When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This…

When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on
  1. Electromagnetic induction
  2. Resonance in ac circuits
  3. Mutual induction in ac circuits
  4. interference of electromagnetic waves

Solution

Metal detector works on the principle of transmitting an electromagnetic signal and analyses a return signal from the target. So it works on the principle of resonance in AC circuit.

When the LC circuit detects any resonating frequency from any metal which is near to it, electric field will be created which will lead to induces current in the coil and changes in the signal flow through the coil.

Asked in: JEE Main 2022 (25 Jul Shift 2)

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