Digital Electronics: Logic Gates & Boolean Algebra
Digital Electronics: Logic Gates & Boolean Algebra is one of 9 topics in the Grade 12 Electrical Technology CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. A two-input AND gate produces a logic 1 output under which condition?
Only when ALL inputs are logic 1
When AT LEAST ONE input is logic 1
Only when ALL inputs are logic 0
An AND gate never produces a logic 1 output
Answer: Only when ALL inputs are logic 1 — An AND gate produces a logic 1 output only when all of its inputs are logic 1 simultaneously.
Easy
2. What does a NOT gate (inverter) do to its single input?
Produces the opposite (inverted) output
Produces exactly the same output as the input
Combines the input with a second signal
Always produces a logic 1 output regardless of input
Answer: Produces the opposite (inverted) output — A NOT gate takes a single input and produces the opposite (inverted) output: logic 0 in produces logic 1 out, and logic 1 in produces logic 0 out.
Medium
3. Name the table that lists every possible input combination and the resulting output for a logic gate.
Answer: truth table — A truth table lists every possible input combination for a logic gate and the resulting output for each combination.
