Edexcel GCSE Computer Science (1CP2) Exam Questions

Award one mark for any of the following up to a maximum of two marks:

• An arithmetic operation, e.g. addition/subtraction/multiplication/division (1)
• A logical operation, e.g. comparing two values (is A > B?) / using AND, OR, NOT (1)

Do not accept decoding instructions, fetching instructions or controlling the timing of the CPU, as these are carried out by the control unit.

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

• Carries out arithmetic operations/calculations, such as addition or subtraction (1) so that the result can be stored in a register (1)
• Carries out logical operations, such as comparing two data items (1) to see which one is greater/larger (1)
• Compares two data items (1) to decide whether a condition is true / which path a program takes next (1)

Allow the result of an arithmetic or logical operation being held/stored in a register, but only where the operation is named.

Do not accept answers that say the ALU stores data or results without naming an operation (registers/main memory store data).

Do not accept answers about controlling components, decoding instructions or timing (that is the control unit or the clock).

Do not award credit for 'it processes data' on its own; an arithmetic or a logical operation must be named.

An example on its own, e.g. 'it adds two numbers', does not earn a second mark; the second mark needs a linked development.

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

• The battery lasts longer/needs charging less often (1) because embedded systems have low power consumption/use less power (1)
• It can be made small/light enough to wear on the wrist (1) because the processor, memory and input/output are combined on a single chip/microcontroller (1)
• It can carry out the step-counting function reliably (1) because it runs a single/dedicated program and cannot install other software (1)
• It has a low cost per unit (1) because it uses fewer/less powerful components than a general purpose computer (1)

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

Award one mark for a valid point stated on its own, e.g. 'it is small/light enough to wear on the wrist' (1) or 'its battery lasts longer before it needs charging' (1).

Accept the same linked ideas in either order, e.g. 'it uses less power (1) so the battery lasts longer (1)'.

Do not accept 'it uses less power'/'low power' on its own as a complete explanation; it must be linked to the battery lasting longer/needing charging less often for the second mark.

Do not accept an expansion that simply restates the point, e.g. 'it is small (1) so it fits on the wrist' earns only the point mark; 'fits on the wrist' is not a linked cause and is not enough for the second mark.

Do not accept 'the battery is small' as the linked reason for low power consumption.

Do not accept responses that say other software/apps can be installed on an embedded system (0); embedded systems have a single/dedicated function and cannot install new software.

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

• Data is stored as electric charges (1) which are trapped/held in the memory cells/chips (1)
• A current forces electrons through a barrier (1) and they stay trapped on the other side until another current/'flash' is applied (1)
• A cell that is holding trapped electrons/a charge represents a 1 (1) and a cell with no charge represents a 0 (1)

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

Allow one mark for stating that data is stored as electric charges/electrons without a linked reason.

Do not accept 'there are no moving parts' or 'it is fast/durable' - these are characteristics of solid state storage, not how data is stored.

Do not accept 'data is stored magnetically' or 'as pits and lands'.