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Computer Architecture and Operation
Quick questions on Logic gates and Boolean algebra explained: H2 Computing
8short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What are the logic gates?Show answer
A logic gate outputs a 1 or 0 from its binary inputs. The core gates:
What are truth tables?Show answer
A truth table lists the output for every input combination. With inputs there are rows, since each input is independently 0 or 1:
What are boolean expressions?Show answer
A Boolean expression describes a circuit algebraically, for example . Build it by combining the gate operations; evaluate it row by row to get its truth table.
What are boolean algebra laws?Show answer
Boolean algebra lets you simplify expressions to use fewer gates (cheaper, faster circuits). Key laws:
What are universal gates?Show answer
NAND (and NOR) is a universal gate: every other gate, and therefore any circuit, can be built from NAND alone. This matters in manufacturing - a chip can be made from one repeated gate type.
What is q1?Show answer
How many rows does a truth table with four inputs have, and why? [2 marks]
What is q2?Show answer
State De Morgan's law for the negation of an AND. [1 mark]
What is q3?Show answer
Why is NAND called a universal gate? [2 marks]