Back to the full dot-point answer
WalesComputer ScienceQuick questions
Unit 1 Fundamentals of Computer Science
Quick questions on Logical operations: Boolean algebra, logic gates and truth tables - WJEC A-Level Computer Science
5short 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
Each gate has a standard symbol and a truth table. NAND and NOR are called universal gates because any logic function can be built from NAND gates alone, or from NOR gates alone, which matters when manufacturing a chip from a single gate type.
What are truth tables?Show answer
A truth table lists every possible combination of the inputs and the resulting output. For n inputs there are 2 to the power n rows: two inputs give four rows, three inputs give eight. Building a truth table for a compound expression means adding a column for each intermediate part and working left to right, evaluating the innermost brackets first.
What is simplifying a circuit?Show answer
Fewer gates means lower cost, lower power and faster operation, so simplification is not just algebra for its own sake: it is how real circuits are made efficient.
What is q1?Show answer
Write down the truth table output column for A NAND B for the input rows 00, 01, 10, 11. [2 marks]
What is q2?Show answer
Use De Morgan's law to rewrite NOT (A OR B). [1 mark]
Have a question we have not covered?
This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.