How is positive feedback supplied in a Pierce oscillator?
Through a tapped coil
Through link coupling
Through a neutralizing capacitor
Through a quartz crystal✓Правильный ответ
Объяснение
In a Pierce oscillator the quartz crystal itself is the feedback element between output and input. The loop therefore has enough gain and the right phase only at the crystal's resonant frequency, which is what fixes the frequency of oscillation.