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AQA · GCSE · Computer Science · Higher

Boolean expression from logic circuit

Q07.3 3 marks

Figure 6 shows a different logic circuit.

Figure 6
Figure 6

Figure 6

Enlarged question image

Figure 6

Write a Boolean expression that represents the logic circuit shown in Figure 6.

You must use the correct symbols for the Boolean operators in your expression.

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Marking points

  1. 1 Combines B and C using the correct AND symbol.
  2. 2 Combines the two circuit branches using the correct OR symbol.
  3. 3 Shows NOT A with an unambiguous overbar over A.

Full-mark answer

Q = overline{A} + B cdot C

Why this answer loses marks

I wrote the gate operations as words instead of Boolean symbols.

The circuit must be represented with the required Boolean operator notation while preserving its operation order.