Copper behaves as a
- A. Conductor always
- B. Conductor or dielectric depending on field strength
- C. Conductor or dielectric depending on frequency
- D. Conductor or dielectric depending on the electric current density
Answer: C. Conductor or dielectric depending on frequency
Explanation: At low and RF frequencies, conduction current dominates (σ >> ωε), so copper acts as a good conductor; at optical and X-ray frequencies above the plasma frequency, displacement current dominates and it behaves as a dielectric.