Deep Dive: E6F03
The correct answer is D: An LED and a phototransistor. What is the most common configuration of an optoisolator or optocoupler is an LED and a phototransistor. Most optoisolators use LED + phototransistor. For amateur radio operators, this is important for optoelectronics knowledge. Understanding this helps when using optoisolators.
Why Other Answers Are Wrong
Option A: Incorrect. Lens and photomultiplier isn't common - LED and phototransistor is. Lens/photomultiplier isn't common. Option B: Incorrect. Frequency-modulated helium-neon laser isn't common - LED and phototransistor is. FM laser isn't common. Option C: Incorrect. Amplitude-modulated helium-neon laser isn't common - LED and phototransistor is. AM laser isn't common.
Exam Tip
Most common optoisolator configuration = LED and phototransistor. Think 'O'ptoisolator = 'L'ED + 'P'hototransistor. Most optoisolators use LED + phototransistor. Not lens/photomultiplier, not FM laser, not AM laser - just LED and phototransistor.
Memory Aid
Most common optoisolator configuration = LED and phototransistor. Think 'O'ptoisolator = 'L'ED + 'P'hototransistor. Most optoisolators use LED + phototransistor. Important for optoelectronics knowledge.
Real-World Example
An optoisolator or optocoupler: The most common configuration is an LED and a phototransistor. The LED emits light, and the phototransistor detects it, providing electrical isolation. This is the configuration - LED and phototransistor.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E6F
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 E6F topic.