Build a practice paper from 693 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 · 4 marks
Computers manipulate binary patterns.
Convert the binary pattern 1110 0000 to denary.
Award one mark for:
224
Why: Correct: 128 + 64 + 32 = 224 (1).
7
Why: Reads the place values from the wrong end (the left-hand bit as 1), so the value is wrong.
3
Why: Counts the 1s instead of adding their place values.
A bitmap image uses one bit per pixel.
State the limitation this places on the number of colours in the image.
Award one mark for any of the following:
Allow answers that give the number of colours, e.g. two colours, 2 colours
Allow any pair of two colours, e.g. black and white, black and grey
Do not accept low resolution/poor quality/lower quality
Do not accept only one colour/can only show black
Do not accept 2 bits/2^1 without a statement about the number of colours that can be represented
Only two colours can be represented, such as black and white.
Why: States that only two different colours can be represented (1)
The image will have a low resolution.
Why: Confuses colour depth with resolution; low resolution is not accepted
The image can only show black.
Why: One colour is all a single value can give; the limitation is that only two colours can be represented, so this is not accepted
Computers manipulate binary patterns.
Convert the denary number 184 to 8-bit binary.
Award one mark for each correct nibble in the correct order:
0 marks if the response is not 8-bit binary.
1011 1000
Why: 184 = 128 + 32 + 16 + 8: both nibbles are correct (2).
1011 1001
Why: Converts 185 instead (a slip in adding up the place values). The first nibble is correct (1); the second is not.
0001 1101
Why: The bits are written in reverse, smallest place value first. Neither nibble is correct.
Teachers: build a paper, print it with the mark schemes at the end, and sign your school up to set your classes activities on every topic.
Fetch Decode Explain isn't affiliated with or endorsed by Pearson Edexcel.