Deep Dive: E6A08
The correct answer is D: Alpha cutoff frequency. What is the term for the frequency at which the grounded-base current gain of a bipolar junction transistor has decreased to 0.7 of the gain obtainable at 1 kHz is alpha cutoff frequency. Alpha cutoff is where current gain drops to 0.7. For amateur radio operators, this is important for transistor knowledge. Understanding this helps when working with transistors.
Why Other Answers Are Wrong
Option A (Corner frequency): Incorrect. Corner frequency isn't the term - alpha cutoff frequency is. Corner frequency isn't the term. Option B (Alpha rejection frequency): Incorrect. Alpha rejection frequency isn't the term - alpha cutoff frequency is. Alpha rejection isn't the term. Option C (Beta cutoff frequency): Incorrect. Beta cutoff frequency is for common-emitter, not grounded-base - alpha cutoff is for grounded-base. Beta cutoff isn't the term.
Exam Tip
Frequency where grounded-base gain drops to 0.7 = alpha cutoff frequency. Think 'A'lpha 'C'utoff = 'A'pplies to grounded-'B'ase (alpha). Alpha cutoff is where current gain drops to 0.7. Not corner frequency, not alpha rejection, not beta cutoff - just alpha cutoff frequency.
Memory Aid
Frequency where grounded-base gain drops to 0.7 = alpha cutoff frequency. Think 'A'lpha 'C'utoff = 'G'rounded-'B'ase. Alpha cutoff is where current gain drops to 0.7. Important for transistor knowledge.
Real-World Example
The frequency at which the grounded-base current gain of a BJT has decreased to 0.7 of the gain obtainable at 1 kHz: It's called the alpha cutoff frequency. This is the frequency limit for grounded-base operation. This is the term - alpha cutoff frequency.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E6A
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 E6A topic.