Quartz crystal resonator quality factor: Compared to most L–C networks, the Q (quality factor) of a quartz crystal is typically _____.

Introduction / Context:
Quartz crystals are used in oscillators and filters because they provide very stable frequencies and narrow bandwidths. The measure that captures this sharpness of resonance is the quality factor, Q. Crystals have Q values far exceeding those of simple lumped L–C tanks at comparable frequencies.

Given Data / Assumptions:

• Piezoelectric quartz resonator operated near its series or parallel resonance.
• Small-signal, linear regime, typical for timing applications.
• Ambient conditions where aging and temperature drift are not the focus.

Concept / Approach:
Q is defined as 2 * pi * (energy stored per cycle) / (energy dissipated per cycle) and equivalently as f0 / BW for narrowband resonators. Quartz exhibits extremely low loss, so its Q can reach 10^4 to 10^6 depending on cut and frequency, vastly higher than L–C realizations with discrete inductors and capacitors at similar frequencies.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturer datasheets and oscillator design texts list loaded Q values many orders of magnitude above simple L–C tanks, confirming the qualitative statement.

Why Other Options Are Wrong:
Extremely low / less than 10 / ≈ 40: far below observed crystal Q; would lead to very broad, unstable resonance inconsistent with crystal performance.

Common Pitfalls:
Confusing Q with frequency stability metrics like ppm drift; while related in effect, they are distinct specifications.

Final Answer:
extremely high