Resonance, Bandwidth & Q Factor
When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on:
Show answer and solution
Answer: (b)
- A metal detector has an LC circuit tuned to resonance with its coil.
- A metal object changes the coil's effective inductance, shifting the circuit off resonance.
- The resulting change in current is detected and triggers the alarm.
- So the answer is (b) resonance in ac circuits.