Ham Radio General Class Practice Test

What determines the frequency of an LC oscillator?

1. The number of stages in the counter

2. The number of stages in the divider

3. The inductance and capacitance in the tank circuit

4. The time delay of the lag circuit

The correct answer is: The inductance and capacitance in the tank circuit

The frequency of an LC oscillator is primarily determined by the inductance and capacitance in the tank circuit. In an LC oscillator, the combination of an inductor (L) and a capacitor (C) creates a resonant circuit. The resonant frequency (f) can be calculated using the formula: \[ f = \frac{1}{2\pi\sqrt{LC}} \] This formula indicates that the frequency is inversely related to the square root of the product of the inductance and capacitance. Thus, any changes in either the inductance or the capacitance will directly affect the oscillation frequency. For the other options: while the number of stages in a counter or divider might have implications for signal processing or frequency division, they do not directly influence the frequency of the LC oscillator itself. The time delay of a lag circuit pertains to timing and signal phase shifts rather than resonance and frequency generation in an LC tank circuit. Understanding this relationship emphasizes how crucial the components of inductance and capacitance are in determining the characteristics of an LC oscillator.