Deep Dive: E6C02
The correct answer is B: The comparator changes its output state. What happens when the level of a comparator's input signal crosses the threshold voltage is that the comparator changes its output state. Comparators switch output when input crosses threshold. For amateur radio operators, this is important for digital circuits. Understanding this helps when using comparators.
Why Other Answers Are Wrong
Option A: Incorrect. IC input can be damaged isn't what happens - comparator changes output state. Input damage isn't what happens. Option C: Incorrect. Reference level appears at output isn't what happens - comparator changes output state. Reference level isn't what happens. Option D: Incorrect. Feedback loop becomes unstable isn't what happens - comparator changes output state. Feedback instability isn't what happens.
Exam Tip
Comparator input crosses threshold = comparator changes output state. Think 'C'omparator 'T'hreshold = 'C'hanges 'T'ransition. Comparators switch output when input crosses threshold. Not input damage, not reference level, not feedback instability - just changes output state.
Memory Aid
Comparator input crosses threshold = comparator changes output state. Think 'C'omparator = 'C'hanges state. Comparators switch output when input crosses threshold. Important for digital circuits.
Real-World Example
When a comparator's input signal crosses the threshold voltage: The comparator changes its output state. If input goes above threshold, output goes high; if input goes below threshold, output goes low. This is what happens - output state changes.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E6C
Reference: 2024-2028 Question Pool · E6 - Circuit Components
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E6C topic.