Menu

Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 659 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

3 questions · 5 marks

Pick again
Print
1Short recall1 markCompression Swap Remove

A company backs up its files to an external hard drive.

Give one reason why the company compresses the files before backing them up.

[1 mark]
Mark scheme

Award one mark for any of the following:

  • More files/data can be stored (in the same storage space) (1)
  • The files take up less storage space (1)
  • The backup is quicker/faster to complete (1)
  • Less data needs to be transferred to the backup device (1)

Do not accept 'makes the files more secure' or 'encrypts the files'.

Example answers and how they were marked
Full marks1/1

The compressed files take up less storage space, so more files can be backed up.

Why: The files take up less storage space (1).

No marks0/1

It reduces the amount of disk fragmentation.

Why: Near-miss: compression does not reduce disk fragmentation.

No marks0/1

It encrypts the files so they are safer if the drive is stolen.

Why: Misconception: compression does not encrypt files, and security is not accepted.

2Describe2 marksCompression Swap Remove

Data can be compressed using lossy or lossless compression.

Describe one difference between lossy compression and lossless compression.

[2 marks]
Mark scheme

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

  • Lossy compression permanently removes/discards some of the data (1) whereas lossless compression keeps all of the original data so the file can be restored/rebuilt exactly (1)
  • Lossy compression cannot reproduce/recreate the original file exactly (1) whereas lossless compression can decompress the file back to its original form (1)
  • Lossy compression can make a file smaller than lossless compression (1) because more of the original data is removed/discarded (1)
  • Lossy compression is used for images/sound/video (1) whereas lossless compression is used where all the original data must be kept, such as program files (1)

Allow one mark for a correct statement about one type of compression only, e.g. 'lossy compression permanently removes some data', with no comparison or development.

Do not accept 'lossy compression loses quality' on its own unless it states that data/information is removed or lost permanently.

Do not accept 'lossy is better' or 'lossless is safer' with no described difference.

Do not award a smaller file size on its own; it must be linked to data being removed or to no data being lost.

Example answers and how they were marked
Full marks2/2

Lossy compression permanently removes some of the data, whereas lossless compression keeps all of the original data so the file can be restored exactly.

Why: Linked difference: lossy permanently removes data (1) and lossless keeps all data so the file is restored exactly (1).

Some marks1/2

Lossy compression permanently removes some of the data.

Why: A correct statement about one type only (1), with no comparison to lossless or development, so the second mark is not earned.

No marks0/2

Lossless compression removes the data that is not needed so the file is smaller, but lossy compression keeps every bit of the data.

Why: The two types are the wrong way round; no creditworthy point, so no marks.

3Explain2 marksUnits & Conversion Swap Remove

A server stores a large amount of data.

The capacity of the server is 16 TiB. Explain one benefit of giving the capacity in tebibytes rather than in bytes.

[2 marks]
Mark scheme

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

  • The capacity is easier to read/write (1) because a tebibyte is 1024^4 bytes so the same capacity in bytes would have many more digits (1)
  • The number is shorter (1) because writing 16 TiB instead of 17 592 186 044 416 bytes uses far fewer digits (1)
  • There is less chance of making a mistake when copying the value (1) because a long byte count of many digits is easy to mistype (1)

For both marks, the expansion must follow/associate with the statement and must refer to the number of digits/length of the value.

Allow 'fewer digits'/'shorter number'/'less chance of error' on its own for the first mark; the second mark needs the linked reason that a tebibyte is 1024^4 bytes, so the value in bytes would be very long/have many more digits.

Do not accept 'it is bigger'/'tebibytes are larger' on its own, as this does not give a benefit of using them.

Do not accept 'easier' on its own without saying what is easier, e.g. fewer digits/shorter number.

Do not accept 'because tebibytes are used for large storage' without a reason about the number of digits/readability.

Example answers and how they were marked
Full marks2/2

It is easier to read because 16 TiB has fewer digits than the same capacity written in bytes, which would be a very long number.

Why: Point that the number is easier to read (1); linked reason that the byte count would have many more digits (1).

Some marks1/2

It uses fewer digits.

Why: States the benefit of fewer digits (1); no linked reason about a tebibyte being 1024^4 bytes so the byte count is very long (0).

No marks0/2

Because a tebibyte is bigger than a byte.

Why: States a fact about the unit, which the mark scheme does not accept on its own; no point about fewer digits or readability, so no mark.

Questions by topic

5.3 Cybersecurity

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.