Metal detectors, like the ones used at airports, are activated by
A) magnetic fields.
B) alternating current.
C) electromagnetic induction.
D) electric fields.

Question

Quizplus · Accepted Answer

Metal detectors work on the principle of electromagnetic induction. They generate an alternating current in a coil, which produces a changing magnetic field. If a metal object is close to the coil, the changing magnetic field induces currents in the object, which in turn create their own magnetic fields and are detected by the detector.

Metal Detectors, Like the Ones Used at Airports, Are Activated