
  • An interpreted program is translated again every time it is run, so a customer who runs the program often waits for translation at every run.
  • An executable runs faster than interpreted code because it is already in machine code.

What the customer needs on their computer to run the program

  • A customer who installs the executable needs no compiler on their computer, so the program will run straight away.
  • If the company supplied the source code instead, the customer would need an interpreter installed, and it would have to be an interpreter for their type of computer.
  • A customer given only the executable does not have the source code, so cannot change the program.

Conclusion

  • A compiler is the better choice for this company, because the executable can be sold and the customer runs it without it being translated again and without being given the source code.
  • Using an interpreter would mean supplying the source code to customers and translating the program on every run.

Levels

  • Level 0 (0 marks): No rewardable content.
  • Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
  • Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
  • Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Level 3 responses must cover all three bullets for this company's program, including translating once rather than on every run, and reach a conclusion.

Do not accept 'a compiler fixes errors' (a compiler reports syntax errors at the end of translation, it does not fix them) or 'a compiler is easier to use' with no link to output, translation or the customer. Do not accept answers about translating to assembly language.

Example answers and how they were marked
Full marks6/6

The company should use a compiler. A compiler translates the whole program in one go and produces object code, which is saved as an executable file. This executable is already in machine code, so the customer's processor can run it directly. The program is translated only once, so a customer who runs the program many times does not wait for it to be translated again, and it runs faster than interpreted code would. An interpreter produces no object code, so the company would have nothing to sell as an executable. The customer would have to be given the source code and would need an interpreter installed on their computer, and the program would be translated again every time it was run.

Why: Level 3. Covers the output of both translators (executable from the compiler, no object code from the interpreter), the effect of translating once rather than on every run, and what the customer needs on their computer, all applied to the company selling the program, with a clear conclusion.

Some marks3/6

A compiler produces an executable file, which the company can save and sell to its customers. An interpreter does not produce an executable file, so the customer would need the source code and an interpreter installed on their computer to run the program. This means a compiler is better for the company, because customers can just run the file they are given.

Why: Level 2. Gives the output of both translators and links this to what the customer needs, with a conclusion, but never says the compiled program is translated once while an interpreted one is translated on every run, so the reasoning is not developed enough for Level 3.

No marks0/6

The company should use a compiler because it is easier to write programs with a compiler and it fixes the errors in the program before the customers get it.

Why: Level 0. No creditworthy point: 'easier to write programs' is not linked to the output, the translation each run or the customer, and 'fixes the errors' is a misconception, as the mark scheme's guidance says a compiler only reports errors at the end of translation.

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.