What is the approximate forward threshold voltage of a silicon junction diode?
The correct answer is C: 0.7 volts. The approximate forward threshold voltage of a silicon junction diode is 0.7 volts. Silicon diodes are the most common type and have this standard forward voltage. For amateur radio operators, this is a fundamental value. Understanding this helps when designing circuits.
Exam Tip
Silicon diode forward voltage = 0.7 volts. Think 'S'ilicon = 'S'even-tenths volt (0.7V). Silicon junction diodes have standard 0.7V forward voltage. Not 0.1V, not 0.3V (germanium), not 1.0V - just 0.7V.
Memory Aid
"Silicon diode forward voltage = 0.7 volts. Think 'S'ilicon = 'S'even-tenths volt. Silicon junction diodes have standard 0.7V forward voltage. Most common diode type."
Real-World Application
You use a silicon diode in a rectifier circuit. The diode starts conducting at about 0.7 volts forward voltage. This is the standard forward voltage for silicon junction diodes - the most common type. Silicon's 0.7V forward voltage is a fundamental value.
Key Concepts
Why Other Options Are Wrong
Option A (0.1 volt): Incorrect. 0.1 volt is too low - that's more like Schottky diodes. Silicon junction diodes are 0.7V.
Option B (0.3 volts): Incorrect. 0.3 volts is for germanium diodes, not silicon. Silicon has higher forward voltage than germanium.
Option D (1.0 volts): Incorrect. 1.0 volt is too high - that's more like LED forward voltage. Silicon junction diodes are 0.7V.
题目解析
The correct answer is C: 0.7 volts. The approximate forward threshold voltage of a silicon junction diode is 0.7 volts. Silicon diodes are the most common type and have this standard forward voltage. For amateur radio operators, this is a fundamental value. Understanding this helps when designing circuits.
考试技巧
Silicon diode forward voltage = 0.7 volts. Think 'S'ilicon = 'S'even-tenths volt (0.7V). Silicon junction diodes have standard 0.7V forward voltage. Not 0.1V, not 0.3V (germanium), not 1.0V - just 0.7V.
记忆口诀
Silicon diode forward voltage = 0.7 volts. Think 'S'ilicon = 'S'even-tenths volt. Silicon junction diodes have standard 0.7V forward voltage. Most common diode type.
实际应用示例
You use a silicon diode in a rectifier circuit. The diode starts conducting at about 0.7 volts forward voltage. This is the standard forward voltage for silicon junction diodes - the most common type. Silicon's 0.7V forward voltage is a fundamental value.
错误选项分析
Option A (0.1 volt): Incorrect. 0.1 volt is too low - that's more like Schottky diodes. Silicon junction diodes are 0.7V. Option B (0.3 volts): Incorrect. 0.3 volts is for germanium diodes, not silicon. Silicon has higher forward voltage than germanium. Option D (1.0 volts): Incorrect. 1.0 volt is too high - that's more like LED forward voltage. Silicon junction diodes are 0.7V.
知识点
Silicon diode, Forward threshold voltage, 0.7 volts, Diode characteristics
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.