Practice
Generated questions on gates, truth tables and boolean expressions, marked as you go. They never run out, and nothing is stored.
Teaching a class? The worksheet generator puts the same questions on paper, with an answer key, from a link everyone can open.
Which gate has this truth table?
| a | b | Q |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
What comes up
Seven kinds of question, mixed at random.
| Question | What it tests | Stuck? Read |
|---|---|---|
| Gate output | Knowing each gate's behaviour cold | The seven logic gates |
| Identify the gate | Reading a truth table backwards | Truth table generator |
| Evaluate an expression | Operator precedence and substitution | Boolean algebra laws |
| Find the equivalent | Simplification and De Morgan | Boolean algebra calculator |
| Count the ones | Building a truth table in your head | Karnaugh map solver |
| Read a circuit | Getting from a gate diagram to an expression | Logic circuit generator |
| Trace a circuit | Following signals through a diagram to its output | Logic circuit generator |
Then build something
Answering questions about gates is a different skill from wiring them up. When a question stops being obvious, build the circuit and watch it.
Questions
Where do the questions come from?
They are built fresh rather than drawn from a fixed list, so you can keep going indefinitely. The wrong answers are real alternatives rather than filler, so you cannot get there by eliminating the obviously silly ones.
What is covered?
Gate outputs, identifying a gate from its truth table, evaluating an expression at given inputs, spotting an equivalent expression, counting the rows where a function is true, and two kinds of question on a gate diagram: reading its expression off it, and tracing signals to its output. That is most of what an introductory digital logic exercise sheet asks.
Is there a time limit or a score to beat?
No timer. The counter tracks how many you have answered, how many were right and your current streak, and nothing is sent anywhere or stored between visits.