What type of semiconductor device is designed for use as a voltage-controlled capacitor?
The correct answer is A: Varactor diode. What type of semiconductor device is designed for use as a voltage-controlled capacitor is a varactor diode. Varactor diodes change capacitance with voltage. For amateur radio operators, this is important for component knowledge. Understanding this helps when using voltage-controlled capacitors.
Exam Tip
Voltage-controlled capacitor = varactor diode. Think 'V'aractor = 'V'ariable 'C'apacitor (voltage-controlled). Varactor diodes change capacitance with voltage. Not tunnel diode, not SCR, not Zener - just varactor diode.
Memory Aid
"Voltage-controlled capacitor = varactor diode. Think 'V'aractor = 'V'ariable capacitance. Varactor diodes change capacitance with voltage. Important for component knowledge."
Real-World Application
A voltage-controlled capacitor: It's a varactor diode. Varactor diodes change their capacitance based on the applied reverse voltage, making them useful for tuning circuits. This is the device - varactor diode.
Key Concepts
Why Other Options Are Wrong
Option B (Tunnel diode): Incorrect. Tunnel diode isn't a voltage-controlled capacitor - varactor diode is. Tunnel diode isn't the device.
Option C (Silicon-controlled rectifier): Incorrect. SCR isn't a voltage-controlled capacitor - varactor diode is. SCR isn't the device.
Option D (Zener diode): Incorrect. Zener diode isn't a voltage-controlled capacitor - varactor diode is. Zener diode isn't the device.
题目解析
The correct answer is A: Varactor diode. What type of semiconductor device is designed for use as a voltage-controlled capacitor is a varactor diode. Varactor diodes change capacitance with voltage. For amateur radio operators, this is important for component knowledge. Understanding this helps when using voltage-controlled capacitors.
考试技巧
Voltage-controlled capacitor = varactor diode. Think 'V'aractor = 'V'ariable 'C'apacitor (voltage-controlled). Varactor diodes change capacitance with voltage. Not tunnel diode, not SCR, not Zener - just varactor diode.
记忆口诀
Voltage-controlled capacitor = varactor diode. Think 'V'aractor = 'V'ariable capacitance. Varactor diodes change capacitance with voltage. Important for component knowledge.
实际应用示例
A voltage-controlled capacitor: It's a varactor diode. Varactor diodes change their capacitance based on the applied reverse voltage, making them useful for tuning circuits. This is the device - varactor diode.
错误选项分析
Option B (Tunnel diode): Incorrect. Tunnel diode isn't a voltage-controlled capacitor - varactor diode is. Tunnel diode isn't the device. Option C (Silicon-controlled rectifier): Incorrect. SCR isn't a voltage-controlled capacitor - varactor diode is. SCR isn't the device. Option D (Zener diode): Incorrect. Zener diode isn't a voltage-controlled capacitor - varactor diode is. Zener diode isn't the device.
知识点
Semiconductor device, Voltage-controlled capacitor, Varactor diode
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.