What causes a junction diode to fail from excessive current?
The correct answer is B: Excessive junction temperature. What causes a junction diode to fail from excessive current is excessive junction temperature. High current causes heating, leading to failure. For amateur radio operators, this is important for diode protection. Understanding this helps when protecting diodes.
Exam Tip
Junction diode failure from excessive current = excessive junction temperature. Think 'E'xcessive 'C'urrent = 'E'xtreme 'C'onditions (temperature). High current causes heating, leading to failure. Not inverse voltage, not insufficient voltage, not carrier depletion - just excessive temperature.
Memory Aid
"Junction diode failure from excessive current = excessive junction temperature. Think 'E'xcessive 'C'urrent = 'T'emperature. High current causes heating, leading to failure. Important for diode protection."
Real-World Application
A junction diode failing from excessive current: It's caused by excessive junction temperature. High current causes the junction to heat up, and if the temperature gets too high, the diode fails. This is the cause - excessive junction temperature.
Key Concepts
Why Other Options Are Wrong
Option A (Excessive inverse voltage): Incorrect. Excessive inverse voltage causes breakdown, not failure from current - excessive temperature from current causes failure. Inverse voltage isn't the cause.
Option C (Insufficient forward voltage): Incorrect. Insufficient forward voltage doesn't cause failure from current - excessive temperature from current causes failure. Insufficient voltage isn't the cause.
Option D (Charge carrier depletion): Incorrect. Charge carrier depletion isn't what causes failure - excessive temperature from current causes failure. Carrier depletion isn't the cause.
题目解析
The correct answer is B: Excessive junction temperature. What causes a junction diode to fail from excessive current is excessive junction temperature. High current causes heating, leading to failure. For amateur radio operators, this is important for diode protection. Understanding this helps when protecting diodes.
考试技巧
Junction diode failure from excessive current = excessive junction temperature. Think 'E'xcessive 'C'urrent = 'E'xtreme 'C'onditions (temperature). High current causes heating, leading to failure. Not inverse voltage, not insufficient voltage, not carrier depletion - just excessive temperature.
记忆口诀
Junction diode failure from excessive current = excessive junction temperature. Think 'E'xcessive 'C'urrent = 'T'emperature. High current causes heating, leading to failure. Important for diode protection.
实际应用示例
A junction diode failing from excessive current: It's caused by excessive junction temperature. High current causes the junction to heat up, and if the temperature gets too high, the diode fails. This is the cause - excessive junction temperature.
错误选项分析
Option A (Excessive inverse voltage): Incorrect. Excessive inverse voltage causes breakdown, not failure from current - excessive temperature from current causes failure. Inverse voltage isn't the cause. Option C (Insufficient forward voltage): Incorrect. Insufficient forward voltage doesn't cause failure from current - excessive temperature from current causes failure. Insufficient voltage isn't the cause. Option D (Charge carrier depletion): Incorrect. Charge carrier depletion isn't what causes failure - excessive temperature from current causes failure. Carrier depletion isn't the cause.
知识点
Junction diode, Fail from excessive current, Excessive junction temperature
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.