Build a practice paper from 659 exam-style questions, each with its mark scheme and example answers. Print it, or answer it on paper and then open the mark schemes. Or browse the questions by topic.
3 questions · 5 marks
Binary, denary and hexadecimal patterns represent numbers.
Convert the binary pattern 1110 1100 to denary.
Award one mark for:
236
Why: Correct: 128 + 64 + 32 + 8 + 4 = 236 (1).
55
Why: Reads the place values from the wrong end (the left-hand bit as 1), so the value is wrong.
5
Why: Counts the 1s instead of adding their place values.
ASCII is a character set that uses 7 bits to represent each character.
Give two limitations of 7-bit ASCII when it is used to represent text.
Award one mark for any of the following up to a maximum of two marks:
Award a maximum of one mark for the last three bullets, as they are all examples of characters that fall outside the 128 ASCII codes.
Allow 'it can only represent 128 characters, so some characters are missing' for the first bullet.
Do not accept 'it uses 7 bits' / 'it only uses 7 bits' on its own, without saying what this limits.
Do not accept 'it can only store a limited amount of text' / 'it can only store short messages', as 7 bits limits the number of characters available, not the length of a message.
Do not accept 'it can only represent the characters in the ASCII character set', as this repeats the question.
Do not accept 'it is old/out of date' or 'it cannot store numbers'.
Only 128 different characters can be represented, so it cannot store characters from other languages such as Greek.
Why: 128 character limit (1) and characters from other languages (1); two separate creditworthy limitations.
It cannot show accented characters like é and it only uses 7 bits.
Why: Accented characters (1); 'only uses 7 bits' is not qualified, so scores 0.
It only uses 7 bits, so it can only store a small amount of text.
Why: Scores 0: text length is not a limitation of 7-bit ASCII, and 'only uses 7 bits' is unqualified; both Do not accept lines apply.
A school laptop is shared by several teachers.
Describe the purpose of giving each teacher their own user account on the laptop.
Award up to two marks for a linked description such as:
Do not accept responses about the laptop running faster or having more storage because it has more accounts.
Do not accept 'so they can log in' without saying why having separate accounts helps.
Each teacher's files are stored separately, so other teachers cannot open or change their work.
Why: Separate files for each account (1) and other teachers kept out of that work (1).
So that each teacher has their own files.
Why: First point of separate files per account (1), but no development of what this achieves (0).
So the laptop runs faster because each teacher has their own account.
Why: Gives speed as a purpose of user accounts, which is not correct for user management; no creditworthy point.
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