What determines the frequency of an LC oscillator?
The correct answer is C: The inductance and capacitance in the tank circuit. What determines the frequency of an LC oscillator is the inductance and capacitance in the tank circuit. The resonant frequency is f = 1/(2π√LC). For amateur radio operators, this is fundamental oscillator theory. Understanding this helps when designing oscillators.
Exam Tip
LC oscillator frequency = inductance and capacitance in tank circuit. Think 'L'C 'O'scillator = 'L' and 'C' determine frequency. Resonant frequency f = 1/(2π√LC) depends on L and C values. Not counter stages, not divider stages, not lag circuit - just L and C.
Memory Aid
"LC oscillator frequency = inductance and capacitance in tank circuit. Think 'L'C 'O'scillator = 'L' and 'C' determine frequency. Resonant frequency f = 1/(2π√LC) depends on L and C. Fundamental oscillator theory."
Real-World Application
An LC oscillator: The tank circuit has 10 µH inductance and 100 pF capacitance. Frequency = 1/(2π√(10×10⁻⁶ × 100×10⁻¹²)) = 5.03 MHz. The inductance and capacitance in the tank circuit determine the oscillator frequency. This is fundamental LC oscillator theory.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Counter stages don't determine LC oscillator frequency - counters are for digital circuits, not LC oscillators. Counter stages aren't relevant.
Option B: Incorrect. Divider stages don't determine LC oscillator frequency - dividers reduce frequency, not determine it. Divider stages aren't relevant.
Option D: Incorrect. Time delay of lag circuit doesn't determine LC oscillator frequency - LC oscillators use tank circuits, not lag circuits. Lag circuits aren't relevant.
题目解析
The correct answer is C: The inductance and capacitance in the tank circuit. What determines the frequency of an LC oscillator is the inductance and capacitance in the tank circuit. The resonant frequency is f = 1/(2π√LC). For amateur radio operators, this is fundamental oscillator theory. Understanding this helps when designing oscillators.
考试技巧
LC oscillator frequency = inductance and capacitance in tank circuit. Think 'L'C 'O'scillator = 'L' and 'C' determine frequency. Resonant frequency f = 1/(2π√LC) depends on L and C values. Not counter stages, not divider stages, not lag circuit - just L and C.
记忆口诀
LC oscillator frequency = inductance and capacitance in tank circuit. Think 'L'C 'O'scillator = 'L' and 'C' determine frequency. Resonant frequency f = 1/(2π√LC) depends on L and C. Fundamental oscillator theory.
实际应用示例
An LC oscillator: The tank circuit has 10 µH inductance and 100 pF capacitance. Frequency = 1/(2π√(10×10⁻⁶ × 100×10⁻¹²)) = 5.03 MHz. The inductance and capacitance in the tank circuit determine the oscillator frequency. This is fundamental LC oscillator theory.
错误选项分析
Option A: Incorrect. Counter stages don't determine LC oscillator frequency - counters are for digital circuits, not LC oscillators. Counter stages aren't relevant. Option B: Incorrect. Divider stages don't determine LC oscillator frequency - dividers reduce frequency, not determine it. Divider stages aren't relevant. Option D: Incorrect. Time delay of lag circuit doesn't determine LC oscillator frequency - LC oscillators use tank circuits, not lag circuits. Lag circuits aren't relevant.
知识点
LC oscillator, Frequency determination, Inductance and capacitance, Tank circuit
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.