Boolean Logic · 5 question types
Past paper frequency (2018 to 2024)
This topic accounts for approximately 9% of your exam marks.
Truth tables and Boolean expressions from circuit diagrams appear in every paper. 4 to 6 marks.
The opposite direction is also examined: you are given a Boolean expression and have to draw the circuit.
Method. (1) Read the expression inside out: innermost brackets first, then NOT, then AND, then OR. (2) Use one gate per operator. (3) Wire each gate's inputs to the correct preceding signal (a labelled input variable, or the output of an earlier gate). (4) Make sure NOT gates appear before the negated value enters its next gate. (5) Label the last gate's output
Q(or whatever name the question uses).