Edexcel GCSE Computer Science (1CP2) Exam Questions

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:

• The operating system switches rapidly between processes (1) so each process runs for a short time slice before the next one starts (1)
• Each process is given a small amount of CPU time (1) so the CPU moves on to another process when that time is up (1)
• The operating system chooses which process to run next (1) so the CPU is shared between the programs (1)
• Processes take turns to use the CPU (1) because the CPU is so fast the user does not notice the switching (1)
• Only one process can run on the CPU at a time (1) so the operating system must swap processes in and out quickly (1)

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

Allow 'time slice' / 'time quantum'.

Do not accept 'the computer has more than one CPU' / 'each program runs on its own CPU'.

Do not accept 'the CPU does two things at once' without saying processes take turns/are switched.

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.

Indicative content

Administrator accounts

• An administrator account can create new user accounts for new employees and delete accounts when employees leave.
• The administrator can reset a forgotten password, so an employee can get back to work without sharing another person's account.
• The administrator can set the access rights for each user or group, so designers get access to project folders and only directors can open salary files.
• Administrator privileges should be given to only a few trusted employees, as administrators can change any settings on the system.

Standard user accounts

• Designers should use standard user accounts, so they cannot install unauthorised software or change system settings.
• A standard user can be given permission to read and write files in the project folder that their team uses.
• Standard users should not be able to change other users' permissions, so the access rules cannot be removed by accident.
• If a standard user tries to open a file without permission, the operating system denies access.

File permissions

• Each file or folder can have permissions that allow a user to read, write or delete it.
• Project folders can be set so all designers can read and write the files inside them.
• Salary files can be set so only directors can read them, and other users are denied access.
• Permissions can be set for a group of users, such as all designers, which is quicker than setting them for each person.
• A file can be made read-only for standard users, so they can view it but cannot change it.

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 administrator accounts, standard user accounts and file permissions, and apply them to the design company.

Do not accept general operating system functions such as managing the processor or memory unless they are explicitly linked to controlling what a user can access.