Edexcel GCSE Computer Science (1CP2) Exam Questions

• B Incremental (1)
• The only correct answer is B. The correct answer is incremental.
• A is not correct because a full backup copies all of the data on a disk
• C is not correct because an off-site backup is stored in a different location
• D is not correct because a scheduled backup runs at set times

Award one mark for any of the following:

• To repair/recover corrupted/damaged files so they can be opened/used again (1)
• To recover as much of the data as possible from a damaged file (1)
• To reconstruct parts of a damaged file (1)

Allow "to fix corrupted files".

Do not accept "to repair the hard disk" (disk repair).

Do not accept "to recover deleted files" (file repair recovers corrupted/damaged files, not deleted ones).

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

• A device driver is software/program (1) that controls a peripheral device (1)
• It translates instructions from the operating system (1) into commands/signals the device understands (1)
• It allows the operating system to communicate with a specific device (1) without needing to know the device's hardware details (1)
• It is installed for a new device (1) so the operating system can use that device (1)

Do not accept responses that say a device driver is hardware or that it makes a device faster.

Do not award 'it is part of the CPU'.

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

• The operating system receives signals/data from the graphics tablet (1) and converts them into data the program can use/process (1)
• The operating system receives data from the graphics tablet (1) and passes/forwards it to the program being used/the active program (1)
• The tablet's device driver receives/interprets the signals/data from the tablet (1) so the operating system can pass the input to the program (1)
• The operating system identifies the graphics tablet as the source of the input (1) so the data is sent to the correct program (1)

Accept 'signals' for 'data' throughout.

Accept reference to the device driver only where it is linked to receiving/interpreting the input (e.g. the driver receives the tablet's signals (1) so the OS can pass data to the program (1)).

Do not accept 'the operating system uses a driver' on its own, without saying what the driver does with the input.

Do not accept generic statements such as 'the operating system runs the tablet' as a description of how input is managed.

Do not accept responses that say the operating system creates/finishes the drawing, or that the tablet stores the input permanently.

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

• Allocates memory/RAM to the process (1) so its instructions and data can be stored (1)
• Loads/moves the program instructions into RAM (1) so the process is ready to run (1)
• Adds the process to the ready queue (1) so it can be scheduled onto the CPU (1)
• Gives the process a process ID (PID)/identifier (1) so the operating system can track/manage it (1)

For both marks, the development must follow/be linked to the point.

Only award one of the first two bullets in any one response; allocating memory and loading into RAM are the same stage.

Accept 'memory' for 'RAM' and vice versa.

Accept 'added to a queue for the processor' for the ready queue point.

Do not accept responses that say the process is run on the CPU straight away.

Do not accept descriptions of the program executing/running its instructions, or of the program file being created/saved.

Do not accept responses about the process being blocked or terminated.

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

• Keeps a record/index of where each file is stored on the disk (1) so that the file can be found and opened when it is needed (1)
• Allocates each file to a folder/directory (1) so that files used for the same purpose are kept together (1)
• Decides where on the disk each new file is written (1) so that it does not overwrite an existing file (1)
• Allocates space on the disk for a file (1) so that the file has somewhere to be saved (1)

Allow 'files are organised into folders so that they are easy to find', with the folder point (1) and its purpose (1).

Do not accept responses that only state that the operating system 'organises' or 'controls' the files, with no way of doing it given.

Do not accept 'stores the files' or 'saves files to the disk' without a way of doing it.

Do not accept responses about backing files up, or about the amount of storage space left on the disk.

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

• Each user/file is given permissions/access rights (1) so other users cannot read/write/open/change that user's files (1)
• A user may be given read-only/read access to a file (1) so they cannot edit/delete/change it (1)
• Each file is given permissions/access rights for different users (1) so the operating system allows/refuses access depending on which user is logged in (1)
• The operating system checks a user's permissions/access rights when a file is opened (1) so a user with read-only/read access cannot save/delete changes (1)

Do not accept responses about asking for a password/username, as this checks who the user is, not what they are allowed to do.

Do not accept 'files are protected/safe' or 'access rights protect files' without saying how access is limited (e.g. read-only access, permissions for different users).

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

• A process is created for the program (1) so that its instructions can be loaded into RAM (1)
• The process is put into the ready state (1) so that it can wait for the CPU to become available (1)
• The operating system adds the process to a queue of ready processes (1) so the scheduler can choose it when the CPU is free (1)
• The operating system allocates the resources the process needs (1) so that it can start running when it is given CPU time (1)

For both marks, the expansion must follow/associate with the statement.

Allow 'main memory' for RAM.

Do not accept 'the browser is downloaded/loaded from the internet'.

Do not accept 'the program is run immediately on the CPU' without the ready step.

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

• Files take up less storage space (1) because compression stores the data using fewer bits/removes redundant or unnecessary data (1)
• Files can be transferred/downloaded faster (1) because there is less data to send over a network (1)
• More files fit on a storage device (1) because each file is smaller (1)
• Email attachments can be sent without exceeding attachment size limits (1) because compression reduces the size of the file (1)

For both marks, the expansion must follow/associate with the statement.

Do not accept 'it makes files smaller' on its own without a named benefit such as using less storage space or faster transfer; this repeats the question.

Do not accept 'compression frees up space by deleting files' as compression does not delete the original file.

Do not accept answers about disk defragmentation as this is a different utility.

Indicative content

User accounts

• Each student and teacher should have their own user account, so the operating system can identify the person who is logged on.
• The operating system keeps a record of all valid users on the computer, so unknown users are not allowed to log in.
• A separate home area or folder can be created for each account, so a student's saved work is kept apart from other users' work.
• An account can be disabled when a student leaves the school, so they can no longer access the computers.

Authentication

• A username and password can be required at login, so only users with the correct details can use the computer.
• The operating system checks the entered password against the stored password for that account before allowing access.
• Users should be encouraged to choose a strong password, which makes it harder for someone else to guess and log in.
• The operating system can lock an account after several failed login attempts, which reduces the chance of someone trying passwords repeatedly.

Benefits for the school

• Many students can share the same computers because each person's files are kept separate.
• Work is less likely to be deleted or changed by another student, because users only see their own files.
• The school can see which account was used on a computer, so misuse can be traced to a user.
• Teachers can be confident that only authorised people can use the library computers.
• The school does not need a separate computer for every student, so it saves money.

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 both user accounts and authentication, and apply them to the school library.

Do not accept general operating system functions such as file management or process management unless they are explicitly linked to managing users.