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?
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.
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 Application
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.
Key Concepts
Why Other Options 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.
题目解析
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.
考试技巧
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.
记忆口诀
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.
实际应用示例
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.
错误选项分析
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.
知识点
Frequency, Grounded-base current gain, Bipolar junction transistor, Decreased to 0.7, Gain at 1 kHz, Alpha cutoff frequency
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.