What is the function of a reactance modulator?
The correct answer is D: Produce PM or FM signals by varying a capacitance. What is the function of a reactance modulator is to produce PM or FM signals by varying a capacitance. Reactance modulators vary capacitance (or inductance) to modulate frequency. For amateur radio operators, this is important for modulation. Understanding this helps when working with modulators.
Exam Tip
Reactance modulator function = produce PM or FM signals by varying capacitance. Think 'R'eactance 'M'odulator = 'V'aries 'C'apacitance (PM/FM). Reactance modulators vary capacitance (or inductance) to modulate frequency. Not varying resistance, not AM - just PM/FM by varying capacitance.
Memory Aid
"Reactance modulator function = produce PM or FM signals by varying capacitance. Think 'R'eactance 'M'odulator = 'V'aries 'C'apacitance. Reactance modulators vary capacitance (or inductance) to modulate frequency. Important for modulation."
Real-World Application
A reactance modulator: Its function is to produce PM or FM signals by varying a capacitance. By changing the capacitance in the oscillator circuit, the frequency is modulated. This is the function - PM/FM by varying capacitance.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Producing PM or FM by varying resistance isn't correct - reactance modulator varies capacitance. Varying resistance isn't correct.
Option B: Incorrect. Producing AM signals by varying inductance isn't correct - reactance modulator produces PM/FM by varying capacitance. AM isn't correct.
Option C: Incorrect. Producing AM signals by varying resistance isn't correct - reactance modulator produces PM/FM by varying capacitance. AM isn't correct.
题目解析
The correct answer is D: Produce PM or FM signals by varying a capacitance. What is the function of a reactance modulator is to produce PM or FM signals by varying a capacitance. Reactance modulators vary capacitance (or inductance) to modulate frequency. For amateur radio operators, this is important for modulation. Understanding this helps when working with modulators.
考试技巧
Reactance modulator function = produce PM or FM signals by varying capacitance. Think 'R'eactance 'M'odulator = 'V'aries 'C'apacitance (PM/FM). Reactance modulators vary capacitance (or inductance) to modulate frequency. Not varying resistance, not AM - just PM/FM by varying capacitance.
记忆口诀
Reactance modulator function = produce PM or FM signals by varying capacitance. Think 'R'eactance 'M'odulator = 'V'aries 'C'apacitance. Reactance modulators vary capacitance (or inductance) to modulate frequency. Important for modulation.
实际应用示例
A reactance modulator: Its function is to produce PM or FM signals by varying a capacitance. By changing the capacitance in the oscillator circuit, the frequency is modulated. This is the function - PM/FM by varying capacitance.
错误选项分析
Option A: Incorrect. Producing PM or FM by varying resistance isn't correct - reactance modulator varies capacitance. Varying resistance isn't correct. Option B: Incorrect. Producing AM signals by varying inductance isn't correct - reactance modulator produces PM/FM by varying capacitance. AM isn't correct. Option C: Incorrect. Producing AM signals by varying resistance isn't correct - reactance modulator produces PM/FM by varying capacitance. AM isn't correct.
知识点
Function, Reactance modulator, Produce PM or FM signals, Varying capacitance
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.