The direction of the induced current in a wire loop exposed to an electromagnetic wave depends on the orientation of the loop with respect to the wave's electric and magnetic fields. The phenomenon is governed by Faraday's law of electromagnetic induction.
According to Faraday's law, when a time-varying magnetic field passes through a wire loop, an induced electromotive force (emf) is generated, which subsequently leads to an induced current in the loop. The direction of the induced current is determined by Lenz's law, which states that the induced current flows in a direction that opposes the change in the magnetic field that produced it.
To determine the direction of the induced current in a wire loop exposed to an electromagnetic wave, you need to consider the relative orientations of the loop and the wave's electric and magnetic fields. Here are two possible scenarios:
Magnetic field perpendicular to the loop: If the wire loop lies in a plane perpendicular to the direction of the magnetic field component of the electromagnetic wave, then the induced current will flow in a specific direction. Applying the right-hand rule, if you curl your right-hand fingers in the direction of the changing magnetic field, your thumb will point in the direction of the induced current.
Electric field perpendicular to the loop: If the wire loop lies in a plane perpendicular to the direction of the electric field component of the electromagnetic wave, then the induced current will flow in the opposite direction. Applying the right-hand rule again, if you curl your right-hand fingers in the direction of the changing electric field, your thumb will point in the direction of the induced current.
In both cases, the actual direction of the induced current will depend on the specific orientations of the loop and the electromagnetic wave. The relative magnitudes of the electric and magnetic fields and the time-varying nature of the fields will also affect the strength of the induced current.