Ch 4 · Truth Tables · Theory

Topic 4 of 10 in Boolean Logic & Logic Gates — How Machines Decide — 2 lessons.

The Complete Behaviour of a Circuit

A truth table lists every possible combination of inputs and the output for each. For n inputs there are 2ⁿ rows: 2 inputs → 4 rows, 3 inputs → 8 rows.

A Truth-Table Generator

This evaluates the expression (A AND B) OR NOT C for all 8 combinations — exactly what you'd fill in by hand in an exam, but instant.

All topics in Theory Boolean-logic

1. Why Logic Gates
2. NOT, AND, OR
3. NAND, NOR, XOR
4. Truth Tables
5. From Problem to Circuit
6. Logic Expressions
7. Boolean Algebra (A Level)
8. Karnaugh Maps & Flip-Flops (A Level)
9. Gates That Do Arithmetic
10. Check Your Understanding