Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E7A
E7A10E7A

What is a truth table?

Deep Dive: E7A10

The correct answer is B: A list of inputs and corresponding outputs for a digital device. What is a truth table is a list of inputs and corresponding outputs for a digital device. Truth tables show all input/output combinations. For amateur radio operators, this is important for digital circuits. Understanding this helps when analyzing logic.

Why Other Answers Are Wrong

Option A: Incorrect. List for op-amp isn't truth table - truth table is for digital devices. Op-amp isn't truth table. Option C: Incorrect. Diagram showing logic states when output is true isn't truth table - truth table is a list of inputs/outputs. Diagram isn't truth table. Option D: Incorrect. Table of logic symbols for op-amp isn't truth table - truth table is for digital devices. Op-amp symbols isn't truth table.

Exam Tip

Truth table = list of inputs and corresponding outputs for digital device. Think 'T'ruth 'T'able = 'T'able of 'T'ruth (input/output combinations). Truth tables show all input/output combinations. Not op-amp, not diagram, not op-amp symbols - just list of inputs/outputs for digital device.

Memory Aid

Truth table = list of inputs and corresponding outputs for digital device. Think 'T'ruth 'T'able = 'I'nput/'O'utput list. Truth tables show all input/output combinations. Important for digital circuits.

Real-World Example

A truth table: It's a list of inputs and corresponding outputs for a digital device. For example, an AND gate truth table shows: 0,0→0; 0,1→0; 1,0→0; 1,1→1. This is what a truth table is - input/output list.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E7A

Reference: 2024-2028 Question Pool · E7 - Practical Circuits

Key Concepts

Truth table List of inputs Corresponding outputs Digital device

Official Pool Source

Question text and answer key are synchronized with the current NCVEC Extra Class pool and mapped to the E7A topic.