Edexcel GCSE Computer Science (1CP2) Exam Questions

• C No data is lost and the original file can be recreated (1)
• The only correct answer is C. The correct answer is no data is lost and the original file can be recreated.
• A is not correct because encryption hides data and does not make the file smaller
• B is not correct because permanently removing data is lossy compression
• D is not correct because splitting a file into packets is part of transmission, not compression

• C Data is restored to its original format (1)
• The only correct answer is C. The correct answer is data is restored to its original format.
• A is not correct because encryption changes data so that it cannot be read without a key; it does not restore the data
• B is not correct because permanently removing data to reduce the file size is lossy compression, not decompression
• D is not correct because storing data using fewer bits is compression, not decompression

• C Tebibyte (1)
• The only correct answer is C. The correct answer is tebibyte.
• A is not correct because a gibibyte is 1024 mebibytes
• B is not correct because a mebibyte is 1024 kibibytes
• D is not correct because a terabyte is 1000 gigabytes

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.