Deep Dive: E6B03
The correct answer is B: Band gap. What property of an LED's semiconductor material determines its forward voltage drop is band gap. The band gap determines the forward voltage of an LED. For amateur radio operators, this is important for LED knowledge. Understanding this helps when working with LEDs.
Why Other Answers Are Wrong
Option A (Intrinsic resistance): Incorrect. Intrinsic resistance isn't what determines forward voltage - band gap is. Intrinsic resistance isn't the property. Option C (Junction capacitance): Incorrect. Junction capacitance isn't what determines forward voltage - band gap is. Junction capacitance isn't the property. Option D (Junction depth): Incorrect. Junction depth isn't what determines forward voltage - band gap is. Junction depth isn't the property.
Exam Tip
LED forward voltage determined by = band gap. Think 'L'ED 'F'orward 'V'oltage = 'B'and 'G'ap. The band gap determines the forward voltage of an LED. Not intrinsic resistance, not junction capacitance, not junction depth - just band gap.
Memory Aid
LED forward voltage determined by = band gap. Think 'L'ED = 'B'and 'G'ap. The band gap determines the forward voltage of an LED. Important for LED knowledge.
Real-World Example
An LED's forward voltage drop: It's determined by the band gap of the LED's semiconductor material. Different materials have different band gaps, resulting in different forward voltages (e.g., red LEDs ~1.8V, blue LEDs ~3.5V). This is the property - band gap.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E6B
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 E6B topic.