Edexcel GCSE Computer Science (1CP2) Exam Questions

• A Decodes instructions (1)
• The only correct answer is A. The correct answer is Decodes instructions.
• B is not correct because the arithmetic logic unit performs arithmetic operations
• C is not correct because main memory stores data and instructions
• D is not correct because registers temporarily store data being processed

• B 7 (1)
• The only correct answer is B. The correct answer is 7 bits.
• A is not correct because 6 bits give only 64 different characters
• C is not correct because 8 bits are used by extended ASCII to give 256 characters
• D is not correct because 16 bits give 65 536 different characters, which is far more than the 128 in ASCII

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 one mark for each of:

• 5 × 1024^3 / 5 × 1024 × 1024 × 1024 / 5 × 2^30, for the number of bytes (1)
• A fully correct expression with × 8 to convert bytes to bits, in any order, e.g. 5 × 1024^3 × 8, 8 × 5 × 2^30 (1)

Accept 5 × 1 073 741 824 × 8.

Accept 5 × 2^33 or 42 949 672 960 as a fully correct expression (2 marks).

Do not accept 5 × 1000^3 × 8, which uses decimal multiples.

Do not accept ÷ 8, which converts bits to bytes.