What is the most useful characteristic of a Zener diode?
The correct answer is B: A constant voltage drop under conditions of varying current. What is the most useful characteristic of a Zener diode is a constant voltage drop under conditions of varying current. Zener diodes maintain constant voltage over a range of currents. For amateur radio operators, this is important for voltage regulation. Understanding this helps when using Zener diodes.
Exam Tip
Zener diode characteristic = constant voltage drop under varying current. Think 'Z'ener = 'Z'ero voltage change (constant voltage). Zener diodes maintain constant voltage over a range of currents. Not constant current, not negative resistance, not varying capacitance - just constant voltage drop.
Memory Aid
"Zener diode characteristic = constant voltage drop under varying current. Think 'Z'ener = 'C'onstant 'V'oltage. Zener diodes maintain constant voltage over a range of currents. Important for voltage regulation."
Real-World Application
A Zener diode: Its most useful characteristic is a constant voltage drop under conditions of varying current. This makes Zener diodes ideal for voltage regulation - they maintain a stable voltage even as current changes. This is the characteristic - constant voltage drop.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Constant current drop under varying voltage isn't correct - Zener diodes have constant voltage drop. Constant current isn't the characteristic.
Option C: Incorrect. Negative resistance region isn't the characteristic - Zener diodes have constant voltage drop. Negative resistance isn't the characteristic.
Option D: Incorrect. Internal capacitance varying with voltage isn't the characteristic - Zener diodes have constant voltage drop. Varying capacitance isn't the characteristic.
题目解析
The correct answer is B: A constant voltage drop under conditions of varying current. What is the most useful characteristic of a Zener diode is a constant voltage drop under conditions of varying current. Zener diodes maintain constant voltage over a range of currents. For amateur radio operators, this is important for voltage regulation. Understanding this helps when using Zener diodes.
考试技巧
Zener diode characteristic = constant voltage drop under varying current. Think 'Z'ener = 'Z'ero voltage change (constant voltage). Zener diodes maintain constant voltage over a range of currents. Not constant current, not negative resistance, not varying capacitance - just constant voltage drop.
记忆口诀
Zener diode characteristic = constant voltage drop under varying current. Think 'Z'ener = 'C'onstant 'V'oltage. Zener diodes maintain constant voltage over a range of currents. Important for voltage regulation.
实际应用示例
A Zener diode: Its most useful characteristic is a constant voltage drop under conditions of varying current. This makes Zener diodes ideal for voltage regulation - they maintain a stable voltage even as current changes. This is the characteristic - constant voltage drop.
错误选项分析
Option A: Incorrect. Constant current drop under varying voltage isn't correct - Zener diodes have constant voltage drop. Constant current isn't the characteristic. Option C: Incorrect. Negative resistance region isn't the characteristic - Zener diodes have constant voltage drop. Negative resistance isn't the characteristic. Option D: Incorrect. Internal capacitance varying with voltage isn't the characteristic - Zener diodes have constant voltage drop. Varying capacitance isn't the characteristic.
知识点
Zener diode, Most useful characteristic, Constant voltage drop, Varying current
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.