Edexcel GCSE Computer Science (1CP2) Exam Questions

• A Blu-ray Disc (1)
• The only correct answer is A. The correct answer is Blu-ray Disc.
• B is not correct because a CD stores less data than a Blu-ray Disc, up to about 700 MB
• C is not correct because a DVD stores less data than a Blu-ray Disc, up to about 4.7 GB (single-layer) or 8.4 GB (dual-layer)
• D is not correct because magnetic tape is not an optical storage medium

• A Address bus (1)
• The only correct answer is A. The correct answer is address bus. Do not accept 'address' on its own.
• B is not correct because the control bus carries control signals in both directions between the CPU and other components
• C is not correct because the data bus carries data in both directions between the CPU and main memory
• D is not correct because the system bus is the collection of all three buses

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

• A read/write head moves over the surface of the disk (1) to read/write data by detecting or changing the magnetic alignment of areas of the surface (1)
• The head magnetises areas of the disk surface in different directions (1) so each area represents a binary 1 or 0 (1)
• Data is stored on concentric circles called tracks (1) which are divided into sectors (1)

Allow one mark for tracks/concentric circles on their own.

For the second mark in the first two bullets, the response must refer to the magnetic alignment/charge being detected or changed, not just that the head reads/writes data.

Do not award a mark for 'it is magnetic' or 'it stores data in binary' with no description of how the data is stored.

Do not accept descriptions of optical storage (e.g. a laser, pits and lands) or solid state storage (e.g. electric charges in chips).

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

• RAM is volatile (memory) (1) because it needs a constant/continuous power supply to hold/store the data it contains (1)
• Data is held in RAM as electrical states/charges (1) so when the power supply is removed these states cannot be kept/refreshed and the data is lost (1)
• RAM is used as short-term storage for the data and instructions currently in use (1) because it can only hold them while the computer has power (1)

For both marks, the expansion must follow/associate with the statement and must link the loss of the data to the power supply being removed.

Accept 'RAM is volatile' on its own for the first mark; the second mark is only awarded for a linked reason about the power supply.

Do not accept 'RAM is temporary/short-term memory' or 'RAM is cleared when the computer is switched off' on its own for both marks, as neither gives a reason.

Do not accept answers that say the data is deleted/cleared/erased by the computer or the operating system, or that the data is saved/moved to secondary storage, without saying why the data cannot be kept (e.g. because RAM needs power/is volatile).